1 package Template::Simple;
7 use Scalar::Util qw( reftype ) ;
12 our $VERSION = '0.03';
17 post_delim => qr/%\]/,
21 include_paths => [ qw( templates ) ],
26 my( $class, %opts ) = @_ ;
28 my $self = bless {}, $class ;
30 # get all the options or defaults into the object
32 while( my( $name, $default ) = each %opt_defaults ) {
34 $self->{$name} = defined( $opts{$name} ) ?
35 $opts{$name} : $default ;
38 # make up the regexes to parse the markup from templates
40 # this matches scalar markups and grabs the name
42 $self->{scalar_re} = qr{
44 \s* # optional leading whitespace
45 (\w+?) # grab scalar name
46 \s* # optional trailing whitespace
48 }xi ; # case insensitive
50 #print "RE <$self->{scalar_re}>\n" ;
52 # this grabs the body of a chunk in either greedy or non-greedy modes
54 my $chunk_body = $self->{greedy_chunk} ? qr/.+/s : qr/.+?/s ;
56 # this matches a marked chunk and grabs its name and text body
58 $self->{chunk_re} = qr{
60 \s* # optional leading whitespace
61 START # required START token
62 \s+ # required whitespace
63 (\w+?) # grab the chunk name
64 \s* # optional trailing whitespace
66 ($chunk_body) # grab the chunk body
68 \s* # optional leading whitespace
69 END # required END token
70 \s+ # required whitespace
71 \1 # match the grabbed chunk name
72 \s* # optional trailing whitespace
74 }xi ; # case insensitive
76 #print "RE <$self->{chunk_re}>\n" ;
78 # this matches a include markup and grabs its template name
80 $self->{include_re} = qr{
82 \s* # optional leading whitespace
83 INCLUDE # required INCLUDE token
84 \s+ # required whitespace
85 (\w+?) # grab the included template name
86 \s* # optional trailing whitespace
88 }xi ; # case insensitive
90 # load in any templates
92 $self->add_templates( $opts{templates} ) ;
101 my( $self, $template, $data ) = @_ ;
103 # make a copy if a scalar ref is passed as the template text is
106 my $tmpl_ref = ref $template eq 'SCALAR' ? $template : \$template ;
108 my $rendered = $self->_render_includes( $tmpl_ref ) ;
110 #print "INC EXP <$rendered>\n" ;
113 $self->_render_chunk( $rendered, $data ) ;
116 croak "Template::Simple $@" if $@ ;
121 sub _render_includes {
123 my( $self, $tmpl_ref ) = @_ ;
125 # make a copy of the initial template so we can render it.
127 my $rendered = ${$tmpl_ref} ;
129 # loop until we can render no more include markups
132 s{$self->{include_re}}
133 { ${ $self->_get_template($1) }
141 HASH => \&_render_hash,
142 ARRAY => \&_render_array,
143 CODE => \&_render_code,
144 # if no ref then data is a scalar so replace the template with just the data
145 '' => sub { \$_[2] },
151 my( $self, $tmpl_ref, $data ) = @_ ;
153 #print "T ref [$tmpl_ref] [$$tmpl_ref]\n" ;
154 #print "CHUNK ref [$tmpl_ref] TMPL\n<$$tmpl_ref>\n" ;
156 #print Dumper $data ;
158 return \'' unless defined $data ;
160 # now render this chunk based on the type of data
162 my $renderer = $renderers{reftype $data || ''} ;
164 #print "EXP $renderer\nREF ", reftype $data, "\n" ;
166 die "unknown template data type '$data'\n" unless defined $renderer ;
168 return $self->$renderer( $tmpl_ref, $data ) ;
173 my( $self, $tmpl_ref, $href ) = @_ ;
175 return $tmpl_ref unless keys %{$href} ;
177 # we need a local copy of the template to render
179 my $rendered = ${$tmpl_ref} ;
182 # recursively render all top level chunks in this chunk
184 $rendered =~ s{$self->{chunk_re}}
186 # print "CHUNK $1\nBODY\n----\n<$2>\n\n------\n" ;
187 ${ $self->_render_chunk( \"$2", $href->{$1} ) }
192 #print "HREF: ", Dumper $href ;
194 $rendered =~ s{$self->{scalar_re}}
196 # print "SCALAR $1 VAL $href->{$1}\n" ;
197 defined $href->{$1} ? $href->{$1} : ''
