View source for Help:Templates

{{Nutshell|A wiki page in which contents can be displayed in other locations around the wiki. This allow an editor to make a change once and have the changes appear numerous places throughout the wiki.}}{{Banner|See the [[Help:Template directory|list of templates on USApedia]] or [[mediawikiwiki:Help:Templates|Help:Templates on MediaWiki]] for full documentation on templates.}}
{{#ev:YouTube|https://www.youtube.com/watch?v=IJ4BM5MFXmc|400|right|Introduction to templates}}
{{#ev:YouTube|https://www.youtube.com/watch?v=SsLahlGX0Ls|400|right|Basic formatting of templates}}
{{#ev:YouTube|https://www.youtube.com/watch?v=X0QD5HT2qgc|400|right|Introduction to template variables}}{{Help Box}}
A '''template''' is a USApedia page created to be included in other pages. Templates usually contain repetitive material that might need to show up on any number of articles or pages. They are commonly used for Boilerplate messages, standard warnings or notices, [[Template:Infobox|infoboxes]], [[Template:Navbox|navigational boxes]] and similar purposes.

The most common method of inclusion is called [[Wikipedia:Transclusion|transclusion]], where the wikitext of the target page contains a reference to the template, using the <code><nowiki>{{Template name}}</nowiki></code> syntax.  

When [[Help:TemplateData|template data]] is added, templates can be editing using forms.  

See {{W|article=Help:Template}} and {{Mw|article=Help:Template}} for additional details.  

== Find a template ==
The [[Help:Template directory|Template directory]] is a good place to start as well as:
* [[Favorite templates]]
* [[Help:Media templates|Media templates]]
* [[Help:Templates/Banner templates]]
* [[Help:Templates/Media]]

== Adding a template ==
There are different ways of adding a template, based on the [[Editors|Editor]] you are using.

=== VisualEditor ===
* Using [[VisualEditor]] makes it easier to [[Help:Visual editor#Templates|add templates]] using the template search and [[Help:TemplateData|template data]].

=== Enhanced editor ===
To add a template using [[enhanced editor]]:
* Add <code><nowiki>{{</nowiki></code>
* Type or paste the name of the template
* Add any parameters
* Close with <code><nowiki>}}</nowiki></code>

==Infoboxes==
* See [[Template:Infobox]] for background and use cases.  These templates are used on the upper right-hand side of a page to provide a basic summary of information about a topic.  
* See [[:Category:Infobox templates]] for a list of infobox templates currently available.

==Navboxes==
* See [[Template:Navbox]] for background and use cases.  These templates are used at the bottom of a page to connected related articles together.
** See [[:Category:Navigation_Templates]] for a list of templates using Navbox

== Gardening ==
See [[USApedia:Maintenance]] for a list of gardening templates.

==Template Sandbox==
The [[:Template:Test|Test Template]] was specifically created for [[USApedians]] to to test out ideas and functionality.

==Noinclude, includeonly, and onlyinclude==
By default, when a template is transcluded (or substituted), the entire wikitext (code) of the template page gets included in that of the target page. However it is possible to modify that behaviour, using tags that specify which parts of the template code are to be included. This makes it possible to avoid transcluding information intended for display only on the template page itself, such as the template's documentation, [[categories]] and [[interwiki links]]. It is also possible to have parts of the code be transcluded, but ''not'' be processed on the template page itself (e.g. categories to be applied to the target pages which do not apply to the template). The tags are as follows
* {{tag|noinclude}} — the text between the {{tag|noinclude|open}} tags will not be included when the template is transcluded (substituted)
* {{tag|includeonly}} — the text between the {{tag|includeonly|open}} tags will be transcluded (substituted), but will not be processed on the template's own page
* {{tag|onlyinclude}} (not often used) — specifies that nothing on the page ''except'' what appears between the {{tag|onlyinclude|open}} tags will be transcluded (substituted)

Perhaps the most common issue with the use of these blocks is unwanted spaces or lines. It is important to remember that the effect of these tags ends immediately after the last angle bracket, not on the next line or with the next visible character.

These tags can be nested inside each other, though (for a given page) this really only applies to the {{tag|onlyinclude|open}} tag; nesting {{tag|includeonly|open}} and {{tag|noinclude|open}} tags is fairly pointless. Be careful not to split the tags, however. Constructions like this {{code|<nowiki><onlyinclude> abc <includeonly> def </onlyinclude> ghi </includeonly></nowiki>}} will not work as expected. Use the "first opened, last closed" rule that is standard for XML.

