Help:Templates

If you have standard texts you want to include on several pages, the MediaWiki template feature comes into play.

An overview over the existing templates in this wiki can be found in the Category:Templates.

Special characters in templates

Equal sign '='

Equal signs within a template notation are used for parameter=value pairs, e.g. {{Category|description=text}}.

If an equal sign is part of the value, it has to be enclosed with <nowiki>=</nowiki>. For example:

{{Note|a^2 <nowiki>=</nowiki> b^2 + c^2}}

Creation

Templates are standard wiki pages whose content is designed to be transcluded (embedded) inside other pages. Templates follow a convention that the name is prefixed with "Template:", assigning it to that namespace. Therefore you can create them like any other wiki page.

Usage

Templates are wiki pages which can be used in other pages in three ways:

• {{Name}} 'transcludes' (i.e. includes a copy of) the content of the template (stored in the page [[Template:Name]]) whenever the page containing the template transclusion is fetched and displayed; i.e. if the template is later changed, the displayed transcluding page will automatically change too
• {{subst:Name}} replaces that string with the contents of the template, in the source of the transcluding page, when you save that page; the copy of the template contents can then be edited normally (and separately from the original in the template page). To Note: don't use this if you are looking to continually propagate changes from the source template to the page(s) that references it.
• {{msgnw:Name}} includes the template in a form that displays it as raw wiki syntax (the way <nowiki> does) when the page containing it is fetched.

In fact, an ordinary wiki page can also be used as a template, simply by specifying the namespace it resides in, so:

• {{Template:Pagename}} includes [[Template:Pagename]]
• {{Foo:Pagename}} includes [[Foo:Pagename]]
• {{:Pagename}} includes [[Pagename]]
  • {{subst::Pagename}} replaces itself with the contents of [[Pagename]]

If no such namespace exists, the full title is assumed to be a template:

• {{Foo:Bar}} includes [[Template:Foo:Bar]]

Parameters

Template with numbered parameters
'''A little thank you...'''<br /> <small>for {{{1}}}.<br /> hugs, {{{2}}}</small>
You type	You get
{{Thankyou|all your hard work|Joe}}
with named parameters
'''A little thank you...'''<br /> <small>for {{{reason}}}.<br /> hugs, {{{signature}}}</small>
You type	You get
{{Thankyou |reason=all your hard work |signature=Joe}}

You can define parameters in templates either numbered as {{{1}}} or named {{{param}}}. Please note that there are a set of three curly braces ({{{ and }}}) around each parameter. This is different than normal template name usage.

Example: You want a little thank you note you can put on the talk page of other users. It will contain a reason and your signature. You could create Template:Thankyou to enter your text, as in the example in the table.

When using the template on a page, you fill in the parameter values, separated by a pipe char (|): {{Thankyou|all your hard work|Joe}}. For named parameters use "name=value" pairs separated by a pipe char: {{Thankyou|reason=all your hard work|signature=Joe}}. The advantage of using named parameters in your template is that they are flexible in order. It also makes the template easier to understand if you have many parameters. If you want to change the order of numbered parameters, you have to mention them explicitly: {{Thankyou|2=Joe|1=all your hard work}}.

You can also provide default values for parameters, i.e. values that are going to be used if no value is provided for a parameter. For example, {{{reason|all your hard work}}} would result in "all your hard work" if no value was provided for the parameter reason.

Control template inclusion

You can control template inclusion by the use of <noinclude> and <includeonly> tags.

Anything between <noinclude> and </noinclude> will be processed and displayed only when the template's page is being viewed directly.

Possible applications are:

• Categorising templates
• Interlanguage links to similar templates in other languages
• Explanatory text about how to use the template

The converse is <includeonly>. Text between <includeonly> and </includeonly> will be processed and displayed only when the page is being included. The obvious application is to add all pages containing a given template to a category, without putting the template itself into that category.

Note: when you change the categories applied by a template, the categorization of the pages that use that template may not be updated until some time later: this is handled by the job queue.

Organizing templates

New templates have to be documented using the {{Template:Template}}. Templates also should be organized in categories, so others can find them easier.

See also

• http://en.wikipedia.org/wiki/Help:Template - detailed description of templates
• Help:Variables – fancy stuff you may find in some templates