200 #print "HASH REND3\n<$rendered>\n" ;
207 my( $self, $tmpl_ref, $aref ) = @_ ;
209 # render this $tmpl_ref for each element of the aref and join them
213 #print "AREF: ", Dumper $aref ;
215 $rendered .= ${$self->_render_chunk( $tmpl_ref, $_ )} for @{$aref} ;
222 my( $self, $tmpl_ref, $cref ) = @_ ;
224 my $rendered = $cref->( $tmpl_ref ) ;
226 die <<DIE if ref $rendered ne 'SCALAR' ;
227 data callback to code didn't return a scalar or scalar reference
235 my( $self, $tmpls ) = @_ ;
237 #print Dumper $tmpls ;
238 return unless defined $tmpls ;
240 ref $tmpls eq 'HASH' or croak "templates argument is not a hash ref" ;
242 @{ $self->{templates}}{ keys %{$tmpls} } =
243 map ref $_ eq 'SCALAR' ? \"${$_}" : \"$_", values %{$tmpls} ;
245 #print Dumper $self->{templates} ;
250 sub delete_templates {
252 my( $self, @names ) = @_ ;
254 @names = keys %{$self->{templates}} unless @names ;
256 delete @{$self->{templates}}{ @names } ;
258 delete @{$self->{template_paths}}{ @names } ;
265 my( $self, $tmpl_name ) = @_ ;
267 #print "INC $tmpl_name\n" ;
269 my $tmpls = $self->{templates} ;
271 # get the template from the cache and send it back if it was found there
273 my $template = $tmpls->{ $tmpl_name } ;
274 return $template if $template ;
276 # not found, so find, slurp in and cache the template
278 $template = $self->_find_template( $tmpl_name ) ;
279 $tmpls->{ $tmpl_name } = $template ;
286 my( $self, $tmpl_name ) = @_ ;
288 foreach my $dir ( @{$self->{include_paths}} ) {
290 my $tmpl_path = "$dir/$tmpl_name.tmpl" ;
292 #print "PATH: $tmpl_path\n" ;
293 next unless -r $tmpl_path ;
295 # cache the path to this template
297 $self->{template_paths}{$tmpl_name} = $tmpl_path ;
299 # slurp in the template file and return it as a scalar ref
301 return scalar read_file( $tmpl_path, scalar_ref => 1 ) ;
305 can't find template '$tmpl_name' in '@{$self->{include_paths}}'
310 1; # End of Template::Simple
316 Template::Simple - A simple and fast template module
324 use Template::Simple;
326 my $tmpl = Template::Simple->new();
328 my $template = <<TMPL ;
331 [%first%] - [%second%]
338 date => 'Jan 1, 2008',
339 author => 'Me, myself and I',
343 first => 'row 1 value 1',
344 second => 'row 1 value 2',
347 first => 'row 2 value 1',
348 second => 'row 2 value 2',
352 modified => 'Aug 31, 2006',
356 my $rendered = $tmpl->render( $template, $data ) ;
360 Template::Simple has these goals:
364 =item * Support most common template operations
366 It can recursively include other templates, replace tokens (scalars),
367 recursively render nested chunks of text and render lists. By using
368 simple idioms you can get conditional renderings.
370 =item * Complete isolation of template from program code
372 This is very important as template design can be done by different
373 people than the program logic. It is rare that one person is well
374 skilled in both template design and also programming.
376 =item * Very simple template markup (only 4 markups)
378 The only markups are C<INCLUDE>, C<START>, C<END> and C<token>. See
381 =item * Easy to follow rendering rules
383 Rendering of templates and chunks is driven from a data tree. The type
384 of the data element used in an rendering controls how the rendering
385 happens. The data element can be a scalar or scalar reference or an
386 array, hash or code reference.
388 =item * Efficient template rendering
390 Rendering is very simple and uses Perl's regular expressions
391 efficiently. Because the markup is so simple less processing is needed
392 than many other templaters. Precompiling templates is not supported
393 yet but that optimization is on the TODO list.
