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NAME

Parse::Template::Base -

SYNOPSIS

EXPORTS

Nothing exported by default

DEPENDENCIES

This module requires these other modules and libraries:

    Data::Hub::Courier
    Parse::Padding
    Parse::Template::Arguments
    Error::Logical
    Error::Programatic
    Perl::Module
    Data::Hub::Util
    Parse::Template::ArgumentStack
    Algorithm::KeyGen

DESCRIPTION

EXAMPLES

This example:

  # Simple replacement
  use Parse::Template::Standard;
  my $t = 'Hello [#name]';
  my $p = new Parse::Template::Standard();
  my $o = $p->compile_text(\$t, {name => 'World'});
  return $$o;

will return:

  Hello World

This example:

  # Variable expansion
  use Parse::Template::Standard;
  my $t = 'Hello [#name]';
  my $p = new Parse::Template::Standard();
  my $o = $p->compile_text(\$t, {name => '[#next]', next => 'World'});
  return $$o;

will return:

  Hello World

This example:

  # Nested elements
  use Parse::Template::Standard;
  my $t = 'Hello [#data/name]';
  my $p = new Parse::Template::Standard();
  my $o = $p->compile_text(\$t, {data => {name => 'World'}});
  return $$o;

will return:

  Hello World

This example:

  # Dynamic expansion
  use Parse::Template::Standard;
  my $t = 'Hello [#[#name]]';
  my $p = new Parse::Template::Standard();
  my $o = $p->compile_text(\$t, {name => 'next', next => 'World'});
  return $$o;

will return:

  Hello World

PUBLIC INTERFACE

new

Constructor

options:

  -begin => $begin_str          # Begins match (default '[#')
  -end => $end_str              # Ends match (default ']')
  -close => $close_str          # Closes a block (default 'end')
  -directive => $directive_str  # Identifies a directive (default ':')
  -out => \$output              # Where output is written

Default_Context

Default (initial) context

set_directives

Set the directive handlers for each given name-value pair

set_directive

Set the directive handler for a given name-value pair

get_directive

Get a directive handler

where:

  $name   directive name
  $idx    0 for begin, 1 for end

compile

Main invokation method

compile_text

Main invokation method

get_ctx

Get the current context from the context stack

use

Add a namespace on to the local stack

Calls to use must match calls to un-use within the same context

unuse

Remove the last used namespace from the local stack

Calls to use must match calls to un-use within the same context

eval

Evaluate the given element

eval_fields

Walk through fields locically returning the [uncompiled] value

This routine does the work of processing the variable spec with consideration of the `x ? y : z`, `&&` and `||` operations. For instance:

 a
 a || b
 t ? a : b
 t ? f || a : b && c
 f ? f || c : b && a

See also: `src/test/perl/t-eval-fields.pl`

get_compiled_value

Get a variable as a string and compile if necessary

get_value_str

Get a variable value as a string

See also: "get_value"

value_to_string

Get the string representation of a value

get_value

Get a variable value

$addr is passed by-reference because we will update it when applying local path information.

end_pos

Find the position of the corresponding end directive

All directives nested SHOULD be either inline (they do not slurp) or blocks (they have an end directive).

All nested directives MUST also have their own end directive. This is not currently the case, so we do our best. Take this scenario:

  [#:set foo]
    This is a block
  [#:end set]

Which is just fine. However, this is difficult:

  [#:set foo]
    [#:set bar = 'Bar']
    This is a block
  [#:end set]

Because we don't know that the nested `:set` directive is inline. So, we ask for the `$to_eof` parameter. If this is true, then we will return the normal end position, that is -1 when nested occurences are not paired up. Otherwise we will return the end position of the *last* corresponding end directive. This is the best we can do without more information, and passing or garnering that information is considered too expensive an operation at this level.

Provisions have been made only considering the `:set` and `:into` directives. -Ryan 11/2012

block_pos

Return the begin and end block positions

Similar in spirit to "substr_pos" except this routine uses regular expressions to ensure a nexted '[#abcd' does not count as a nested '[#ab' and this routine does not track all sub-indexes.

substr_pos

Return positions of begin and end markers

This routine recognizes $begin_marker and $end_marker as a balanced pair.

Example 1:

  $begin_marker = [#
  $end_marker   = ]
  a [#b [#c] [#d]] e
    ^            ^
  returns [[2, 15]]

Example 2:

  $begin_marker = [#if
  $end_marker   = [#end if]
  [#if true]do something[#end if]
  ^                     ^
  returns [[0, 22]]

This example:

  use Parse::Template::Base;
  my $p = new Parse::Template::Base;
  my $text = '<<>>';
  my @pos = $p->substr_pos(\$text, '<', '>', 0);
  join ',', map {join '-', @$_} @pos;

will return:

  0-3,1-2

PACKAGE INTERNALS

_create_context

Add a new context on to the context stack

where %args can be any combination of:

  text      => \$text,    # Template text
  path      => $path,     # Template path
  name      => $name,     # Template name
  out       => \$out,     # Where to write the result
  scope     => $scope,    # Stack index limit (invokation is being deferred)
  regions   => \@regions, # Known regions (\$text is being re-used)
  esc       => $chars     # Escape chars in resolved values

_find_regions

Glean the begin and end indexes into template text

returns:

  [\@match1, \@match2, ...]
where each C<\@match> is:

  [
    $beg,       # Begin index
    $end,       # End index
    $nested,    # Has nested regions (1|undef)
  ]

_remove_context

Remove the current context from the context stack

_invoke

Implementation method

See _create_context for %args

_slurp

Slurp the contents of for block-type directive

If $to_eof is a true value and an end directive is not found, _slurp will read to the end of the template text.

If $to_eol is not defined, it is true, which means the newlines after the closing tag will be consumed.

_padding

Get number of preceeding and trailing whitespace characters

Returns an array of widths: ($w1, $w2)

  $w1 = Number of preceeding whitespace characters
  $w2 = Number of trailing whitespace characters

Returns an (0, 0) if non-whitespace characters are immediately found in the preceeding or trailing regions.

We will look up to 80 characters in front of the current position.

AUTHORS

    Ryan Gies <ryangies@cpan.org>

COPYRIGHT

    Copyright (C) 2014-2016 by Ryan Gies. All rights reserved.
    Copyright (C) 2006-2013 by Livesite Networks, LLC. All rights reserved.
    Copyright (C) 2000-2005 by Ryan Gies. All rights reserved.
    Redistribution and use in source and binary forms, with or without 
    modification, are permitted provided that the following conditions are met:
    * Redistributions of source code must retain the above copyright notice, 
    this list of conditions and the following disclaimer.
    * The origin of this software must not be misrepresented; you must not 
    claim that you wrote the original software. If you use this software in a 
    product, an acknowledgment in the product documentation would be 
    appreciated but is not required.
    * Altered source versions must be plainly marked as such, and must not be 
    misrepresented as being the original software.
    * The name of the author may not be used to endorse or promote products 
    derived from this software without specific prior written permission.

    THIS SOFTWARE IS PROVIDED BY THE AUTHOR "AS IS" AND ANY EXPRESS OR IMPLIED 
    WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
    MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 
    EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, 
    EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
    OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
    INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 
    CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
    IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY 
    OF SUCH DAMAGE.
    To the best of our knowledge, no patented algorithms have been used. However, we
    do not have the resources to carry out a patent search, and therefore cannot 
    give any guarantee of the above statement.