there will continue to be code sharing between the two projects. (Acutally
I will try and keep applicable fixes in sync with TT).
+CGI::Ex::Template uses a recursive regex based grammar (early versions
+before the 2.10 release did not). This allows for the embedding of opening
+and closing tags inside other tags (as in [% a = "[% 1 + 2 %]" ; a|eval %]).
+The individual methods such as parse_expr and play_expr may be used by external
+applications to add TT style variable parsing to other applications.
+
Most of the standard Template::Toolkit documentation covering directives,
variables, configuration, plugins, filters, syntax, and vmethods should
apply to CET just fine (This pod tries to explain everything - but there is
In general the following statements are true:
If you load a new Template object each time and pass a filename, CET
- is around 4 times faster.
+ is around 3.5 times faster.
If you load a new Template object and pass a string ref, CET
- is around 3.5 times faster.
+ is around 3 times faster.
If you load a new Template object and use CACHE_EXT, CET
is around 1.5 times faster.
then CET is 50% faster.
If you use Template::Stash::XS with a cached in memory template,
- then CET is about as fast.
-
- Using TT with a compiled-in-memory template is only 33%
- faster than CET with a new object compiling each time.
+ then CET is about as fast. But if you use CGI::Ex::Template::XS,
+ the CETX is faster still (about twice as fast as CET).
It is pretty hard to beat the speed of XS stash with compiled in
memory templates. Many systems don't have access to those so
CET may make more sense. Hopefully as TT is revised, many of the CET
speed advantages can be incorporated so that the core TT is just as
-fast or faster.
+fast or faster. This was last updated at version 2.10 of CET and
+2.18 of TT.
So should you use CGI::Ex::Template ? Well, try it out. It may
give you no visible improvement. Or it could.
[% (a ~ b).length %]
- [% "hi".repeat(3) %]
+ [% "hi".repeat(3) %] # = hihihi
- [% {a => b}.size %]
+ [% {a => b}.size %] # = 1
=item The "${" and "}" variable interpolators can contain expressions,
not just variables.
[% color = qw/Red Blue/; FOR [1..4] ; color.${ loop.index % color.size } ; END %]
# = RedBlueRedBlue
+=item Tags can be nested.
+
+ [% f = "[% (1 + 2) %]" %][% f|eval %] # = 3
+
=item Arrays can be accessed with non-integer numbers.
[% [0..10].${ 2.3 } %] # = 3
=item CET does not generate Perl code.
-It generates an "opcode" tree.
+It generates an "opcode" tree. The opcode tree is an arrayref
+of scalars and array refs nested as deeply as possible. This "simple"
+structure could be shared TT implementations in other languages
+via JSON or YAML.
=item CET uses storable for its compiled templates.
If EVAL_PERL is off, CET will not eval_string on ANY piece of information.
+=item There is eval_filter and MACRO recursion protection
+
+You can control the nested nature of eval_filter and MACRO
+recursion using the MAX_EVAL_RECURSE and MAX_MACRO_RECURSE
+configuration items.
+
=item There is no context.
CET provides a context object that mimics the Template::Context
=item There is no grammar.
-CET has its own built in recursive grammar system.
+CET has its own built-in recursive regex based grammar system.
=item There is no VIEW directive.
-
-=item There are no references.
-
-There were in initial beta tests, but it was decided to remove the little used feature which
-took a length of code to implement.
-
=item The DEBUG directive is more limited.
It only understands DEBUG_DIRS (8) and DEBUG_UNDEF (2).
=item When debug dirs is on, directives on different lines separated by colons show the line they
are on rather than a general line range.
-=item There is no ANYCASE configuration item.
-
-There was in initial beta tests, but it was dropped in favor of consistent parsing syntax (and
-a minimal amount of speedup).
-
-=item There is no V1DOLLAR configuration item.
-
-This is a TT version 1 compatibility item and is not available in CET.
-
=back
=head1 VARIABLES
CGI::Ex::Template=HASH(0x814dc28)
- $VAR1 = [ \[ '+', '1', '2' ], 0 ];
+ $VAR1 = [ [ undef, '+', '1', '2' ], 0 ];
Each type of data (string, array and hash) have virtual methods
associated with them. Virtual methods allow for access to functions
Note: virtual methods can only be used on literal strings in CET, not in TT.