395 =item * Easy user extensions
397 User code can be called during an rendering so you can do custom
398 renderings and plugins. Closures can be used so the code can have its
399 own private data for use in rendering its template chunk.
405 You create a Template::Simple by calling the class method new:
407 my $tmpl = Template::Simple->new() ;
409 All the arguments to C<new()> are key/value options that change how
410 the object will do renderings.
416 This option sets the string or regex that is the starting delimiter
417 for all markups. You can use a plain string or a qr// but you need to
418 escape (with \Q or \) any regex metachars if you want them to be plain
419 chars. The default is qr/\[%/.
421 my $tmpl = Template::Simple->new(
425 my $rendered = $tmpl->render( '<%FOO%]', 'bar' ) ;
429 This option sets the string or regex that is the ending delimiter
430 for all markups. You can use a plain string or a qr// but you need to
431 escape (with \Q or \) any regex metachars if you want them to be plain
432 chars. The default is qr/%]/.
434 my $tmpl = Template::Simple->new(
438 my $rendered = $tmpl->render( '[%FOO%>', 'bar' ) ;
442 This boolean option will cause the regex that grabs a chunk of text
443 between the C<START/END> markups to become greedy (.+). The default is
444 a not-greedy grab of the chunk text. (UNTESTED)
448 This option lets you load templates directly into the cache of the
449 Template::Simple object. This cache will be searched by the C<INCLUDE>
450 markup which will be replaced by the template if found. The option
451 value is a hash reference which has template names (the name in the
452 C<INCLUDE> markup) for keys and their template text as their
453 values. You can delete or clear templates from the object cache with
454 the C<delete_template> method.
457 my $tmpl = Template::Simple->new(
461 [%baz%] is a [%quux%]
464 [%user%] is not a [%fool%]
469 my $template = <<TMPL ;
473 my $rendered = $tmpl->render(
483 Template::Simple can also load C<INCLUDE> templates from files. This
484 option lets you set the directory paths to search for those
485 files. Note that the template name in the C<INCLUDE> markup has the
486 .tmpl suffix appended to it when searched for in one of these
487 paths. The loaded file is cached inside the Template::Simple object
488 along with any loaded by the C<templates> option.
496 This method is passed a template and a data tree and it renders it and
497 returns a reference to the resulting string. The template argument can
498 be a scalar or a scalar reference. The data tree argument can be any
499 value allowed by Template::Simple when rendering a template. It can
500 also be a blessed reference (Perl object) since
501 C<Scalar::Util::reftype> is used instead of C<ref> to determine the
504 Note that the author recommends against passing in an object as this
505 breaks encapsulation and forces your object to be (most likely) a
506 hash. It would be better to create a simple method that copies the
507 object contents to a hash reference and pass that. But current
508 templaters allow passing in objects so that is supported here as well.
510 my $rendered = $tmpl->render( $template, $data ) ;
514 This method adds templates to the object cache. It takes a list of template names and texts just like the C<templates> constructor option.
516 $tmpl->add_templates(
518 foo => \$foo_template,
519 bar => '[%include bar%]',
523 =head2 delete_templates
525 This method takes a list of template names and will delete them from
526 the template cache in the object. If you pass in an empty list then
527 all the templates will be deleted. This can be used when you know a
528 template file has been updated and you want to get it loaded back into
529 the cache. Note that you can delete templates that were loaded
530 directly (via the C<templates> constructor option or the
531 C<add_templates> method) or loaded from a file.
533 # this deletes only the foo and bar templates from the object cache
535 $tmpl->delete_templates( qw( foo bar ) ;
537 # this deletes all of templates from the object cache
539 $tmpl->delete_templates() ;
541 =head2 get_dependencies
543 This method render the only C<INCLUDE> markups of a template and it
544 returns a list of the file paths that were found and loaded. It is
545 meant to be used to build up a dependency list of included templates
546 for a main template. Typically this can be called from a script (see
547 TODO) that will do this for a set of main templates and will generate
548 Makefile dependencies for them. Then you can regenerate rendered
549 templates only when any of their included templates have changed. It
550 takes a single argument of a template.
552 UNKNOWN: will this require a clearing of the cache or will it do the
553 right thing on its own? or will it use the file path cache?
