3 CGI::Ex::Template - Fast and lightweight TT2/3 template engine
7 my $t = CGI::Ex::Template->new(
8 INCLUDE_PATH => ['/path/to/templates'],
18 $t->process('my/template.tt', $swap)
21 ### Anything in the Template::Toolkit SYNOPSIS would fit here also
25 CGI::Ex::Template happened by accident (accidentally on purpose). The
26 CGI::Ex::Template (CET hereafter) was originally a part of the CGI::Ex
27 suite that performed simple variable interpolation. It used TT2 style
28 variables in TT2 style tags "[% foo.bar %]". That was all the
29 original CGI::Ex::Template did. This was fine and dandy for a couple
30 of years. In winter of 2005-2006 CET was revamped to add a few
31 features. One thing led to another and soon CET provided for most of
32 the features of TT2 as well as some from TT3. CGI::Ex::Template is a
33 full-featured implementation of the Template::Toolkit language.
35 CGI::Ex::Template (CET hereafter) is smaller, faster, uses less memory
36 and less CPU than TT2. However, it is most likely less portable, less
37 extendable, and probably has many of the bugs that TT2 has already massaged
38 out from years of bug reports and patches from a very active community
39 and mailing list. CET does not have a vibrant community behind it. Fixes
40 applied to TT2 will take longer to get into CET, should they get in at all.
41 An attempt will be made to follow updates made to TT2 to keep the two
42 in sync at a language level. There already has been, and it is expected that
43 there will continue to be code sharing between the two projects. (Acutally
44 I will try and keep applicable fixes in sync with TT).
46 Most of the standard Template::Toolkit documentation covering directives,
47 variables, configuration, plugins, filters, syntax, and vmethods should
48 apply to CET just fine (This pod tries to explain everything - but there is
49 too much). The section on differences between CET and TT will explain
50 what too look out for.
52 Note: A clarification on "faster". All templates are going to take
53 different amounts of time to process. Different types of DIRECTIVES
54 parse and play more quickly than others. The test script
55 samples/benchmark/bench_template.pl was used to obtain sample numbers.
56 In general the following statements are true:
58 If you load a new Template object each time and pass a filename, CET
59 is around 4 times faster.
61 If you load a new Template object and pass a string ref, CET
62 is around 3.5 times faster.
64 If you load a new Template object and use CACHE_EXT, CET
65 is around 1.5 times faster.
67 If you use a cached object with a cached in memory template,
68 then CET is 50% faster.
70 If you use Template::Stash::XS with a cached in memory template,
71 then CET is about as fast.
73 Using TT with a compiled-in-memory template is only 33%
74 faster than CET with a new object compiling each time.
76 It is pretty hard to beat the speed of XS stash with compiled in
77 memory templates. Many systems don't have access to those so
78 CET may make more sense. Hopefully as TT is revised, many of the CET
79 speed advantages can be incorporated so that the core TT is just as
82 So should you use CGI::Ex::Template ? Well, try it out. It may
83 give you no visible improvement. Or it could.
88 The following section lists most of the publicly available methods. Some less
89 commonly used public methods are listed later in this document.
95 my $obj = CGI::Ex::Template->new({
96 INCLUDE_PATH => ['/my/path/to/content', '/my/path/to/content2'],
99 Arguments may be passed as a hash or as a hashref. Returns a CGI::Ex::Template object.
101 There are currently no errors during CGI::Ex::Template object creation.
105 This is the main method call for starting processing. Any errors that result in the
106 template processing being stopped will be stored and available via the ->error method.
108 Process takes three arguments.
110 $t->process($in, $swap, $out)
113 The $in argument can be any one of:
115 String containing the filename of the template to be processed. The filename should
116 be relative to INCLUDE_PATH. (See INCLUDE_PATH, ABSOLUTE, and RELATIVE configuration items).
117 In memory caching and file side caching are available for this type.
119 A reference to a scalar containing the contents of the template to be processed.
121 A coderef that will be called to return the contents of the template.
123 An open filehandle that will return the contents of the template when read.
125 The $swap argument should be hashref containing key value pairs that will be
126 available to variables swapped into the template. Values can be hashrefs, hashrefs
127 of hashrefs and so on, arrayrefs, arrayrefs of arrayrefs and so on, coderefs, objects,
128 and simple scalar values such as numbers and strings. See the section on variables.
130 The $out argument can be any one of:
132 undef - meaning to print the completed template to STDOUT.
134 String containing a filename. The completed template will be placed in the file.
136 A reference to a string. The contents will be appended to the scalar reference.
138 A coderef. The coderef will be called with the contents as a single argument.
140 An object that can run the method "print". The contents will be passed as
141 a single argument to print.
143 An arrayref. The contents will be pushed onto the array.
145 An open filehandle. The contents will be printed to the open handle.
147 Additionally - the $out argument can be configured using the OUTPUT configuration
150 =item C<process_simple>
152 Similar to the process method but with the following restrictions:
154 The $in parameter is limited to a filename or a reference a string containing the contents.
156 The $out parameter may only be a reference to a scalar string that output will be appended to.
158 Additionally, the following configuration variables will be ignored: VARIABLES,
159 PRE_DEFINE, BLOCKS, PRE_PROCESS, PROCESS, POST_PROCESS, AUTO_RESET, OUTPUT.
163 Should something go wrong during a "process" command, the error that occurred can
164 be retrieved via the error method.
166 $obj->process('somefile.html', {a => 'b'}, \$string_ref)
169 =item C<define_vmethod>
171 This method is available for defining extra Virtual methods or filters. This method is similar
172 to Template::Stash::define_vmethod.
178 Add WRAPPER configuration item (the WRAPPER directive is supported).
180 Add ERROR config item
182 =head1 HOW IS CGI::Ex::Template DIFFERENT
184 CET uses the same base template syntax and configuration items as TT2,
185 but the internals of CET were written from scratch. Additionally much
186 of the planned TT3 syntax is supported. The following is a list of
187 some of the ways that the configuration and syntax of CET are
188 different from that of TT2. Note: items that are planned to work in
189 TT3 are marked with (TT3).
193 =item Numerical hash keys work
197 =item Quoted hash key interpolation is fine
199 [% a = {"$foo" => 1} %]
201 =item Multiple ranges in same constructor
203 [% a = [1..10, 21..30] %]
205 =item Constructor types can call virtual methods. (TT3)
207 [% a = [1..10].reverse %]
211 [% 123.length %] # = 3
213 [% 123.4.length %] # = 5
215 [% -123.4.length %] # = -5 ("." binds more tightly than "-")
223 =item The "${" and "}" variable interpolators can contain expressions,
226 [% [0..10].${ 1 + 2 } %] # = 4
228 [% {ab => 'AB'}.${ 'a' ~ 'b' } %] # = AB
230 [% color = qw/Red Blue/; FOR [1..4] ; color.${ loop.index % color.size } ; END %]
233 =item Arrays can be accessed with non-integer numbers.
235 [% [0..10].${ 2.3 } %] # = 3
237 =item Reserved names are less reserved. (TT3)
239 [% GET GET %] # gets the variable named "GET"
241 [% GET $GET %] # gets the variable who's name is stored in "GET"
243 =item Filters and SCALAR_OPS are interchangeable. (TT3)
249 =item Pipe "|" can be used anywhere dot "." can be and means to call
250 the virtual method. (TT3)
252 [% a = {size => "foo"} %][% a.size %] # = foo
254 [% a = {size => "foo"} %][% a|size %] # = 1 (size of hash)
256 =item Pipe "|" and "." can be mixed. (TT3)
258 [% "aa" | repeat(2) . length %] # = 4
260 =item Added Virtual Object Namespaces. (TT3)
262 The Text, List, and Hash types give direct access
265 [% a = "foobar" %][% Text.length(a) %] # = 6
267 [% a = [1 .. 10] %][% List.size(a) %] # = 10
269 [% a = {a=>"A", b=>"B"} ; Hash.size(a) %] = 2
271 [% foo = {a => 1, b => 2}
273 | List.join(", ") %] # = a, b
275 =item Added "as" scalar, list, and hash virtual methods.
277 [% list.as("%s", ", ") %]
279 [% hash.as("%s => %s", "\n") %]
281 =item Whitespace is less meaningful. (TT3)
283 [% 2-1 %] # = 1 (fails in TT2)
285 =item Added pow operator.
287 [% 2 ** 3 %] [% 2 pow 3 %] # = 8 8
289 =item Added self modifiers (+=, -=, *=, /=, %=, **=, ~=). (TT3)
291 [% a = 2; a *= 3 ; a %] # = 6
292 [% a = 2; (a *= 3) ; a %] # = 66
294 =item Added pre and post increment and decrement (++ --). (TT3)
296 [% ++a ; ++a %] # = 12
297 [% a-- ; a-- %] # = 0-1
299 =item Added qw// contructor. (TT3)
301 [% a = qw(a b c); a.1 %] # = b
303 [% qw/a b c/.2 %] # = c
305 =item Allow for scientific notation. (TT3)
309 [% 123.as('%.3e') %] # = 1.230e+02
311 =item Allow for hexidecimal input. (TT3)
313 [% a = 0xff0000 %][% a %] # = 16711680
315 [% a = 0xff2 / 0xd; a.as('%x') %] # = 13a
317 =item FOREACH variables can be nested.