+You may also embed the current tags in strings (CET only).
+
+ [% '[% 1 + 2 %]' | eval %] Prints "3"
+
=item Double quoted strings.
Returns the string. Variable interpolation happens.
Note: virtual methods can only be used on literal strings in CET, not in TT.
+You may also embed the current tags in strings (CET only).
+
+ [% "[% 1 + 2 %]" | eval %] Prints "3"
+
=item Array Constructs.
[% [1, 2, 3] %] Prints something like ARRAY(0x8309e90).
The named tags are (duplicated from TT):
- template => ['[%', '%]'], # default
- metatext => ['%%', '%%'], # Text::MetaText
- star => ['[*', '*]'], # TT alternate
- php => ['<?', '?>'], # PHP
- asp => ['<%', '%>'], # ASP
- mason => ['<%', '>' ], # HTML::Mason
- html => ['<!--', '-->'], # HTML comments
+ asp => ['<%', '%>' ], # ASP
+ default => ['\[%', '%\]' ], # default
+ html => ['<!--', '-->' ], # HTML comments
+ mason => ['<%', '>' ], # HTML::Mason
+ metatext => ['%%', '%%' ], # Text::MetaText
+ php => ['<\?', '\?>' ], # PHP
+ star => ['\[\*', '\*\]' ], # TT alternate
+ template1 => ['[\[%]%', '%[%\]]'], # allow TT1 style
+
+If custom tags are supplied, by default they are escaped using
+quotemeta. If a third argument is given and is equal to "unquoted",
+then no quoting takes place on the new tags.
+
+ [% TAGS [<] [>] %] matches "[<] tag [>]"
+
+ [% TAGS [<] [>] unquoted %] matches "< tag >"
+
+ [% TAGS ** ** %] matches "** tag **"
+
+ [% TAGS ** ** unquoted %] Throws an exception.
=item C<THROW>
Would print:
- $VAR1 = [ \[ '*', '2', '3' ], 0 ];
+ $VAR1 = [ [ undef, '*', '2', '3' ], 0 ];
See the PLUGIN_BASE, and PLUGINS configuration items.
This shouldn't be too much hardship and offers the great return of disambiguating
virtual method access.
+=item C<\>
+
+Unary. The reference operator. Not well publicized in TT. Stores a reference
+to a variable for use later. Can also be used to "alias" long names.
+
+ [% f = 7 ; foo = \f ; f = 8 ; foo %] => 8
+
+ [% foo = \f.g.h.i.j.k; f.g.h.i.j.k = 7; foo %] => 7
+
+ [% f = "abcd"; foo = \f.replace("ab", "-AB-") ; foo %] => -AB-cd
+
+ [% f = "abcd"; foo = \f.replace("bc") ; foo("-BC-") %] => a-BC-d
+
+ [% f = "abcd"; foo = \f.replace ; foo("cd", "-CD-") %] => ab-CD-
+
=item C<++ -->
Pre and post increment and decrement. My be used as either a prefix
Right associative. Lower precedence version of the '||' operator.
-=item C<hash>
+=item C<{}>
This operator is not used in TT. It is used internally
by CGI::Ex::Template to delay the creation of a hash until the
execution of the compiled template.
-=item C<array>
+=item C<[]>
This operator is not used in TT. It is used internally
by CGI::Ex::Template to delay the creation of an array until the
These variables should be passed to the "new" constructor.
- my $obj = CGI::Ex::Template->new(
- VARIABLES => \%hash_of_variables,
- AUTO_RESET => 0,
- TRIM => 1,
- POST_CHOMP => "=",
- PRE_CHOMP => "-",
- );
+ my $obj = CGI::Ex::Template->new(
+ VARIABLES => \%hash_of_variables,
+ AUTO_RESET => 0,
+ TRIM => 1,
+ POST_CHOMP => "=",
+ PRE_CHOMP => "-",
+ );
=over 4
Boolean. Default false. Are absolute paths allowed for included files.