556 $tmpl->get_dependencies( '[%INCLUDE top_level%]' );
560 All the markups in Template::Simple use the same delimiters which are
561 C<[%> and C<%]>. You can change the delimiters with the C<pre_delim>
562 and C<post_delim> options in the C<new()> constructor.
566 A token is a single markup with a C<\w+> Perl word inside. The token
567 can have optional whitespace before and after it. A token is replaced
568 by a value looked up in a hash with the token as the key. The hash
569 lookup keeps the same case as parsed from the token markup.
573 Those will be replaced by C<$href->{foo}> and C<$href->{BAR}> assuming
574 C<$href> is the current data for this rendering. Tokens are only
575 parsed out during hash data rendering so see Hash Data for more.
579 Chunks are regions of text in a template that are marked off with a
580 start and end markers with the same name. A chunk start marker is
581 C<[%START name%]> and the end marker for that chunk is C<[%END
582 name%]>. C<name> is a C<\w+> Perl word which is the name of this
583 chunk. The whitespace between C<START/END> and C<name> is required and
584 there is optional whitespace before C<START/END> and after the
585 C<name>. C<START/END> are case insensitive but the C<name>'s case is
586 kept. C<name> must match in the C<START/END> pair and it used as a key
587 in a hash data rendering. Chunks are the primary way to markup
588 templates for structures (sets of tokens), nesting (hashes of hashes),
589 repeats (array references) and callbacks to user code. Chunks are only
590 parsed out during hash data rendering so see Hash Data for more.
592 The body of text between the C<START/END> markups is grabbed with a
593 C<.+?> regular expression with the /s option enabled so it will match
594 all characters. By default it will be a non-greedy grab but you can
595 change that in the constructor by enabling the C<greedy_chunk> option.
605 =head1 RENDERING RULES
607 Template::Simple has a short list of rendering rules and they are easy
608 to understand. There are two types of renderings, include rendering
609 and chunk rendering. In the C<render> method, the template is an
610 unnamed top level chunk of text and it first gets its C<INCLUDE>
611 markups rendered. The text then undergoes a chunk rendering and a
612 scalar reference to that rendered template is returned to the caller.
614 =head2 Include Rendering
616 Include rendering is performed one time on a top level template. When
617 it is done the template is ready for chunk rendering. Any markup of
618 the form C<[%INCLUDE name]%> will be replaced by the text found in the
619 template C<name>. The template name is looked up in the object's
620 template cache and if it is found there its text is used as the
623 If a template is not found in the cache, it will be searched for in
624 the list of directories in the C<include_paths> option. The file name
625 will be a directory in that list appended with the template name and
626 the C<.tmpl> suffix. The first template file found will be read in and
627 stored in the cache. Its path is also saved and those will be returned
628 in the C<get_dependencies> method. See the C<add_templates> and
629 C<delete_templates> methods and the C<include_paths> option.
631 Rendered include text can contain more C<INCLUDE> markups and they
632 will also be rendered. The include rendering phase ends where there
633 are no more C<INCLUDE> found.
635 =head2 Chunk Rendering
637 A chunk is the text found between C<START> and C<END> markups and it
638 gets its named from the C<START> markup. The top level template is
639 considered an unamed chunk and also gets chunk rendered.
641 The data for a chunk determines how it will be rendered. The data can
642 be a scalar or scalar reference or an array, hash or code
643 reference. Since chunks can contain nested chunks, rendering will
644 recurse down the data tree as it renders the chunks. Each of these
645 renderings are explained below. Also see the IDIOMS and BEST PRACTICES
646 section for examples and used of these renderings.
648 =head2 Scalar Data Rendering
650 If the current data for a chunk is a scalar or scalar reference, the
651 chunk's text in the templated is replaced by the scalar's value. This
652 can be used to overwrite one default section of text with from the
655 =head2 Code Data Rendering
657 If the current data for a chunk is a code reference (also called
658 anonymous sub) then the code reference is called and it is passed a
659 scalar reference to the that chunk's text. The code must return a
660 scalar or a scalar reference and its value replaces the chunk's text
661 in the template. If the code returns any other type of data it is a
662 fatal error. Code rendering is how you can do custom renderings and
663 plugins. A key idiom is to use closures as the data in code renderings
664 and keep the required outside data in the closure.