319 [% FOREACH f.b = [1..10] ; f.b ; END %]
321 Note that nested variables are subject to scoping issues.
322 f.b will not be reset to its value before the FOREACH.
324 =item Post operative directives can be nested. (TT3)
326 Andy Wardley calls this side-by-side effect notation.
328 [% one IF two IF three %]
332 [% IF three %][% IF two %][% one %][% END %][% END %]
335 [% a = [[1..3], [5..7]] %][% i FOREACH i = j FOREACH j = a %] # = 123567
337 =item Semi-colons on directives in the same tag are optional. (TT3)
343 [% FOREACH i = [1 .. 10]
347 Note: a semi-colon is still required in front of any block directive
348 that can be used as a post-operative directive.
357 =item CATCH blocks can be empty.
359 TT2 requires them to contain something.
361 =item Added a DUMP directive.
363 Used for Data::Dumpering the passed variable or expression.
367 =item CET does not generate Perl code.
369 It generates an "opcode" tree.
371 =item CET uses storable for its compiled templates.
373 If EVAL_PERL is off, CET will not eval_string on ANY piece of information.
375 =item There is no context.
377 CET provides a context object that mimics the Template::Context
378 interface for use by some TT filters, eval perl blocks, and plugins.
380 =item There is no stash.
382 Well there is but it isn't an object.
384 CET only supports the variables passed in VARIABLES, PRE_DEFINE, and
385 those passed to the process method. CET provides a stash object that
386 mimics the Template::Stash interface for use by some TT filters, eval
387 perl blocks, and plugins.
389 =item There is no provider.
391 CET uses the load_parsed_tree method to get and cache templates.
393 =item There is no grammar.
395 CET has its own built in recursive grammar system.
397 =item There is no VIEW directive.
400 =item There are no references.
402 There was in initial beta tests, but it was decided to remove the little used feature.
404 It makes it the same as
406 [% obj.method("foo") %]
408 This is removed in CET.
410 =item The DEBUG directive is more limited.
412 It only understands DEBUG_DIRS (8) and DEBUG_UNDEF (2).
414 =item When debug dirs is on, directives on different lines separated by colons show the line they
415 are on rather than a general line range.
417 =item There is no ANYCASE configuration item.
419 There was in initial beta tests, but it was dropped in favor of consistent parsing syntax.
421 =item There is no V1DOLLAR configuration item.
423 This is a TT version 1 compatibility item and is not available in CET.
429 This section discusses how to use variables and expressions in the TT mini-language.
431 A variable is the most simple construct to insert into the TT mini language. A variable
432 name will look for the matching value inside CGI::Ex::Templates internal stash of variables
433 which is essentially a hash reference. This stash is initially populated by either passing
434 a hashref as the second argument to the process method, or by setting the "VARIABLES" or
435 "PRE_DEFINE" configuration variables.
437 ### some sample variables
442 some_code => sub { "You passed me (".join(', ', @_).")" },
446 c => [3, 1, 4, 1, 5, 9],
449 my_list => [20 .. 50],
450 cet => CGI::Ex::Template->new,
453 ### pass the variables into the CET process
454 $cet->process($template_name, \%vars)
457 ### pass the variables during object creation (will be available to every process call)
458 my $cet = CGI::Ex::Template->new(VARIABLES => \%vars);
460 =head2 GETTING VARIABLES
462 Once you have variables defined, they can be used directly in the template by using their name
463 in the stash. Or by using the GET directive.
469 Would print when processed:
475 To access members of a hashref or an arrayref, you can chain together the names using a ".".
478 [% my_list.0] [% my_list.1 %] [% my_list.-1 %]
487 If the value of a variable is a code reference, it will be called. You can add a set of parenthesis
488 and arguments to pass arguments. Arguments are variables and can be as complex as necessary.
493 [% some_code(one, 2, 3) %]
500 You passed me (1.0, 2, 3).
502 If the value of a variable is an object, methods can be called using the "." operator.
506 [% cet.dump_parse('1 + 2').replace('\s+', ' ') %]
508 Would print something like:
510 CGI::Ex::Template=HASH(0x814dc28)
512 $VAR1 = [ \[ '+', '1', '2' ], 0 ];
514 Each type of data (string, array and hash) have virtual methods
515 associated with them. Virtual methods allow for access to functions
516 that are commonly used on those types of data. For the full list of
517 built in virtual methods, please see the section titled VIRTUAL
522 [% some_data.c.join(" | ") %]
530 It is also possible to "interpolate" variable names using a "$". This allows for storing
531 the name of a variable inside another variable. If a variable name is a little
532 more complex it can be embedded inside of "${" and "}".
536 [% ${some_data.vname} %]
538 [% some_data.${foo} %]
548 In CET it is also possible to embed any expression (non-directive) in "${" and "}"
549 and it is possible to use non-integers for array access. (This is not available in TT2)
551 [% ['a'..'z'].${ 2.3 } %]
552 [% {ab => 'AB'}.${ 'a' ~ 'b' } %]
553 [% color = qw/Red Blue/; FOR [1..4] ; color.${ loop.index % color.size } ; END %]
561 =head2 SETTING VARIABLES.
563 To define variables during processing, you can use the = operator. In most cases
564 this is the same as using the SET directive.
567 [% SET b = "Hello" %][% b %]
574 It is also possible to create arrayrefs and hashrefs.
577 [% b = {key1 => 'val1', 'key2' => 'val2'} %]
580 [% b.key1 %] [% b.key2 %]
587 It is possible to set multiple values in the same SET directive.
592 [% a %] [% b %] [% c %]
598 It is also possible to unset variables, or to set members of
599 nested data structures.
614 =head1 LITERALS AND CONSTRUCTORS
616 The following are the types of literals (numbers and strings) and
617 constructors (hash and array constructs) allowed in CET. They can be
618 used as arguments to functions, in place of variables in directives,
619 and in place of variables in expressions. In CET it is also possible
620 to call virtual methods on literal values.
624 =item Integers and Numbers.
626 [% 23423 %] Prints an integer.
627 [% 3.14159 %] Prints a number.
628 [% pi = 3.14159 %] Sets the value of the variable.
629 [% 3.13159.length %] Prints 7 (the string length of the number)
631 Scientific notation is supported.
633 [% 314159e-5 + 0 %] Prints 3.14159.
635 [% .0000001.as('%.1e') %] Prints 1.0e-07
637 Hexidecimal input is also supported.
639 [% 0xff + 0 %] Prints 255
641 [% 48875.as('%x') %] Prints beeb
643 =item Single quoted strings.
645 Returns the string. No variable interpolation happens.
647 [% 'foobar' %] Prints "foobar".
648 [% '$foo\n' %] Prints "$foo\\n". # the \\n is a literal "\" and an "n"
649 [% 'That\'s nice' %] Prints "That's nice".
650 [% str = 'A string' %] Sets the value of str.
651 [% 'A string'.split %] Splits the string on ' ' and returns the list.
653 Note: virtual methods can only be used on literal strings in CET, not in TT.
655 =item Double quoted strings.
657 Returns the string. Variable interpolation happens.
659 [% "foobar" %] Prints "foobar".
660 [% "$foo" %] Prints "bar" (assuming the value of foo is bar).
661 [% "${foo}" %] Prints "bar" (assuming the value of foo is bar).
662 [% "foobar\n" %] Prints "foobar\n". # the \n is a newline.
663 [% str = "Hello" %] Sets the value of str.
664 [% "foo".replace('foo','bar') %] Prints "bar".
666 Note: virtual methods can only be used on literal strings in CET, not in TT.
668 =item Array Constructs.
670 [% [1, 2, 3] %] Prints something like ARRAY(0x8309e90).
671 [% array1 = [1 .. 3] %] Sets the value of array1.
672 [% array2 = [foo, 'a', []] %] Sets the value of array2.
673 [% [4, 5, 6].size %] Prints 3.
674 [% [7, 8, 9].reverse.0 %] Prints 9.
676 Note: virtual methods can only be used on array contructs in CET, not in TT.
678 =item Quoted Array Constructs.
680 [% qw/1 2 3/ %] Prints something like ARRAY(0x8309e90).
681 [% array1 = qw{Foo Bar Baz} %] Sets the value of array1.
682 [% qw[4 5 6].size %] Prints 3.
683 [% qw(Red Blue).reverse.0 %] Prints Blue.
685 Note: this works in CET and is planned for TT3.
687 =item Hash Constructs.
689 [% {foo => 'bar'} %] Prints something like HASH(0x8305880)
690 [% hash = {foo => 'bar', c => {}} %] Sets the value of hash.
