সহায়:সাঁচ: বিভিন্ন সংশোধনসমূহৰ মাজৰ পাৰ্থক্য

{{Wiki markup}}

{{shortcut|HELP:T|Wikipedia:TEMPLATE}}

 

 

 

 

 

 

'''How to do it:''' To transclude a template to an article or page, type <code><nowiki>{{template name}}</nowiki></code> in the wikitext at the place where the template is to appear. The prefix "Template:" need not be included, and an initial capital is not necessary.

 

 

'''Note:''' Attempting to transclude a template that does not exist produces a [[wp:redlink|red link]], just like linking to any other nonexistent page. Following the link allows one to create that particular template. It is not possible to transclude pages between projects (such as different language Wikipedias)&nbsp;— to use a template on another language project, a copy of the template must be created in that project.

 

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

* <code><nowiki>{{template name|parameter|parameter|...}}</nowiki></code>

The value of a parameter can be the empty string (pipe or equals sign followed immediately by the next pipe or the closing braces). This is different from leaving the parameter undefined (although templates are often coded so as to behave the same in both cases).

 

 

 

 

 

 

 

For example, type "<code>The 11th letter of the Greek alphabet is the lambda (<nowiki>{{lambda}}</nowiki>)</code>" and you will see "The 11th letter of the Greek alphabet is the lambda ({{lambda}})". You can use templates without knowing the details of their code&nbsp;— you only need to remember what result they produce (this is usually described on the template page).

 

 

{{anchor|Parameters}}

{{for|the card game|Contract bridge}}

This usage takes two unnamed parameters, but the same template can also be used with different numbers of parameters to give slightly different results, as explained in the documentation on the template page. For example, <code><nowiki>{{For||Latins|Latin (disambiguation)}}</nowiki></code> produces

Note in particular the usage with an empty parameter&nbsp;— here the consecutive pipes mean that the first parameter passed to the template is the empty string.

 

:<code><nowiki>{{payoff matrix | UL = 5 | UR = 7 | DL = 2 | DR = 9 | Name = Example usage }}</nowiki></code>

{{payoff matrix | UL = 5 | UR = 7 | DL = 2 | DR = 9 | Name = Example usage }}

The spaces around the equal signs and before and after the parameters are used only for clarity&nbsp;— they are not needed, and are ignored when the template is evaluated (although this is not the case with unnamed parameters). However parameter names are fully case sensitive&nbsp;— for example, it is not possible to replace "DR" by "dr" or "Dr" in the above example. Parameters with names that are not used by the template are simply ignored.

 

The following points may be worth noting when using templates:

* An unnamed parameter cannot contain an ordinary equals sign, as this would be interpreted as setting off a named parameter. (This does not apply if the equals sign comes within another template call or other item which the parser handles separately.) To pass an equals sign in an unnamed parameter (for example in a [[URL]] with key/value pairs), replace the equals sign with the special template {{tlx|{{=}}}}, which returns an equals sign that will not be specially interpreted. Another method is to replace the unnamed parameter (and any subsequent unnamed parameters) with named parameters&nbsp;— the first unnamed parameter is equivalent to a named parameter with the name "1", and so on. So to call template {{tl|done}} with the parameter "a=b", type either <code><nowiki>{{done|a{{=}}b}}</nowiki></code> or <code><nowiki>{{done|1=a=b}}</nowiki></code>.

* Remember that whitespace characters (spaces, tabs, carriage returns and line feeds) are not automatically stripped from the start and end of unnamed parameters (as they are from named parameters). Including such characters (or any other non-visible characters in any parameters) may in some cases affect the template's behaviour in unexpected ways. (Template designers can use {{tl|StripWhitespace}} to remove unwanted whitespace in unnamed parameters.)

* In documentation and discussions it is often convenient to be able to produce the template call syntax, with a link to the template in question, but without actually calling the template. This can be done easily using the "{{tl|tl}}" template (the ''template link'' template). For example, using the text "<tt><nowiki>{{tl|tc}}</nowiki></tt>" produces "{{tl|tc}}". There is an extended version, {{tl|tlx}}, which also supports parameters.

* When viewing old versions of pages, remember that templates will be transcluded as they are now, not necessarily as they were when the old page version was active.