+=item ANYCASE
+
+Allow directive matching to be case insensitive.
+
+ [% get 23 %] prints 23 with ANYCASE => 1
+
=item AUTO_RESET
Boolean. Default 1. Clear blocks that were set during the process method.
A hashref of blocks that can be used by the process method.
- BLOCKS => {
- block_1 => sub { ... }, # coderef that returns a block
- block_2 => 'A String', # simple string
- },
+ BLOCKS => {
+ block_1 => sub { ... }, # coderef that returns a block
+ block_2 => 'A String', # simple string
+ },
Note that a Template::Document cannot be supplied as a value (TT
supports this). However, it is possible to supply a value that is
[% IF 1 %]The variable $variable had a value ${var.value}[% END %]
-
=item LOAD_PERL
Indicates if the USE directive can fall back and try and load a perl module
if the indicated module was not found in the PLUGIN_BASE path. See the
USE directive.
+=item MAX_EVAL_RECURSE (CET only)
+
+Will use $CGI::Ex::Template::MAX_EVAL_RECURSE if not present. Default is 50.
+Prevents runaway on the following:
+
+ [% f = "[% f|eval %]" %][% f|eval %]
+
+=item MAX_MACRO_RECURSE (CET only)
+
+Will use $CGI::Ex::Template::MAX_MACRO_RECURSE if not present. Default is 50.
+Prevents runaway on the following:
+
+ [% MACRO f BLOCK %][% f %][% END %][% f %]
+
=item NAMESPACE
No Template::Namespace::Constants support. Hashref of hashrefs representing
You can also sub class the module and override the undefined_get method.
+=item V1DOLLAR
+
+This allows for some compatibility with TT1 templates. The only real
+behavior change is that [% $foo %] becomes the same as [% foo %]. The
+following is a basic table of changes invoked by using V1DOLLAR.
+
+ With V1DOLLAR Equivalent Without V1DOLLAR (Normal default)
+ "[% foo %]" "[% foo %]"
+ "[% $foo %]" "[% foo %]"
+ "[% ${foo} %]" "[% ${foo} %]"
+ "[% foo.$bar %]" "[% foo.bar %]"
+ "[% ${foo.bar} %]" "[% ${foo.bar} %]"
+ "[% ${foo.$bar} %]" "[% ${foo.bar} %]"
+ "Text: $foo" "Text: $foo"
+ "Text: ${foo}" "Text: ${foo}"
+ "Text: ${$foo}" "Text: ${foo}"
+
=item VARIABLES
A hashref of variables to initialize the template stash with. These
=over 4
-=item ANYCASE
-
-This will not be supported. You will have to use the full case directive names.
-(It was in the beta code but was removed prior to release).
-
=item WRAPPER
This will be supported - just not done yet.
This will be supported - just not done yet.
-=item V1DOLLAR
-
-This will not be supported.