666 =head2 Array Data Rendering
668 If the current data for a chunk is an array reference do a full chunk
669 rendering for each value in the array. It will replace the original
670 chunk text with the joined list of rendered chunks. This is how you do
671 repeated sections in Template::Simple and why there is no need for any
672 loop markups. Note that this means that rendering a chunk with $data
673 and [ $data ] will do the exact same thing. A value of an empty array
674 C<[]> will cause the chunk to be replaced by the empty string.
676 =head2 Hash Data Rendering
678 If the current data for a chunk is a hash reference then two phases of
679 rendering happen, nested chunk rendering and token rendering. First
680 nested chunks are parsed of of this chunk along with their names. Each
681 parsed out chunk is rendered based on the value in the current hash
682 with the nested chunk's name as the key.
684 If a value is not found (undefined), then the nested chunk is replaced
685 by the empty string. Otherwise the nested chunk is rendered according
686 to the type of its data (see chunk rendering) and it is replaced by
689 Chunk name and token lookup in the hash data is case sensitive (see
690 the TODO for cased lookups).
692 Note that to keep a plain text chunk or to just have the all of its
693 markups (chunks and tokens) be deleted just pass in an empty hash
694 reference C<{}> as the data for the chunk. It will be rendered but all
695 markups will be replaced by the empty string.
697 =head2 Token Rendering
699 The second phase is token rendering. Markups of the form [%token%] are
700 replaced by the value of the hash element with the token as the
701 key. If a token's value is not defined it is replaced by the empty
702 string. This means if a token key is missing in the hash or its value
703 is undefined or its value is the empty string, the [%token%] markup
704 will be deleted in the rendering.
706 =head1 IDIOMS and BEST PRACTICES
708 With all template systems there are better ways to do things and
709 Template::Simple is no different. This section will show some ways to
710 handle typical template needs while using only the 4 markups in this
715 This conditional idiom can be when building a fresh data tree or
716 modifying an existing one.
718 $href->{$chunk_name} = $keep_chunk ? {} : '' ;
720 If you are building a fresh data tree you can use this idiom to do a
723 $href->{$chunk_name} = {} if $keep_chunk ;
725 To handle an if/else conditional use two chunks, with the else chunk's
726 name prefixed with NOT_ (or use any name munging you want). Then you
727 set the data for either the true chunk (just the plain name) or the
728 false trunk with the NOT_ name. You can use a different name for the
729 else chunk if you want but keeping the names of the if/else chunks
730 related is a good idea. Here are two ways to set the if/else data. The
731 first one uses the same data for both the if and else chunks and the
732 second one uses different data so the it uses the full if/else code
735 $href->{ ($boolean ? '' : 'NOT_') . $chunk_name} = $data
738 $href->{ $chunk_name} = $true_data ;
740 $href->{ "NOT_$chunk_name" } = $false_data ;
743 NOTE TO ALPHA USERS: i am also thinking that a non-existing key or
744 undefined hash value should leave the chunk as is. then you would need
745 to explicitly replace a chunk with the empty string if you wanted it
746 deleted. It does affect the list of styles idiom. Any thoughts on
747 this change of behavior? Since this hasn't been released it is the
750 =head2 Chunked Includes
752 One of the benefits of using include templates is the ability to share
753 and reuse existing work. But if an included template has a top level
754 named chunk, then that name would also be the same everywhere where
755 this template is included. If a template included another template in
756 multiple places, its data tree would use the same name for each and
757 not allow unique data to be rendered for each include. A better way is
758 to have the current template wrap an include markup in a named chunk
759 markup. Then the data tree could use unique names for each included
760 template. Here is how it would look:
762 [%START foo_prime%][%INCLUDE foo%][%START foo_prime%]
764 [%START foo_second%][%INCLUDE foo%][%START foo_second%]
766 See the TODO section for some ideas on how to make this even more high level.
768 =head2 Repeated Sections
770 If you looked at the markup of Template::Simple you have noticed that
771 there is no loop or repeat construct. That is because there is no need
772 for one. Any chunk can be rendered in a loop just by having its
773 rendering data be an anonymous array. The renderer will loop over each
774 element of the array and do a fresh rendering of the chunk with this
775 data. A join (on '') of the list of renderings replaces the original
776 chunk and you have a repeated chunk.