== Standards templates to be used on template pages ==
* {{tlx|documentation}} - add documentation on purpose of template and how to use it; must create a "/doc" [[subpage]]
* {{tlx|documentation subpage}} - explains that it is a "/doc" [[subpage]]
==Usage syntax==

===Parameters===
{{shortcut|H:PARAMETER|WP:PARAMETER}}
The basic transclusion syntax given above can be extended by the addition of [[parameter]]s, which are used to control the template's output. The syntax for this is
{{tnull|{{var|Template name}}|{{var|parameter}}|{{var|parameter}}|{{var|...}}}}
where <code>{{var|Template name}}</code> is the name of the template, and each <code>{{var|parameter}}</code> may either contain just a value (these are called ''{{dfn|unnamed parameters}}'') or be of the form <code>{{var|name}}={{var|value}}</code> (''{{dfn|named parameters}}''). The first, second, third, etc. unnamed parameters will be given the names <code>1</code>, <code>2</code>, <code>3</code>, etc.

Whitespace characters (spaces, tabs, returns) are stripped from the beginnings and ends of {{em|named}} parameter names and values, but not from the middle: thus <code><nowiki>{{ ... | myparam = this is a test }}</nowiki></code> has the same effect as <code><nowiki>{{ ... |myparam=this is a test}}</nowiki></code>. This does not apply to {{em|unnamed}} parameters, where all whitespace characters are preserved.

Which parameters (if any) can or should be passed to a template and how they are to be named depends on the coding of that template. Named parameters can be defined in any order. Superfluous or misnamed parameters will be ignored; undefined parameters will be assigned default values. If a parameter is defined more than once, the last value takes effect.

The value of a parameter can be the empty string, such as when the pipe or equals sign is followed immediately by the next pipe or the closing braces. This is different from omitting the parameter altogether, which leaves it undefined, although templates are often coded so as to behave the same in both cases.

Parameters can be specified (and will do nothing) even if not represented in the template's code. For example, {{para|reason}} is frequently used as a pseudo-parameter to explain briefly in the wikisource why the template was placed.{{efn|Some templates, such as {{tlx|Requested move}}, have code to display {{para|reason}} as visible output; whether to do so is determined on a template-by-template basis.}} Some templates call [[Module:Check for unknown parameters]] to warn the editor if a parameter is being used that is not accounted for in the template's code; this is mostly used for [[Help:Infobox|infoboxes]] and other templates with a large number of complicated parameters, where the presence of an unknown one is usually an unintentional error. If you update such a template to include a new parameter, its call to the module must also be updated to include the new parameter.

===Calling===
{{Further|mw:Help:Magic words}}

Using a template is much like calling a [[Subroutine|function]] in a programming language – call it, and it returns a value (the [[Input/output|output]]). Like functions, some templates accept parameters that change the output.

In [[MediaWiki]], the [[wiki software]] that Wikipedia uses, [[Help:Magic words#Variables|variables]] have a more specific meaning that distinguishes them from templates, but they are both identified by double [[Curly brackets|braces]] <code><nowiki>{{ }}</nowiki></code> and they both return a value.

Whereas MediaWiki variable names are all uppercase, template names have the same basic features and [[WP:NCHASHTAG|limitations]] as all [[Help:Page name|page names]]: they are case-sensitive (except for the first character); [[underscore]]s are parsed as spaces; and they cannot contain any of these characters: <code><nowiki># < > [ ] | { }</nowiki></code>. This is because those are reserved for [[wiki markup]] and [[HTML]].

The [[number sign]] <code>#</code> is called a [[URI fragment|fragment identifier]] because it denotes a {{em|fragment}} or section of a document (such as a [[Help:Section|section]] in a Wikipedia article). Although it [[WP:ANCHOR|can be used]] to link to a section of a template page (like [[Template:Portal#Example]]), there is no reason to put a fragment identifier or fragment name in a template reference. In {{tnull|Portal{{var|#Location}}|Books}}, for example, the string <code>{{var|#Location}}</code> has no purpose and is thus ignored.

===Substitution===
{{Further|Help:Substitution}}
When a template is substituted, its content is [[hard-coded]] in the page rather than [[Help:Transclusion|transcluded]]. To learn how and when to substitute a template, see {{section link|Help:Substitution|When to use substitution}}.

==Icons that are good for templates==
These icons either are or can be useful to spruce up templates.  
<gallery showfilename="yes" mode="nolines" heights="40">
File:Magnifying glass.png
File:Broom icon.png
File:LecternCourt.jpg
File:Checker-16x16.png
File:Icons-mini-file acrobat.png 
File:Pdf.gif 
File:Gnome speakernotes 30px.png
File:Disambig gray.svg
File:Blue check.png 
File:CourtGavelsmall.JPG 
File:Template-info.svg
File:Edit-copy_green.svg
File:Crystal_Clear_action_exit.svg
</gallery>
Other icons can be found in the [[:category:icons | icons]] category.

{{USApedia}}

== References ==
[[Category:Help]]
[[Category:Pages with YouTube videos]]
<references group="lower-alpha" />{{Purge box}}