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		<title>Rboatright: 1 revision(s)</title>
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		<updated>2009-07-23T01:38:53Z</updated>

		<summary type="html">&lt;p&gt;1 revision(s)&lt;/p&gt;
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				&lt;td colspan=&quot;1&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 01:38, 23 July 2009&lt;/td&gt;
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		<author><name>Rboatright</name></author>
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		<title>67.177.186.240 at 14:27, 12 July 2009</title>
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		<updated>2009-07-12T14:27:37Z</updated>

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&lt;p&gt;&lt;b&gt;New page&lt;/b&gt;&lt;/p&gt;&lt;div&gt;When applying [[Help:Extension:ParserFunctions|ParserFunctions]] to [[Help:Template|template]] parameters, a pipe symbol (&amp;quot;|&amp;quot;) may be used to provide the empty string as default value, in order to indicate how to handle things if a parameter is or is not passed in.&lt;br /&gt;
&lt;br /&gt;
*&amp;lt;tt&amp;gt;&amp;lt;nowiki&amp;gt;{{{1}}}&amp;lt;/nowiki&amp;gt;&amp;lt;/tt&amp;gt;&lt;br /&gt;
&lt;br /&gt;
:;Sample A: &amp;lt;tt&amp;gt;&amp;lt;nowiki&amp;gt;{{#if: {{{1}}} | Parameter 1 is not defined, or is defined and non-null/non-empty. | Parameter 1 is null. It contains only empty string(s) or breaking space(s) etc.}}&amp;lt;/nowiki&amp;gt;&amp;lt;/tt&amp;gt;&lt;br /&gt;
&lt;br /&gt;
:;Result: &amp;lt;tt&amp;gt;{{#if: {{{1}}} | Parameter 1 is not defined, or is defined and non-null/non-empty. | Parameter 1 is null. It contains only empty string(s) or breaking space(s) etc.}}&amp;lt;/tt&amp;gt;&lt;br /&gt;
&lt;br /&gt;
*&amp;lt;tt&amp;gt;&amp;lt;nowiki&amp;gt;{{{1|}}}&amp;lt;/nowiki&amp;gt;&amp;lt;/tt&amp;gt;&lt;br /&gt;
&lt;br /&gt;
:;Sample B: &amp;lt;tt&amp;gt;&amp;lt;nowiki&amp;gt;{{#if: {{{1|}}} | Parameter 1 is defined and non-null/non-empty. | Parameter 1 is not defined, or is defined but null. It contains only empty string(s) or breaking space(s) etc.}}&amp;lt;/nowiki&amp;gt;&amp;lt;/tt&amp;gt;&lt;br /&gt;
&lt;br /&gt;
:;Result: &amp;lt;tt&amp;gt;{{#if: {{{1|}}} | Parameter 1 is defined and non-null/non-empty. | Parameter 1 is not defined, or is defined but null. It contains only empty string(s) or breaking space(s) etc.}}&amp;lt;/tt&amp;gt;&lt;br /&gt;
&lt;br /&gt;
;Comparison&lt;br /&gt;
{| class=&amp;quot;wikitable&amp;quot;&lt;br /&gt;
! Condition of parameter 1&lt;br /&gt;
! Sample A: &amp;lt;nowiki&amp;gt;{{{1}}}&amp;lt;/nowiki&amp;gt;&lt;br /&gt;
! Sample B: &amp;lt;nowiki&amp;gt;{{{1|}}}&amp;lt;/nowiki&amp;gt;&lt;br /&gt;
|-&lt;br /&gt;
|not defined||'''TRUE'''||''FALSE''&lt;br /&gt;
|-&lt;br /&gt;
|defined but null/empty||''FALSE''||''FALSE''&lt;br /&gt;
|-&lt;br /&gt;
|defined and NOT null/empty||'''TRUE'''||'''TRUE'''&lt;br /&gt;
|-&lt;br /&gt;
|}&lt;br /&gt;
&lt;br /&gt;
The second usage (&amp;lt;nowiki&amp;gt;{{{1|}}}&amp;lt;/nowiki&amp;gt;) is often the desired way to handle situations where a parameter exists, but is comprised only of empty space.&lt;br /&gt;
&lt;br /&gt;
==See also==&lt;br /&gt;
*[[Help:Extension:ParserFunctions]]&lt;br /&gt;
*[[Help:Template]]&lt;br /&gt;
&lt;br /&gt;
[[Category:Help|Parser functions in templates]]&lt;/div&gt;</summary>
		<author><name>67.177.186.240</name></author>
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