{#example_1}
{!--
  -- Chunk's conditional expressions are useful but somewhat
  -- limited.  The lightweight parser can only handle these
  -- simple string value tests listed below.
  --
  -- Sorry, {.if} conditions may not include greater-than
  -- or less-than tests (eg > < <= gt lt etc). Also, Chunk's
  -- conditional expressions do not support the && and ||
  -- (and/or) operators. However, the inclusion of regular
  -- expression pattern matching should cover most of your
  -- exotic comparison needs. Anything more involved is best
  -- handled in your business logic anyway, and not in your
  -- presentation layer.
  --
  -- The following tests will function as expected:
  --}

<ol>

{!-- existence --}
 <li>{.if ($flag) }Flag is defined{/if}</li>
 <li>{.if (!$flag) }Flag is not defined{/if}</li>

{!-- equality / inequality --}
 <li>{.if ($tag == apples) }Tag was apples{/if}</li>
 <li>{.if ($tag != apples) }Tag was not apples{/if}</li>
 <li>{.if ($tag == "apples") }Tag was "apples"{/if}</li>
 <li>{.if ($tag != "apples") }Tag was not "apples"{/if}</li>
 <li>{.if ($tag_a == $tag_b) }Tag A equals Tag B{/if}</li>
 <li>{.if ($tag_a != $tag_b) }Tag A does not equal Tag B{/if}</li>

{!-- pattern matching --}
 <li>{.if ($tag =~ /apples|oranges/) }Tag is apples or oranges{/if}</li>
 <li>{.if ($tag !~ /apples|oranges/) }Tag is neither apples nor oranges{/if}</li>

</ol>

{#}

Theme theme = new Theme("examples");

// Fetch template from this file: themes/examples/ifelse.chtml
// Inside that file there is a template "snippet" named #example_1
Chunk html = theme.makeChunk("ifelse#example_1");

html.set("flag", "TRUE");
html.set("tag","apples");

html.set("tag_a","apples");
html.set("tag_b","oranges");

buffer.append( "FIRST RUN:\n" );
buffer.append( html.toString() );

// The same Chunk can be re-used with different tag values
html.resetTags();

// note: not setting a value for "flag" this time
html.set("tag","bananas");

html.set("tag_a","kumquat");
html.set("tag_b","kumquat");

buffer.append( "SECOND RUN:\n" );
buffer.append( html.toString() );

{#example_2}

<p>{$state} is a

{.if ($color == red) }
  Conservative
{.elseIf ($color == blue) }
  Liberal
{.else}
  Centrist
{/if}

state.</p>

{#}

Theme theme = new Theme("examples");

// Fetch template from this file: themes/examples/ifelse.chtml
// Inside that file there is a template "snippet" named #example_2
Chunk html = theme.makeChunk("ifelse#example_2");

html.set("state", "Texas");
html.set("color", "red");

html.render( out );

{#example_3}
{!-- Nest your conditionals, no problem. --}

<p>{$state} is a

{.if ($color == red) }
  {.if ($radical) }
    Tea Party
  {.else}
    Conservative
  {/if}
{.elseIf ($color == blue) }
  {.if ($radical) }
    Green
  {.else}
    Liberal
  {/if}
{.else}
  Centrist
{/if}

state.</p>

{#}

Theme theme = new Theme("examples");

// Fetch template from this file: themes/examples/ifelse.chtml
// Inside that file there is a template "snippet" named #example_3
Chunk html = theme.makeChunk("ifelse#example_3");

html.set("state", "Vermont");
html.set("color", "blue");
html.set("radical", "TRUE");

html.render( out );