691 [% {a => 'A', b => 'B'}.size %] Prints 2.
692 [% {'a' => 'A', 'b' => 'B'}.size %] Prints 2.
694 [% {Tom => 'You are Tom',
695 Kay => 'You are Kay'}.$name %] Prints You are Tom
697 Note: virtual methods can only be used on hash contructs in CET, not in TT.
701 Expressions are one or more variables or literals joined together with
702 operators. An expression can be used anywhere a variable can be used
703 with the exception of the variable name in the SET directive, and the
704 filename of PROCESS, INCLUDE, WRAPPER, and INSERT.
706 The following section shows some samples of expressions. For a full list
707 of available operators, please see the section titled OPERATORS.
710 [% 1 + 2 * 3 %] Prints 7
711 [% (1 + 2) * 3 %] Prints 9
715 [% z = x * (y - 1) %] Prints 4
717 =head1 VIRTUAL METHODS
719 The following is the list of builtin virtual methods and filters that
720 can be called on each type of data.
722 In CGI::Ex::Template, the "|" operator can be used to call virtual
723 methods just the same way that the "." operator can. The main
724 difference between the two is that on access to hashrefs or objects,
725 the "|" means to always call the virtual method or filter rather than
726 looking in the hashref for a key by that name, or trying to call that
727 method on the object. This is similar to how TT3 will function.
729 Virtual methods are also made available via Virtual Objects which
730 are discussed in a later section.
732 =head2 SCALAR VIRTUAL METHODS AND FILTERS
734 The following is the list of builtin virtual methods and filters
735 that can be called on scalar data types. In CET and TT3, filters and
736 virtual methods are more closely related than in TT2. In general anywhere a
737 virtual method can be used a filter can be used also - and likewise all scalar
738 virtual methods can be used as filters.
740 In addition to the filters listed below, CET will automatically load
741 Template::Filters and use them if Template::Toolkit is installed.
743 In addition to the scalar virtual methods, any scalar will be
744 automatically converted to a single item list if a list virtual method
747 Scalar virtual methods are also available through the "Text" virtual
748 object (except for true filters such as eval and redirect).
754 [% item = 'foo' %][% item.0 %] Returns self. Allows for scalars to mask as arrays.
760 Similar to format. Returns a string formatted with the passed pattern. Default pattern is %s.
764 [% item.chunk(60).join("\n") %] Split string up into a list of chunks of text 60 chars wide.
768 [% item.collapse %] Strip leading and trailing whitespace and collapse all other space to one space.
772 [% item.defined %] Always true - because the undef sub translates all undefs to ''.
776 [% item.indent(3) %] Indent that number of spaces.
778 [% item.indent("Foo: ") %] Add the string "Foo: " to the beginning of every line.
784 Process the string as though it was a template. This will start the parsing
785 engine and will use the same configuration as the current process. CET is several times
786 faster at doing this than TT is and is considered acceptable.
788 This is a filter and is not available via the Text virtual object.
792 Same as the eval filter.
796 Same as the redirect filter.
800 [% item.format('%d') %] Print the string out in the specified format. Each line is
801 processed separately.
805 [% item.hash %] Returns a one item hash with a key of "value" and a value of the item.
809 [% item.html %] Performs a very basic html encoding (swaps out &, <, > and " for the html entities)
813 [% item.int %] Return the integer portion of the value (0 if none).
817 [% item.lcfirst %] Capitalize the leading letter.
821 [% item.length %] Return the length of the string.
825 [% item.list %] Returns a list with a single value of the item.
829 [% item.lower %] Return a lower-casified string.
833 [% item.match("(\w+) (\w+)") %] Return a list of items matching the pattern.
835 [% item.match("(\w+) (\w+)", 1) %] Same as before - but match globally.
839 [% item.null %] Do nothing.
843 [% item = 10; item.rand %] Returns a number greater or equal to 0 but less than 10.
846 Note: This filter is not available as of TT2.15.
850 [% item.remove("\s+") %] Same as remove - but is global and replaces with nothing.
854 [% item.redirect("output_file.html") %]
856 Writes the contents out to the specified file. The filename
857 must be relative to the OUTPUT_PATH configuration variable and the OUTPUT_PATH variable must be set.
859 This is a filter and is not available via the Text virtual object.
863 [% item.repeat(3) %] Repeat the item 3 times
865 [% item.repeat(3, ' | ') %] Repeat the item 3 times separated with ' | '
869 [% item.replace("\s+", " ") %] Globally replace all space with
871 [% item.replace("foo", "bar", 0) Replace only the first instance of foo with bar.
873 [% item.replace("(\w+)", "($1)") %] Surround all words with parenthesis.
877 [% item.search("(\w+)" %] Tests if the given pattern is in the string.
881 [% item.size %] Always returns 1.
885 [% item.split %] Returns an arrayref from the item split on " "
887 [% item.split("\s+") %] Returns an arrayref from the item split on /\s+/
889 [% item.split("\s+", 3) %] Returns an arrayref from the item split on /\s+/ splitting until 3 elements are found.
893 [% item.stderr %] Print the item to the current STDERR handle.
897 [% item.substr(i) %] Returns a substring of item starting at i and going to the end of the string.
899 [% item.substr(i, n) %] Returns a substring of item starting at i and going n characters.
903 [% item.trim %] Strips leading and trailing whitespace.
907 [% item.ucfirst %] Lower-case the leading letter.
911 [% item.upper %] Return a upper-casified string.
915 [% item.uri %] Perform a very basic URI encoding.
919 =head2 LIST VIRTUAL METHODS
921 The following methods can be called on an arrayref type data structures (scalar
922 types will automatically promote to a single element list and call these methods
925 Additionally, list virtual methods can be accessed via the List
932 [% mylist.as('%s', ', ') %]
934 Passed a pattern and an string to join on. Returns a string of the values of the list
935 formatted with the passed pattern and joined with the passed string.
936 Default pattern is %s and the default join string is a space.
940 [% mylist.first(3) %] Returns a list of the first 3 items in the list.
944 [% mylist.grep("^\w+\.\w+$") %] Returns a list of all items matching the pattern.
948 [% mylist.hash %] Returns a hashref with the array indexes as keys and the values as values.
952 [% mylist.join %] Joins on space.
953 [% mylist.join(", ") Joins on the passed argument.
957 [% mylist.last(3) %] Returns a list of the last 3 items in the list.
961 [% mylist.list %] Returns a reference to the list.
965 [% mylist.max %] Returns the last item in the array.
969 [% mylist.merge(list2) %] Returns a new list with all defined items from list2 added.
973 [% mylist.nsort %] Returns the numerically sorted items of the list. If the items are
974 hashrefs, a key containing the field to sort on can be passed.
978 [% mylist.pop %] Removes and returns the last element from the arrayref (the stash is modified).
982 [% mylist.push(23) %] Adds an element to the end of the arrayref (the stash is modified).
986 [% mylist.random %] Returns a random item from the list.
987 [% ['a' .. 'z'].random %]
989 Note: This filter is not available as of TT2.15.
993 [% mylist.reverse %] Returns the list in reverse order.
997 [% mylist.shift %] Removes and returns the first element of the arrayref (the stash is modified).
1001 [% mylist.size %] Returns the number of elements in the array.
1005 [% mylist.slice(i, n) %] Returns a list from the arrayref beginning at index i and continuing for n items.
1009 [% mylist.sort %] Returns the alphabetically sorted items of the list. If the items are
1010 hashrefs, a key containing the field to sort on can be passed.
1014 [% mylist.splice(i, n) %] Removes items from array beginning at i and continuing for n items.
1016 [% mylist.splice(i, n, list2) %] Same as before, but replaces removed items with the items
1021 [% mylist.unique %] Return a list of the unique items in the array.
1025 [% mylist.unshift(23) %] Adds an item to the beginning of the arrayref.
1029 =head2 HASH VIRTUAL METHODS
1031 The following methods can be called on hash type data structures:
1033 Additionally, list virtual methods can be accessed via the Hash
1040 [% myhash.as('%s => %s', "\n") %]
1042 Passed a pattern and an string to join on. Returns a string of the key/value pairs
1043 of the hash formatted with the passed pattern and joined with the passed string.
1044 Default pattern is "%s\t%s" and the default join string is a newline.
1048 [% myhash.defined('a') %] Checks if a is defined in the hash.
1052 [% myhash.delete('a') %] Deletes the item from the hash.
1056 [% myhash.each.join(", ") %] Turns the contents of the hash into a list - subject
1057 to change as TT is changing the operations of each and list.
1061 [% myhash.exists('a') %] Checks if a is in the hash.
1065 [% myhash.hash %] Returns a reference to the hash.
1069 [% myhash.import(hash2) %] Overlays the keys of hash2 over the keys of myhash.
1073 [% myhash.item(key) %] Returns the hashes value for that key.
1077 [% myhash.items %] Returns a list of the key and values (flattened hash)
1081 [% myhash.keys.join(', ') %] Returns an arrayref of the keys of the hash.