-
=item LOAD_TEMPLATES
CGI::Ex::Template has its own mechanism for loading and storing
one.${two().three} [ 'one', 0, '.', ['two', [], '.', 'three', 0], 0]
2.34 2.34
"one" "one"
- "one"|length [ \"one", 0, '|', 'length', 0 ]
- "one $a two" [ \ [ '~', 'one ', ['a', 0], ' two' ], 0 ]
- [0, 1, 2] [ \ [ 'array', 0, 1, 2 ], 0 ]
- [0, 1, 2].size [ \ [ 'array', 0, 1, 2 ], 0, '.', 'size', 0 ]
- ['a', a, $a ] [ \ [ 'array', 'a', ['a', 0], [['a', 0], 0] ], 0]
- {a => 'b'} [ \ [ 'hash', 'a', 'b' ], 0 ]
- {a => 'b'}.size [ \ [ 'hash', 'a', 'b' ], 0, '.', 'size', 0 ]
- {$a => b} [ \ [ 'hash', ['a', 0], ['b', 0] ], 0 ]
- 1 + 2 [ \ [ '+', 1, 2 ], 0]
- a + b [ \ [ '+', ['a', 0], ['b', 0] ], 0 ]
- a * (b + c) [ \ [ '*', ['a', 0], [ \ ['+', ['b', 0], ['c', 0]], 0 ]], 0 ]
- (a + b) [ \ [ '+', ['a', 0], ['b', 0] ]], 0 ]
- (a + b) * c [ \ [ '*', [ \ [ '+', ['a', 0], ['b', 0] ], 0 ], ['c', 0] ], 0 ]
- a ? b : c [ \ [ '?', ['a', 0], ['b', 0], ['c', 0] ], 0 ]
- a || b || c [ \ [ '||', ['a', 0], [ \ [ '||', ['b', 0], ['c', 0] ], 0 ] ], 0 ]
- ! a [ \ [ '!', ['a', 0] ], 0 ]
+ "one"|length [ [ undef, '~', "one" ], 0, '|', 'length', 0 ]
+ "one $a two" [ [ undef, '~', 'one ', ['a', 0], ' two' ], 0 ]
+ [0, 1, 2] [ [ undef, '[]', 0, 1, 2 ], 0 ]
+ [0, 1, 2].size [ [ undef, '[]', 0, 1, 2 ], 0, '.', 'size', 0 ]
+ ['a', a, $a ] [ [ undef, '[]', 'a', ['a', 0], [['a', 0], 0] ], 0]
+ {a => 'b'} [ [ undef, '{}', 'a', 'b' ], 0 ]
+ {a => 'b'}.size [ [ undef, '{}', 'a', 'b' ], 0, '.', 'size', 0 ]
+ {$a => b} [ [ undef, '{}', ['a', 0], ['b', 0] ], 0 ]
+ 1 + 2 [ [ undef, '+', 1, 2 ], 0]
+ a + b [ [ undef, '+', ['a', 0], ['b', 0] ], 0 ]
+ a * (b + c) [ [ undef, '*', ['a', 0], [ [undef, '+', ['b', 0], ['c', 0]], 0 ]], 0 ]
+ (a + b) [ [ undef, '+', ['a', 0], ['b', 0] ]], 0 ]
+ (a + b) * c [ [ undef, '*', [ [undef, '+', ['a', 0], ['b', 0] ], 0 ], ['c', 0] ], 0 ]
+ a ? b : c [ [ undef, '?', ['a', 0], ['b', 0], ['c', 0] ], 0 ]
+ a || b || c [ [ undef, '||', ['a', 0], [ [undef, '||', ['b', 0], ['c', 0] ], 0 ] ], 0 ]
+ ! a [ [ undef, '!', ['a', 0] ], 0 ]
Some notes on the parsing.
Operators are parsed as part of the variable and become part of the variable tree.
- Operators are stored in the variable tree using a reference to the arrayref - which
+ Operators are stored in the variable tree using an operator identity array which
+ contains undef as the first value, the operator, and the operator arguments. This
allows for quickly descending the parsed variable tree and determining that the next
node is an operator.
=item C<dump_parse>
-This method allows for returning a Data::Dumper dump of a parsed template. It is mainly used for testing.
+This method allows for returning a Data::Dumper dump of a parsed
+template. It is mainly used for testing.
=item C<dump_parse_expr>
-This method allows for returning a Data::Dumper dump of a parsed variable. It is mainly used for testing.
+This method allows for returning a Data::Dumper dump of a parsed
+variable. It is mainly used for testing.
=item C<exception>
=item C<play_expr>
-Turns a variable identity array into the parsed variable. This
-method is also responsible for playing operators and running virtual methods
-and filters. The method could more accurately be called play_expression.
+Play the parsed expression. Turns a variable identity array into the
+parsed variable. This method is also responsible for playing
+operators and running virtual methods and filters. The variable
+identity array may also contain literal values, or operator identity
+arrays.
=item C<include_filename>
=item C<play_operator>
-Used to execute any found operators
+Used to execute any found operators. The single argument is
+an operator identy returned by the parse_expr method (if the expression
+contained an operator). Normally you would just call play_expr
+instead and it will call play_operator if the structure
+contains an operator.
=item C<_process>
projects / chaz / p5-CGI-Ex / blobdiff