778 =head2 A List of Mixed Styles
780 One formating style is to have a list of sections each which can have
781 its own style or content. Template::Simple can do this very easily
782 with just a 2 level nested chunk and an array of data for
783 rendering. The outer chunk includes (or contains) each of the desired
784 styles in any order. It looks like this:
786 [%START para_styles%]
788 [%INCLUDE para_style_main%]
791 [%INCLUDE para_style_sub%]
793 [%START footer_style%]
794 [%INCLUDE para_style_footer%]
798 The other part to make this work is in the data tree. The data for
799 para_styles should be a list of hashes. Each hash contains the data
800 for one pargraph style which is keyed by the style's chunk name. Since
801 the other styles's chunk names are not hash they are deleted. Only the
802 style which has its name as a key in the hash is rendered. The data
803 tree would look something like this:
807 main_style => $main_data,
810 sub_style => $sub_data,
813 sub_style => $other_sub_data,
816 footer_style => $footer_data,
822 The test scripts use a common test driver module in t/common.pl. It is
823 passed a list of hashes, each of which has the data for one test. A
824 test can create a ne Template::Simple object or use the one from the
825 previous test. The template source, the data tree and the expected
826 results are also important keys. See the test scripts for examples of
827 how to write tests using this common driver.
833 This is the name of the test and is used by Test::More
837 This is a hash ref of the options passed to the Template::Simple
838 constructor. The object is not built if the C<keep_obj> key is set.
842 If set, this will make this test keep the Template::Simple object from
843 the previous test and not build a new one.
847 This is the template to render for this test. If not set, the test
848 driver will use the template from the previous test. This is useful to
849 run a series of test variants with the same template.
853 This is the data tree for the rendering of the template.
857 This is the text that is expected after the rendering.
861 If set, this test is skipped.
867 Even though this template system is simple, that doesn't mean it can't
868 be extended in many ways. Here are some features and designs that
869 would be good extensions which add useful functionality without adding
872 =head2 Compiled Templates
874 A commonly performed optimization in template modules is to precompile
875 (really preparse) templates into a internal form that will render
876 faster. Precompiling is slower than rendering from the original
877 template which means you won't want to do it for each rendering. This
878 means it has a downside that you lose out when you want to render
879 using templates which change often. Template::Simple makes it very
880 easy to precompile as it already has the regexes to parse out the
881 markup. So instead of calling subs to do actual rendering, a
882 precompiler would call subs to generate a compiled rendering tree.
883 The rendering tree can then be run or processes with rendering data
884 passed to it. You can think of a precompiled template as having all
885 the nested chunks be replaced by nested code that does the same
886 rendering. It can still do the dynamic rendering of the data but it
887 saves the time of parsing the template souice. There are three
888 possible internal formats for the precompiled template:
894 This precompiler will generate source code that can be stored and/or
895 eval'ed. The eval'ed top level sub can then be called and passed the
898 =item Closure call tree
900 The internal format can be a nested set of closures. Each closure would contain
901 private data such as fixed text parts of the original template, lists
902 of other closures to run, etc. It is trivial to write a basic closure
903 generator which will make build this tree a simple task.
905 =item Code ref call tree
907 This format is a Perl data tree where the nodes have a code reference
908 and its args (which can be nested instances of the same
909 nodes). Instead of executing this directly, you will need a small
910 interpreter to execute all the code refs as it runs through the tree.
912 This would make for a challenging project to any intermediate Perl
913 hacker. It just involves knowing recursion, data trees and code refs.
914 Contact me if you are interested in doing this.
918 =head2 Cased Hash Lookups
920 One possible option is to allow hash renderings to always use upper or
921 lower cased keys in their lookups.