1085 [% myhash.list %] Returns an arrayref with the hash as a single value (subject to change).
1089 [% myhash.pairs %] Returns an arrayref of hashrefs where each hash contains {key => $key, value => $value}
1090 for each value of the hash.
1094 [% myhash.nsort.join(", ") %] Returns a numerically sorted list of the keys.
1098 [% myhash.size %] Returns the number of key/value pairs in the hash.
1102 [% myhash.sort.join(", ") Returns an alphabetically sorted list.
1106 [% myhash.values.join(', ') %] Returns an arrayref of the values of the hash.
1110 =head1 VIRTUAL OBJECTS
1112 TT3 has a concept of Text, List, and Hash virtual objects which provide
1113 direct access to the scalar, list, and hash virtual methods. In the TT3
1114 engine this will allow for more concise generated code. Because CET does
1115 not generated perl code to be executed later, CET provides for these virtual
1116 objects but does so as more of a namespace (using the methods does not
1117 provide a speed optimization in your template - just may help clarify things).
1119 [% a = "foo"; a.length %] => 3
1121 [% a = "foo"; Text.length(a) %] => 3
1123 [% a = Text.new("foo"); a.length %] => 3
1126 [% a = [1 .. 30]; a.size %] => 30
1128 [% a = [1 .. 30]; List.size(a) %] => 30
1130 [% a = List.new(1 .. 30); a.size %] => 30
1133 [% a = {a => 1, b => 2}; a.size %] => 2
1135 [% a = {a => 1, b => 2}; Hash.size(a) %] => 2
1137 [% a = Hash.new({a => 1, b => 2}); a.size %] => 2
1139 [% a = Hash.new(a => 1, b => 2); a.size %] => 2
1141 [% a = Hash.new(a = 1, b = 2); a.size %] => 2
1143 [% a = Hash.new('a', 1, 'b', 2); a.size %] => 2
1145 One limitation is that if you pass a key named "Text",
1146 "List", or "Hash" in your variable stash - the corresponding
1147 virtual object will be hidden.
1149 Additionally, you can use all of the Virtual object methods with
1154 | List.join(", ") %] => a, b
1156 Again, there aren't any speed optimizations to using the virtual
1157 objects in CET, but it can help clarify the intent in some cases.
1159 Note: these aren't really objects. All of the "virtual objects" are
1160 references to the $SCALAR_OPS, $LIST_OPS, and $HASH_OPS hashes
1161 found in the $VOBJS hash of CGI::Ex::Template.
1165 This section contains the alphabetical list of DIRECTIVES available in
1166 the TT language. DIRECTIVES are the "functions" and control
1167 structures of the Template Toolkit mini-language. For further
1168 discussion and examples beyond what is listed below, please refer to
1169 the TT directives documentation.
1171 [% IF 1 %]One[% END %]
1172 [% FOREACH a = [1 .. 3] %]
1176 [% SET a = 1 %][% SET a = 2 %][% GET a %]
1178 Multiple directives can be inside the same set of '[%' and '%]' tags
1179 as long as they are separated by space or semi-colons (;). Any block
1180 directive that can also be used as a post-operative directive (such as
1181 IF, WHILE, FOREACH, UNLESS, FILTER, and WRAPPER) must be separated
1182 from preceding directives with a semi-colon if it is being used as a
1183 block directive. It is more safe to always use a semi-colon. Note:
1184 separating by space is only available in CET but is a planned TT3
1187 [% SET a = 1 ; SET a = 2 ; GET a %]
1194 IF 0 # is a post-operative
1198 IF 0 # it is block based
1203 The following is the list of directives.
1209 Saves a block of text under a name for later use in PROCESS, INCLUDE,
1210 and WRAPPER directives. Blocks may be placed anywhere within the
1211 template being processed including after where they are used.
1213 [% BLOCK foo %]Some text[% END %]
1221 [% BLOCK foo %]Some text[% END %]
1227 Anonymous BLOCKS can be used for capturing.
1229 [% a = BLOCK %]Some text[% END %][% a %]
1235 Anonymous BLOCKS can be used with macros.
1240 Alias for LAST. Used for exiting FOREACH and WHILE loops.
1244 Calls the variable (and any underlying coderefs) as in the GET method, but
1245 always returns an empty string.
1249 Used with the SWITCH directive. See the L</"SWITCH"> directive.
1253 Used with the TRY directive. See the L</"TRY"> directive.
1257 Clears any of the content currently generated in the innermost block
1258 or template. This can be useful when used in conjunction with the TRY
1259 statement to clear generated content if an error occurs later.
1263 Used to reset the DEBUG_FORMAT configuration variable, or to turn
1264 DEBUG statements on or off. This only has effect if the DEBUG_DIRS or
1265 DEBUG_ALL flags were passed to the DEBUG configuration variable.
1267 [% DEBUG format '($file) (line $line) ($text)' %]
1273 Similar to SET, but only sets the value if a previous value was not
1274 defined or was zero length.
1276 [% DEFAULT foo = 'bar' %][% foo %] => 'bar'
1278 [% foo = 'baz' %][% DEFAULT foo = 'bar' %][% foo %] => 'baz'
1282 This is not provided in TT. DUMP inserts a Data::Dumper printout
1283 of the variable or expression. If no argument is passed it will
1284 dump the entire contents of the current variable stash (with
1285 private keys removed.
1287 If the template is being processed in a web request, DUMP will html
1288 encode the DUMP automatically.
1290 [% DUMP %] # dumps everything
1296 Used with the IF directive. See the L</"IF"> directive.
1300 Used with the IF directive. See the L</"IF"> directive.
1304 Used to end a block directive.
1308 Used to apply different treatments to blocks of text. It may operate as a BLOCK
1309 directive or as a post operative directive. CET supports all of the filters in
1310 Template::Filters. The lines between scalar virtual methods and filters is blurred (or
1311 non-existent) in CET. Anything that is a scalar virtual method may be used as a FILTER.
1313 TODO - enumerate the at least 7 ways to pass and use filters.
1317 Alias for the FILTER directive. Note that | is similar to the
1318 '.' in CGI::Ex::Template. Therefore a pipe cannot be used directly after a
1319 variable name in some situations (the pipe will act only on that variable).
1320 This is the behavior employed by TT3.
1324 Used with the TRY directive. See the L</"TRY"> directive.
1332 Allows for iterating over the contents of any arrayref. If the variable is not an
1333 arrayref, it is automatically promoted to one.
1335 [% FOREACH i IN [1 .. 3] %]
1336 The variable i = [% i %]
1340 [% FOREACH j IN a %]
1341 The variable j = [% j %]
1354 You can also use the "=" instead of "IN" or "in".
1356 [% FOREACH i = [1 .. 3] %]
1357 The variable i = [% i %]
1362 Setting into a variable is optional.
1365 [% FOREACH a %] Hi [% END %]
1371 If the item being iterated is a hashref and the FOREACH does not
1372 set into a variable, then values of the hashref are copied into
1375 [% FOREACH [{a => 1}, {a => 2}] %]
1384 The FOREACH process uses the CGI::Ex::Template::Iterator class to handle
1385 iterations (It is compatible with Template::Iterator). During the FOREACH
1386 loop an object blessed into the iterator class is stored in the variable "loop".
1388 The loop variable provides the following information during a FOREACH:
1390 index - the current index
1391 max - the max index of the list
1392 size - the number of items in the list
1395 first - true if on the first item
1396 last - true if on the last item
1397 next - return the next item in the list
1398 prev - return the previous item in the list
1402 [% FOREACH [1 .. 3] %] [% loop.count %]/[% loop.size %] [% END %]
1408 The iterator is also available using a plugin. This allows for access
1409 to multiple "loop" variables in a nested FOREACH directive.
1411 [%~ USE outer_loop = Iterator(["a", "b"]) %]
1412 [%~ FOREACH i = outer_loop %]
1413 [%~ FOREACH j = ["X", "Y"] %]
1414 [% outer_loop.count %]-[% loop.count %] = ([% i %] and [% j %])
1425 FOREACH may also be used as a post operative directive.
1427 [% "$i" FOREACH i = [1 .. 5] %] => 12345
1431 Return the value of a variable or expression.
1435 The GET keyword may be omitted.
1439 [% 7 + 2 - 3 %] => 6
1441 See the section on VARIABLES.
1443 =item C<IF (IF / ELSIF / ELSE)>
1445 Allows for conditional testing. Expects an expression as its only
1446 argument. If the expression is true, the contents of its block are
1447 processed. If false, the processor looks for an ELSIF block. If an
1448 ELSIF's expression is true then it is processed. Finally it looks for
1449 an ELSE block which is processed if none of the IF or ELSIF's
1450 expressions were true.