923 =head2 Render tokens before includes and chunks
925 Currently tokens are rendered after includes and chunks. If tokens
926 were rendered in a pass before the others, the include and chunk names
927 could be dynamically set. This would make it harder to precompile
928 templates as too much would be dynamic, i.e. you won't know what the
929 fixed text to parse out is since anything can be included at render
930 time. But the extra flexibility of changing the include and chunk
931 names would be interesting. It could be done easily and enabled by an
936 There are two different potential areas in Template::Simple that could
937 use plugins. The first is with the rendering of chunkas and
938 dispatching based on the data type. This dispatch table can easily be
939 replaced by loaded modules which offer a different way to
940 render. These include the precompiled renderers mentioned above. The
941 other area is with code references as the data type. By defining a
942 closure (or a closure making) API you can create different code refs
943 for the rendering data. The range of plugins is endless some of the
944 major template modules have noticed. One idea is to make a closure
945 which contains a different Template::Simple object than the current
946 one. This will allow rendering of a nested chunk with different rules
947 than the current chunk being rendered.
951 Some templaters have options to properly escape data for some types of
952 text files such as html. this can be done with some variant of the
953 _render_hash routine which also does the scalar rendering (which is
954 where data is rendered). The rendering scalars code could be factored
955 out into a set of subs one of which is used based on any escaping
958 =head2 Data Tree is an Object
960 This is a concept I don't like but it was requested so it goes into
961 the TODO file. Currently C<render> can only be passed a regular
962 (unblessed) ref (or a scalar) for its data tree. Passing in an object
963 would break encapsulation and force the object layout to be a hash
964 tree that matches the layout of the template. I doubt that most
965 objects will want to be organized to match a template. I have two
966 ideas, one is that you add a method to that object that builds up a
967 proper (unblessed) data tree to pass to C<render>. The other is by
968 subclassing C<Template::Simple> and overriding C<render> with a sub
969 that does take an object hash and it can unbless it or build a proper
970 data tree and then call C<render> in SUPER::. A quick solution is to
971 use C<reftype> (from Scalar::Utils) instead of C<ref> to allow object
972 hashes to be passed in.
974 =head2 Includes and Closure Synergy
976 By pairing up an include template along with code that can generate
977 the appropriate data tree for its rendering, you can create a higher
978 level template framework (the synergy). Additional code can be
979 associated with them that will handle input processing and
980 verification for the templates (e.g. web forms) that need it. A key to
981 this will be making all the closures for the data tree. This can be
982 greatly simplified by using a closure maker sub that can create all
983 the required closures.
985 =head2 Metafields and UI Generation
987 Taking the synergy up to a much higher level is the concept of meta
988 knowledge of fields which can generate templates, output processing
989 (data tree generation), input processing, DB backing and more. If you
990 want to discuss such grandiose wacky application schemes in a long
991 rambling mind bending conversation, please contact me.
993 =head2 More Examples and Idioms
995 As I convert several scripts over to this module (they all used the
996 hack version), I will add them to an examples section or possibly put
997 them in another (pod only) module. Similarly the Idioms section needs
998 rendering and could be also put into a pod module. One goal requested
999 by an early alpha tester is to keep the primary docs as simple as the
1000 markup itself. This means moving all the extra stuff (and plenty of
1001 that) into other pod modules. All the pod modules would be in the same
1002 cpan tarball so you get all the docs and examples when you install
1007 Uri Guttman, C<< <uri at sysarch.com> >>
1011 Please report any bugs or feature requests to
1012 C<bug-template-simple at rt.cpan.org>, or through the web interface at
1013 L<http://rt.cpan.org/NoAuth/ReportBug.html?Queue=Template-Simple>.
1014 I will be notified, and then you'll automatically be notified of progress on
1015 your bug as I make changes.
1019 You can find documentation for this module with the perldoc command.
1021 perldoc Template::Simple
1023 You can also look for information at:
1027 =item * RT: CPAN's request tracker
1029 L<http://rt.cpan.org/NoAuth/Bugs.html?Dist=Template-Simple>
1033 L<http://search.cpan.org/dist/Template-Simple>
1037 =head1 ACKNOWLEDGEMENTS
1039 I wish to thank Turbo10 for their support in developing this module.
1041 =head1 COPYRIGHT & LICENSE
1043 Copyright 2006 Uri Guttman, all rights reserved.
1045 This program is free software; you can redistribute it and/or modify it
1046 under the same terms as Perl itself.
1051 find templates and tests
1059 delete_templates test
1067 slurp dependency in makefile.pl