1452 [% IF a == b %]A equaled B[% END %]
1456 [%- ELSIF a == c -%]
1459 Couldn't determine that A equaled anything.
1462 IF may also be used as a post operative directive.
1464 [% 'A equaled B' IF a == b %]
1468 Parse the contents of a file or block and insert them. Variables defined
1469 or modifications made to existing variables are discarded after
1470 a template is included.
1472 [% INCLUDE path/to/template.html %]
1474 [% INCLUDE "path/to/template.html" %]
1476 [% file = "path/to/template.html" %]
1479 [% BLOCK foo %]This is foo[% END %]
1482 Arguments may also be passed to the template:
1484 [% INCLUDE "path/to/template.html" a = "An arg" b = "Another arg" %]
1486 Filenames must be relative to INCLUDE_PATH unless the ABSOLUTE
1487 or RELATIVE configuration items are set.
1491 Insert the contents of a file without template parsing.
1493 Filenames must be relative to INCLUDE_PATH unless the ABSOLUTE
1494 or RELATIVE configuration items are set.
1498 Used to exit out of a WHILE or FOREACH loop.
1502 Takes a directive and turns it into a variable that can take arguments.
1504 [% MACRO foo(i, j) BLOCK %]You passed me [% i %] and [% j %].[% END %]
1506 [%~ foo("a", "b") %]
1511 You passed me a and b.
1512 You passed me 1 and 2.
1516 [% MACRO bar(max) FOREACH i = [1 .. max] %]([% i %])[% END %]
1526 Used to define variables that will be available via either the
1527 template or component namespace.
1529 Once defined, they cannot be overwritten.
1531 [% template.foobar %]
1532 [%~ META foobar = 'baz' %]
1533 [%~ META foobar = 'bing' %]
1541 Used to go to the next iteration of a WHILE or FOREACH loop.
1545 Only available if the EVAL_PERL configuration item is true (default is false).
1547 Allow eval'ing the block of text as perl. The block will be parsed and then eval'ed.
1552 print "The variable \$a was \"$a\"";
1553 $stash->set('b', "FooBar");
1559 The variable $a was "BimBam"
1562 During execution, anything printed to STDOUT will be inserted into the template. Also,
1563 the $stash and $context variables are set and are references to objects that mimic the
1564 interface provided by Template::Context and Template::Stash. These are provided for
1565 compatibility only. $self contains the current CGI::Ex::Template object.
1569 Parse the contents of a file or block and insert them. Unlike INCLUDE,
1570 no variable localization happens so variables defined or modifications made
1571 to existing variables remain after the template is processed.
1573 [% PROCESS path/to/template.html %]
1575 [% PROCESS "path/to/template.html" %]
1577 [% file = "path/to/template.html" %]
1580 [% BLOCK foo %]This is foo[% END %]
1583 Arguments may also be passed to the template:
1585 [% PROCESS "path/to/template.html" a = "An arg" b = "Another arg" %]
1587 Filenames must be relative to INCLUDE_PATH unless the ABSOLUTE
1588 or RELATIVE configuration items are set.
1592 Only available if the EVAL_PERL configuration item is true (default is false).
1593 Similar to the PERL directive, but you will need to append
1594 to the $output variable rather than just calling PRINT.
1598 Used to exit the innermost block or template and continue processing
1599 in the surrounding block or template.
1603 Used to set variables.
1605 [% SET a = 1 %][% a %] => "1"
1606 [% a = 1 %][% a %] => "1"
1607 [% b = 1 %][% SET a = b %][% a %] => "1"
1608 [% a = 1 %][% SET a %][% a %] => ""
1609 [% SET a = [1, 2, 3] %][% a.1 %] => "2"
1610 [% SET a = {b => 'c'} %][% a.b %] => "c"
1614 Used to exit the entire process method (out of all blocks and templates).
1615 No content will be processed beyond this point.
1619 Allow for SWITCH and CASE functionality.
1624 [% CASE "foo" %]a was foo
1625 [% CASE b %]a was bar
1626 [% CASE ["hi", "hello"] %]You said hi or hello
1627 [% CASE DEFAULT %]I don't know what you said
1632 You said hi or hello
1636 Change the type of enclosing braces used to delineate template tags. This
1637 remains in effect until the end of the enclosing block or template or until
1638 the next TAGS directive. Either a named set of tags must be supplied, or
1639 two tags themselves must be supplied.
1645 The named tags are (duplicated from TT):
1647 template => ['[%', '%]'], # default
1648 metatext => ['%%', '%%'], # Text::MetaText
1649 star => ['[*', '*]'], # TT alternate
1650 php => ['<?', '?>'], # PHP
1651 asp => ['<%', '%>'], # ASP
1652 mason => ['<%', '>' ], # HTML::Mason
1653 html => ['<!--', '-->'], # HTML comments
1657 Allows for throwing an exception. If the exception is not caught
1658 via the TRY DIRECTIVE, the template will abort processing of the directive.
1660 [% THROW mytypes.sometime 'Something happened' arg1 => val1 %]
1662 See the TRY directive for examples of usage.
1666 The TRY block directive will catch exceptions that are thrown
1667 while processing its block (It cannot catch parse errors unless
1668 they are in included files or evaltt'ed strings. The TRY block
1669 will then look for a CATCH block that will be processed. While
1670 it is being processed, the "error" variable will be set with the thrown
1671 exception as the value. After the TRY block - the FINAL
1672 block will be ran whether or not an error was thrown (unless a CATCH
1673 block throws an error).
1675 Note: Parse errors cannot be caught unless they are in an eval FILTER, or are
1676 in a separate template being INCLUDEd or PROCESSed.
1679 Nothing bad happened.
1683 This section runs no matter what happens.
1688 Nothing bad happened.
1689 This section runs no matter what happens.
1694 [% THROW "Something happened" %]
1697 Error.type: [% error.type %]
1698 Error.info: [% error.info %]
1700 This section runs no matter what happens.
1705 Error: undef error - Something happened
1707 Error.info: Something happened
1708 This section runs no matter what happens.
1710 You can give the error a type and more information including named arguments.
1711 This information replaces the "info" property of the exception.
1714 [% THROW foo.bar "Something happened" "grrrr" foo => 'bar' %]
1717 Error.type: [% error.type %]
1718 Error.info: [% error.info %]
1719 Error.info.0: [% error.info.0 %]
1720 Error.info.1: [% error.info.1 %]
1721 Error.info.args.0: [% error.info.args.0 %]
1722 Error.info.foo: [% error.info.foo %]
1725 Would print something like:
1727 Error: foo.bar error - HASH(0x82a395c)
1729 Error.info: HASH(0x82a395c)
1730 Error.info.0: Something happened
1732 Error.info.args.0: Something happened
1735 You can also give the CATCH block a type to catch. And you
1736 can nest TRY blocks. If types are specified, CET will try and
1737 find the closest matching type. Also, an error object can
1738 be re-thrown using $error as the argument to THROW.
1742 [% THROW foo.bar "Something happened" %]
1746 Caught default - but rethrew.
1754 Caught anything else.
1759 Caught default - but rethrew.
1765 Same as IF but condition is negated.
1767 [% UNLESS 0 %]hi[% END %] => hi
1769 Can also be a post operative directive.
1773 Allows for loading a Template::Toolkit style plugin.
1775 [% USE iter = Iterator(['foo', 'bar']) %]
1776 [%~ iter.get_first %]
1784 Note that it is possible to send arguments to the new object
1785 constructor. It is also possible to omit the variable name being
1786 assigned. In that case the name of the plugin becomes the variable.
1788 [% USE Iterator(['foo', 'bar', 'baz']) %]
1789 [%~ Iterator.get_first %]
1797 Plugins that are loaded are looked up for in the namespace listed in
1798 the PLUGIN_BASE directive which defaults to Template::Plugin. So in
1799 the previous example, if Template::Toolkit was installed, the iter
1800 object would loaded by the class Template::Plugin::Iterator. In CET,
1801 an effective way to disable plugins is to set the PLUGIN_BASE to a
1802 non-existent base such as "_" (In TT it will still fall back to look
1803 in Template::Plugin).
1805 Note: The iterator plugin will fall back and use
1806 CGI::Ex::Template::Iterator if Template::Toolkit is not installed. No
1807 other plugins come installed with CGI::Ex::Template.
1809 The names of the Plugin being loaded from PLUGIN_BASE are case
1810 insensitive. However, using case insensitive names is bad as it
1811 requires scanning the @INC directories for any module matching the
1812 PLUGIN_BASE and caching the result (OK - not that bad).
1814 If the plugin is not found and the LOAD_PERL directive is set, then
1815 CET will try and load a module by that name (note: this type of lookup
1816 is case sensitive and will not scan the @INC dirs for a matching
1819 # The LOAD_PERL directive should be set to 1
1820 [% USE cet = CGI::Ex::Template %]
1821 [%~ cet.dump_parse('2 * 3').replace('\s+', ' ') %]
1825 $VAR1 = [ \[ '*', '2', '3' ], 0 ];
1827 See the PLUGIN_BASE, and PLUGINS configuration items.
1829 See the documentation for Template::Manual::Plugins.
1833 Will process a block of code while a condition is true.
1849 [% WHILE (i = i - 1) %]
1859 Note that (f = f - 1) is a valid expression that returns the value
1860 of the assignment. The parenthesis are not optional.
1862 WHILE has a built in limit of 1000 iterations. This is controlled by the
1863 global variable $WHILE_MAX in CGI::Ex::Template.
1865 WHILE may also be used as a post operative directive.
1867 [% "$i" WHILE (i = i + 1) < 7 %] => 123456
1871 Block directive. Processes contents of its block and then passes them
1872 in the [% content %] variable to the block or filename listed in the
1876 My content to be processed.[% a = 2 %]
1888 My content to be processed.
1891 The WRAPPER directive may also be used as a post directive.
1893 [% BLOCK baz %]([% content %])[% END -%]
1894 [% "foobar" WRAPPER baz %]
1906 The following operators are available in CGI::Ex::Template. Except
1907 where noted these are the same operators available in TT. They are
1908 listed in the order of their precedence (the higher the precedence the
1915 The dot operator. Allows for accessing sub-members, methods, or
1916 virtual methods of nested data structures.
1918 my $obj->process(\$content, {a => {b => [0, {c => [34, 57]}]}}, \$output);
1920 [% a.b.1.c.0 %] => 34
1922 Note: on access to hashrefs, any hash keys that match the sub key name
1923 will be used before a virtual method of the same name. For example if
1924 a passed hash contained pair with a keyname "defined" and a value of
1925 "2", then any calls to hash.defined(another_keyname) would always
1926 return 2 rather than using the vmethod named "defined." To get around
1927 this limitation use the "|" operator (listed next). Also - on objects
1928 the "." will always try and call the method by that name. To always
1929 call the vmethod - use "|".
1933 The pipe operator. Similar to the dot operator. Allows for
1934 explicit calling of virtual methods and filters (filters are "merged"
1935 with virtual methods in CGI::Ex::Template and TT3) when accessing
1936 hashrefs and objects. See the note for the "." operator.
1938 The pipe character is similar to TT2 in that it can be used in place
1939 of a directive as an alias for FILTER. It similar to TT3 in that it
1940 can be used for virtual method access. This duality is one source of
1941 difference between CGI::Ex::Template and TT2 compatibility. Templates
1942 that have directives that end with a variable name that then use the
1943 "|" directive to apply a filter will be broken as the "|" will be
1944 applied to the variable name.
1946 The following two cases will do the same thing.
1950 [% foo FILTER html %]
1952 Though they do the same thing, internally, foo|html is stored as a
1953 single variable while "foo FILTER html" is stored as the variable foo
1954 which is then passed to the FILTER html.
1956 A TT2 sample that would break in CGI::Ex::Template or TT3 is:
1958 [% PROCESS foo a = b | html %]
1960 Under TT2 the content returned by "PROCESS foo a = b" would all be
1961 passed to the html filter. Under CGI::Ex::Template and TT3, b would
1962 be passed to the html filter before assigning it to the variable "a"
1963 before the template foo was processed.
1965 A simple fix is to do any of the following:
1967 [% PROCESS foo a = b FILTER html %]
1969 [% | html %][% PROCESS foo a = b %][% END %]
1971 [% FILTER html %][% PROCESS foo a = b %][% END %]
1973 This shouldn't be too much hardship and offers the great return of disambiguating
1974 virtual method access.
1978 Pre and post increment and decrement. My be used as either a prefix
1979 or postfix operator.
1981 [% ++a %][% ++a %] => 12
1983 [% a++ %][% a++ %] => 01
1985 [% --a %][% --a %] => -1-2
1987 [% a-- %][% a-- %] => 0-1
1991 Right associative binary. X raised to the Y power. This isn't available in TT 2.15.
1997 Prefix not. Negation of the value.
2001 Prefix minus. Returns the value multiplied by -1.
2003 [% a = 1 ; b = -a ; b %] => -1
2007 Left associative binary. Multiplication.
2011 Left associative binary. Division. Note that / is floating point division, but div and
2012 DIV are integer division.
2019 Left associative binary. Modulus.
2025 Left associative binary. Addition.
2029 Left associative binary. Minus.
2033 Left associative binary. String concatenation.
2035 [% "a" ~ "b" %] => ab
2037 =item C<< < > <= >= >>
2039 Non associative binary. Numerical comparators.
2041 =item C<lt gt le ge>
2043 Non associative binary. String comparators.
2047 Non associative binary. Equality test. TT chose to use Perl's eq for both operators.
2048 There is no test for numeric equality.
2052 Non associative binary. Non-equality test. TT chose to use Perl's ne for both
2053 operators. There is no test for numeric non-equality.
2057 Left associative binary. And. All values must be true. If all values are true, the last
2058 value is returned as the truth value.
2060 [% 2 && 3 && 4 %] => 4
2064 Right associative binary. Or. The first true value is returned.
2066 [% 0 || '' || 7 %] => 7
2068 Note: perl is left associative on this operator - but it doesn't matter because
2069 || has its own precedence level. Setting it to right allows for CET to short
2070 circuit earlier in the expression optree (left is (((1,2), 3), 4) while right
2071 is (1, (2, (3, 4))).
2075 Non associative binary. Range creator. Returns an arrayref containing the values
2076 between and including the first and last arguments.
2078 [% t = [1 .. 5] %] => variable t contains an array with 1,2,3,4, and 5
2080 It is possible to place multiple ranges in the same [] constructor. This is not available in TT.
2082 [% t = [1..3, 6..8] %] => variable t contains an array with 1,2,3,6,7,8
2084 The .. operator is the only operator that returns a list of items.
2088 Ternary - right associative. Can be nested with other ?: pairs.
2090 [% 1 ? 2 : 3 %] => 2
2091 [% 0 ? 2 : 3 %] => 3
2093 =item C<*= += -= /= **= %= ~=>
2095 Self-modifying assignment - right associative. Sets the left hand side
2096 to the operation of the left hand side and right (clear as mud).
2097 In order to not conflict with SET, FOREACH and other operations, this
2098 operator is only available in parenthesis.
2100 [% a = 2 %][% a += 3 %] --- [% a %] => --- 5 # is was handled by SET
2101 [% a = 2 %][% (a += 3) %] --- [% a %] => 5 --- 5
2105 Assignment - right associative. Sets the left-hand side to the value of the righthand side. In order
2106 to not conflict with SET, FOREACH and other operations, this operator is only
2107 available in parenthesis. Returns the value of the righthand side.
2109 [% a = 1 %] --- [% a %] => --- 1 # is was handled by SET
2110 [% (a = 1) %] --- [% a %] => 1 --- 1
2114 Prefix. Lower precedence version of the '!' operator.
2118 Left associative. Lower precedence version of the '&&' operator.
2122 Right associative. Lower precedence version of the '||' operator.
2126 This operator is not used in TT. It is used internally
2127 by CGI::Ex::Template to delay the creation of a hash until the
2128 execution of the compiled template.
2132 This operator is not used in TT. It is used internally
2133 by CGI::Ex::Template to delay the creation of an array until the
2134 execution of the compiled template.
2141 Chomping refers to the handling of whitespace immediately before and
2142 immediately after template tags. By default, nothing happens to this
2143 whitespace. Modifiers can be placed just inside the opening and just
2144 before the closing tags to control this behavior.
2146 Additionally, the PRE_CHOMP and POST_CHOMP configuration variables can
2147 be set and will globally control all chomping behavior for tags that
2148 do not have their own chomp modifier. PRE_CHOMP and POST_CHOMP can
2149 be set to any of the following values:
2151 none: 0 + Template::Constants::CHOMP_NONE
2152 one: 1 - Template::Constants::CHOMP_ONE
2153 collapse: 2 = Template::Constants::CHOMP_COLLAPSE
2154 greedy: 3 ~ Template::Constants::CHOMP_GREEDY
2160 Don't do any chomping. The "+" sign is used to indicate CHOMP_NONE.
2176 =item CHOMP_ONE (formerly known as CHOMP_ALL)
2178 Delete any whitespace up to the adjacent newline. The "-" is used to indicate CHOMP_ONE.
2192 =item CHOMP_COLLAPSE
2194 Collapse adjacent whitespace to a single space. The "=" is used to indicate CHOMP_COLLAPSE.
2208 Remove all adjacent whitespace. The "~" is used to indicate CHOMP_GREEDY.
2220 =head1 CONFIGURATION
2222 The following TT2 configuration variables are supported (in
2223 alphabetical order). Note: for further discussion you can refer to
2224 the TT config documentation.
2226 These variables should be passed to the "new" constructor.
2228 my $obj = CGI::Ex::Template->new(
2229 VARIABLES => \%hash_of_variables,
2241 Boolean. Default false. Are absolute paths allowed for included files.
2245 Boolean. Default 1. Clear blocks that were set during the process method.
2249 A hashref of blocks that can be used by the process method.
2252 block_1 => sub { ... }, # coderef that returns a block
2253 block_2 => 'A String', # simple string
2256 Note that a Template::Document cannot be supplied as a value (TT
2257 supports this). However, it is possible to supply a value that is
2258 equal to the hashref returned by the load_parsed_tree method.
2262 Number of compiled templates to keep in memory. Default undef.
2263 Undefined means to allow all templates to cache. A value of 0 will
2264 force no caching. The cache mechanism will clear templates that have
2265 not been used recently.
2269 Base directory to store compiled templates. Default undef. Compiled
2270 templates will only be stored if one of COMPILE_DIR and COMPILE_EXT is
2275 Extension to add to stored compiled template filenames. Default undef.
2279 Hashref. Used to define variables that will be "folded" into the
2280 compiled template. Variables defined here cannot be overridden.
2282 CONSTANTS => {my_constant => 42},
2284 A template containing:
2286 [% constants.my_constant %]
2288 Will have the value 42 compiled in.
2290 Constants defined in this way can be chained as in [%
2291 constant.foo.bar.baz %].
2293 =item CONSTANT_NAMESPACE
2295 Allow for setting the top level of values passed in CONSTANTS. Default
2296 value is 'constants'.
2300 Takes a list of constants |'ed together which enables different
2301 debugging modes. Alternately the lowercase names may be used
2302 (multiple values joined by a ",").
2304 The only supported TT values are:
2305 DEBUG_UNDEF (2) - debug when an undefined value is used.
2306 DEBUG_DIRS (8) - debug when a directive is used.
2307 DEBUG_ALL (2047) - turn on all debugging.
2309 Either of the following would turn on undef and directive debugging:
2311 DEBUG => 'undef, dirs', # preferred
2313 DEBUG => DEBUG_UNDEF | DEBUG_DIRS, # constants from Template::Constants
2317 Change the format of messages inserted when DEBUG has DEBUG_DIRS set on.
2318 This essentially the same thing as setting the format using the DEBUG
2323 The name of a default template file to use if the passed one is not found.
2327 String to use to split INCLUDE_PATH with. Default is :. It is more
2328 straight forward to just send INCLUDE_PATH an arrayref of paths.
2332 Set a string to use as the closing delimiter for TT. Default is "%]".
2336 Boolean. Default false. If set to a true value, PERL and RAWPERL blocks
2337 will be allowed to run. This is a potential security hole, as arbitrary
2338 perl can be included in the template. If Template::Toolkit is installed,
2339 a true EVAL_PERL value also allows the perl and evalperl filters to be used.
2343 Allow for passing in TT style filters.
2346 filter1 => sub { my $str = shift; $s =~ s/./1/gs; $s },
2347 filter2 => [sub { my $str = shift; $s =~ s/./2/gs; $s }, 0],
2348 filter3 => [sub { my ($context, @args) = @_; return sub { my $s = shift; $s =~ s/./3/gs; $s } }, 1],
2353 1([% a | filter1 %])
2354 2([% a | filter2 %])
2355 3([% a | filter3 %])
2358 my $obj = CGI::Ex::Template->new(FILTERS => $filters);
2359 $obj->process(\$str) || die $obj->error;
2367 Filters passed in as an arrayref should contain a coderef and a value
2368 indicating if they are dynamic or static (true meaning dynamic). The
2369 dynamic filters are passed the pseudo context object and any arguments
2370 and should return a coderef that will be called as the filter. The filter
2371 coderef is then passed the string.
2375 A string or an arrayref or coderef that returns an arrayref that
2376 contains directories to look for files included by processed
2381 Non-TT item. Same as INCLUDE_PATH but only takes an arrayref. If not specified
2382 then INCLUDE_PATH is turned into an arrayref and stored in INCLUDE_PATHS.
2383 Overrides INCLUDE_PATH.
2387 Boolean. Specifies whether variables in text portions of the template will be
2388 interpolated. For example, the $variable and ${var.value} would be substituted
2389 with the appropriate values from the variable cache (if INTERPOLATE is on).
2391 [% IF 1 %]The variable $variable had a value ${var.value}[% END %]
2396 Indicates if the USE directive can fall back and try and load a perl module
2397 if the indicated module was not found in the PLUGIN_BASE path. See the
2402 No Template::Namespace::Constants support. Hashref of hashrefs representing
2403 constants that will be folded into the template at compile time.
2405 CGI::Ex::Template->new(NAMESPACE => {constants => {
2411 CGI::Ex::Template->new(CONSTANTS => {
2415 Any number of hashes can be added to the NAMESPACE hash.
2419 Alternate way of passing in the output location for processed templates.
2420 If process is not passed an output argument, it will look for this value.
2422 See the process method for a listing of possible values.
2426 Base path for files written out via the process method or via the redirect
2427 and file filters. See the redirect virtual method and the process method
2428 for more information.
2432 A hashref of mappings of plugin modules.
2435 Iterator => 'Template::Plugin::Iterator',
2439 See the USE directive for more information.
2443 Default value is Template::Plugin. The base module namespace
2444 that template plugins will be looked for. See the USE directive
2445 for more information.
2449 Set the type of chomping at the ending of a tag.
2450 See the section on chomping for more information.
2454 A list of templates to be processed and appended to the content
2455 after the main template. During this processing the "template"
2456 namespace will contain the name of the main file being processed.
2458 This is useful for adding a global footer to all templates.
2462 Set the type of chomping at the beginning of a tag.
2463 See the section on chomping for more information.
2467 Same as the VARIABLES configuration item.
2471 A list of templates to be processed before and pre-pended to the content
2472 before the main template. During this processing the "template"
2473 namespace will contain the name of the main file being processed.
2475 This is useful for adding a global header to all templates.
2479 Specify a file to use as the template rather than the one passed in
2480 to the ->process method.
2484 Boolean. Default false. Indicates that INCLUDED or PROCESSED files
2485 can refer to each other in a circular manner. Be careful about recursion.
2489 Boolean. Default false. If true, allows filenames to be specified
2490 that are relative to the currently running process.
2494 Set a string to use as the opening delimiter for TT. Default is "[%".
2498 Allow for setting the type of tag delimiters to use for parsing the TT.
2499 See the TAGS directive for a listing of the available types.
2503 Remove leading and trailing whitespace from blocks and templates.
2504 This operation is performed after all enclosed template tags have
2509 This is not a TT configuration option. This option expects to be a code
2510 ref that will be called if a variable is undefined during a call to play_expr.
2511 It is passed the variable identity array as a single argument. This
2512 is most similar to the "undefined" method of Template::Stash. It allows
2513 for the "auto-defining" of a variable for use in the template. It is
2514 suggested that UNDEFINED_GET be used instead as UNDEFINED_ANY is a little
2515 to general in defining variables.
2517 You can also sub class the module and override the undefined_any method.
2521 This is not a TT configuration option. This option expects to be a code
2522 ref that will be called if a variable is undefined during a call to GET.
2523 It is passed the variable identity array as a single argument. This is more useful
2524 than UNDEFINED_ANY in that it is only called during a GET directive
2525 rather than in embedded expressions (such as [% a || b || c %]).
2527 You can also sub class the module and override the undefined_get method.
2531 A hashref of variables to initialize the template stash with. These
2532 variables are available for use in any of the executed templates.
2533 See the section on VARIABLES for the types of information that can be passed in.
2539 =head1 UNSUPPORTED TT CONFIGURATION
2545 This will not be supported. You will have to use the full case directive names.
2546 (It was in the beta code but was removed prior to release).
2550 This will be supported - just not done yet.
2554 This will be supported - just not done yet.
2558 This will not be supported.
2560 =item LOAD_TEMPLATES
2562 CGI::Ex::Template has its own mechanism for loading and storing
2563 compiled templates. TT would use a Template::Provider that would
2564 return a Template::Document. The closest thing in CGI::Ex::Template
2565 is the load_parsed_template method. There is no immediate plan to
2566 support the TT behavior.
2570 CGI::Ex::Template uses its own mechanism for loading plugins. TT
2571 would use a Template::Plugins object to load plugins requested via the
2572 USE directive. The functionality for doing this in CGI::Ex::Template
2573 is contained in the list_plugins method and the play_USE method. There
2574 is no immediate plan to support the TT behavior.
2576 Full support is offered for the PLUGINS and LOAD_PERL configuration items.
2578 Also note that CGI::Ex::Template only natively supports the Iterator plugin.
2579 Any of the other plugins requested will need to provided by installing
2580 Template::Toolkit or the appropriate plugin module.
2584 CGI::Ex::Template uses its own mechanism for loading filters. TT
2585 would use the Template::Filters object to load filters requested via the
2586 FILTER directive. The functionality for doing this in CGI::Ex::Template
2587 is contained in the list_filters method and the play_expr method.
2589 Full support is offered for the FILTERS configuration item.
2593 This option is used by the LOAD_TEMPLATES and LOAD_PLUGINS options and
2594 is not applicable in CGI::Ex::Template.
2598 CGI::Ex::Template has no concept of service (theoretically the CGI::Ex::Template
2603 CGI::Ex::Template provides its own pseudo context object to plugins,
2604 filters, and perl blocks. The CGI::Ex::Template model doesn't really
2605 allow for a separate context. CGI::Ex::Template IS the context.
2609 CGI::Ex::Template manages its own stash of variables. A pseudo stash
2610 object is available via the pseudo context object for use in plugins,
2611 filters, and perl blocks.
2615 CGI::Ex::Template has its own built in parser. The closest similarity is
2616 the parse_tree method. The output of parse_tree is an optree that is
2617 later run by execute_tree.
2621 CGI::Ex::Template maintains its own grammar. The grammar is defined
2622 in the parse_tree method and the callbacks listed in the global
2623 $DIRECTIVES hashref.
2628 =head1 VARIABLE PARSE TREE
2630 CGI::Ex::Template parses templates into an tree of operations. Even
2631 variable access is parsed into a tree. This is done in a manner
2632 somewhat similar to the way that TT operates except that nested
2633 variables such as foo.bar|baz contain the '.' or '|' in between each
2634 name level. Operators are parsed and stored as part of the variable (it
2635 may be more appropriate to say we are parsing a term or an expression).
2637 The following table shows a variable or expression and the corresponding parsed tree
2638 (this is what the parse_expr method would return).
2642 one.two [ 'one', 0, '.', 'two', 0 ]
2643 one|two [ 'one', 0, '|', 'two', 0 ]
2644 one.$two [ 'one', 0, '.', ['two', 0 ], 0 ]
2645 one(two) [ 'one', [ ['two', 0] ] ]
2646 one.${two().three} [ 'one', 0, '.', ['two', [], '.', 'three', 0], 0]
2649 "one"|length [ \"one", 0, '|', 'length', 0 ]
2650 "one $a two" [ \ [ '~', 'one ', ['a', 0], ' two' ], 0 ]
2651 [0, 1, 2] [ \ [ 'array', 0, 1, 2 ], 0 ]
2652 [0, 1, 2].size [ \ [ 'array', 0, 1, 2 ], 0, '.', 'size', 0 ]
2653 ['a', a, $a ] [ \ [ 'array', 'a', ['a', 0], [['a', 0], 0] ], 0]
2654 {a => 'b'} [ \ [ 'hash', 'a', 'b' ], 0 ]
2655 {a => 'b'}.size [ \ [ 'hash', 'a', 'b' ], 0, '.', 'size', 0 ]
2656 {$a => b} [ \ [ 'hash', ['a', 0], ['b', 0] ], 0 ]
2657 1 + 2 [ \ [ '+', 1, 2 ], 0]
2658 a + b [ \ [ '+', ['a', 0], ['b', 0] ], 0 ]
2659 a * (b + c) [ \ [ '*', ['a', 0], [ \ ['+', ['b', 0], ['c', 0]], 0 ]], 0 ]
2660 (a + b) [ \ [ '+', ['a', 0], ['b', 0] ]], 0 ]
2661 (a + b) * c [ \ [ '*', [ \ [ '+', ['a', 0], ['b', 0] ], 0 ], ['c', 0] ], 0 ]
2662 a ? b : c [ \ [ '?', ['a', 0], ['b', 0], ['c', 0] ], 0 ]
2663 a || b || c [ \ [ '||', ['a', 0], [ \ [ '||', ['b', 0], ['c', 0] ], 0 ] ], 0 ]
2664 ! a [ \ [ '!', ['a', 0] ], 0 ]
2666 Some notes on the parsing.
2668 Operators are parsed as part of the variable and become part of the variable tree.
2670 Operators are stored in the variable tree using a reference to the arrayref - which
2671 allows for quickly descending the parsed variable tree and determining that the next
2672 node is an operator.
2674 Parenthesis () can be used at any point in an expression to disambiguate precedence.
2676 "Variables" that appear to be literal strings or literal numbers
2677 are returned as the literal (no operator tree).
2679 The following perl can be typed at the command line to view the parsed variable tree:
2681 perl -e 'use CGI::Ex::Template; print CGI::Ex::Template::dump_parse("foo.bar + 2")."\n"'
2683 Also the following can be included in a template to view the output in a template:
2685 [% USE cet = CGI::Ex::Template %]
2686 [%~ cet.dump_parse('foo.bar + 2').replace('\s+', ' ') %]
2689 =head1 SEMI PUBLIC METHODS
2691 The following list of methods are other interesting methods of CET that
2692 may be re-implemented by subclasses of CET.
2698 This method allows for returning a Data::Dumper dump of a parsed variable. It is mainly used for testing.
2702 Creates an exception object blessed into the package listed in
2703 $CGI::Ex::Template::PACKAGE_EXCEPTION.
2705 =item C<execute_tree>
2707 Executes a parsed tree (returned from parse_tree)
2711 Turns a variable identity array into the parsed variable. This
2712 method is also responsible for playing operators and running virtual methods
2713 and filters. The method could more accurately be called play_expression.
2715 =item C<include_filename>
2717 Takes a file path, and resolves it into the full filename using
2718 paths from INCLUDE_PATH or INCLUDE_PATHS.
2722 Resolves the file passed, and then returns its contents.
2724 =item C<list_filters>
2726 Dynamically loads the filters list from Template::Filters when a filter
2727 is used that is not natively implemented in CET.
2729 =item C<list_plugins>
2731 Returns an arrayref of modules that are under a base Namespace.
2733 my @modules = @{ $self->list_plugins({base => 'Template::Plugins'}) }:
2735 =item C<load_parsed_tree>
2737 Given a filename or a string reference will return a parsed document
2738 hash that contains the parsed tree.
2740 my $doc = $self->load_parsed_tree($file) || $self->throw('undef', "Zero length content");
2744 Allow for the multitudinous ways that TT parses arguments. This allows
2745 for positional as well as named arguments. Named arguments can be separated with a "=" or "=>",
2746 and positional arguments should be separated by " " or ",". This only returns an array
2747 of parsed variables. To get the actual values, you must call play_expr on each value.
2751 Used by load_parsed_tree. This is the main grammar engine of the program. It
2752 uses method in the $DIRECTIVES hashref to parse different DIRECTIVE TYPES.
2756 Used to parse a variable, an expression, a literal string, or a number. It
2757 returns a parsed variable tree. Samples of parsed variables can be found in the VARIABLE PARSE TREE
2760 =item C<set_variable>
2762 Used to set a variable. Expects a variable identity array and the value to set. It
2763 will autovifiy as necessary.
2767 Creates an exception object from the arguments and dies.
2769 =item C<undefined_any>
2771 Called during play_expr if a value is returned that is undefined. This could
2772 be used to magically create variables on the fly. This is similar to Template::Stash::undefined.
2773 It is suggested that undefined_get be used instead. Default behavior returns undef. You
2774 may also pass a coderef via the UNDEFINED_ANY configuration variable. Also, you can try using
2775 the DEBUG => 'undef', configuration option which will throw an error on undefined variables.
2777 =item C<undefined_get>
2779 Called when a variable is undefined during a GET directive. This is useful to
2780 see if a value that is about to get inserted into the text is undefined. undefined_any is a little
2781 too general for most cases. Also, you may pass a coderef via the UNDEFINED_GET configuration variable.
2786 =head1 OTHER UTILITY METHODS
2788 The following is a brief list of other methods used by CET. Generally, these
2789 shouldn't be overwritten by subclasses.
2793 =item C<apply_precedence>
2795 Allows for parsed operator array to be translated to a tree based
2796 upon operator precedence.
2800 Used to create a "pseudo" context object that allows for portability
2801 of TT plugins, filters, and perl blocks that need a context object.
2805 TT2 Holdover that is used once for binmode setting during a TT2 test.
2809 Used to get debug info on a directive if DEBUG_DIRS is set.
2813 Methods by these names implement filters that are more than one line.
2815 =item C<get_line_number_by_index>
2817 Used to turn string index position into line number
2819 =item C<interpolate_node>
2821 Used for parsing text nodes for dollar variables when interpolate is on.
2825 Methods by these names are used by parse_tree to parse the template. These are the grammar.
2829 Methods by these names are used by execute_tree to execute the parsed tree.
2831 =item C<play_operator>
2833 Used to execute any found operators
2837 Called by process and the PROCESS, INCLUDE and other directives.
2841 Reads contents of passed filename - throws file exception on error.
2843 =item C<split_paths>
2845 Used to split INCLUDE_PATH or other directives if an arrayref is not passed.
2849 Return a reference to the current stash of variables. This is currently only used
2850 by the pseudo context object and may disappear at some point.
2854 Methods by these names implement virtual methods that are more than one line.
2858 Used to create a weak reference to self to avoid circular references. (this
2859 is needed by macros)
2866 Paul Seamons <paul at seamons dot com>