* To get a list of templates transcluded on a page, click "Edit", and find the list below the edit window. This list also includes the sub-templates used by the templates that are directly transcluded. To get such a list for a page section, an old version of the page, or your newly edited version prior to saving, click "Show preview" on the appropriate edit page. (For an old version, the subtemplate tree will be constructed according to the templates' current state.)

 

 

 

There is no hard rule about what name to choose for a template&nbsp;— make it short but reasonably descriptive. If similar templates exist, try to follow a consistent naming pattern. Templates can be renamed without breaking existing transclusions, provided a redirect to the new template name is left behind.

 

 

 

The values of the parameters which can be fed to a template are represented in the template code by items enclosed between ''triple'' braces:

* the code <code><nowiki>{{{xxx}}}</nowiki></code> will be replaced by the value of the parameter named ''xxx''

Because of the multiple uses of double-brace and triple-brace syntax, expressions can sometimes be ambiguous. It may be helpful or necessary to include spaces to resolve such ambiguity, for example by writing <code><nowiki>{{ {{{xxx}}} }}</nowiki></code> or <code><nowiki>{{{ {{xxx}} }}}</nowiki></code>, rather than typing five consecutive braces. However, watch out for unwanted whitespace appearing in template expansions.

 

 

 

 

{| class="wikitable" style="text-align:center;" width="80%"

|{{#if: {{{param|}}} | Hooray...! | Darn...! }}

|-

|<nowiki>{{#expr: ( pi * 4 ^ 2 ) round 3 }}</nowiki>

|{{#expr: ( pi * 4 ^ 2 ) round 3 }}

|-

|<nowiki>{{#ifexpr: 1.23E+3 mod 2 | Odd | Even }}</nowiki>

|{{#ifexpr: 1.23E+3 mod 2 | Odd | Even }}

The PAGENAME and NAMESPACE variables are particularly useful, and frequently used, to change template behavior based on context. For example, if the template transcludes a category link (e.g. cleanup templates, which transclude a link categorizing the page as a page which needs cleanup), it will often check the NAMESPACE variable to make sure that talk pages, user pages, or anywhere else the tag might incidentally be placed do not themselves get categorized as pages needing cleanup.

 

Templates may contain other templates&nbsp;— this is usually called "nesting". As the template is processed, the wikitext produced by any nested templates is transcluded into the nesting template, so that the final product is essentially processed from the most deeply nested template out. While fairly straightforward in application, it involves some noteworthy quirks and tricks.

 

When a nested template contains unmatched curled-brackets&nbsp;— as in {{tl|lb}}&nbsp;— the unmatched brackets are treated as text during processing, and do not affect the parsing of brackets in the nesting template. If the nested template is substituted, however, the substitution is processed first, and this ''will'' change how braces are parsed in the nesting template. This has little practical use, but can occasionally introduce unexpected errors.

 

 

* <code><nowiki><noinclude>...</noinclude></nowiki></code>&nbsp;— the text between the noinclude tags will not be included when the template is transcluded (substituted)

* <code><nowiki><includeonly>...</includeonly></nowiki></code>&nbsp;— the text between the includeonly tags will be transcluded (substituted), but will not be processed on the template's own page

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

 

* The template {{tl|StripWhitespace}} can be used to strip any initial or final whitespace from unnamed parameter values, if this would cause problems (named parameter values are automatically stripped in this way).

* For debugging templates the following techniques are sometimes helpful:

** using "subst:"&nbsp;— substituting a template (rather than transcluding it) can show more clearly what is happening when the template is transcluded.

** using "msgnw:"&nbsp;— this keyword (short for "message, nowiki") transcludes the wikitext of the template page, more or less, rather than the processed contents. it is not perfect: lists are rendered, comments are removed, and single newlines are replaced with spaces (which is particularly confounding when transcluding wikitext tables).

* Do not use <code>=</code> wikimarkup to create section headers within a template which is intended for use in article space&nbsp;— this will create an [edit] link that when transcluded will confusingly open the template for editing.

 

 

 

 

 

When templates are rendered or expanded to HTML for viewing in your browser, they use memory. This is called the post-expand include size and has a limit of 2,048,000 bytes. This size is included as an invisible comment in the HTML output— use your browser's view source feature to show the raw HTML and search for ''newpp''. The report will look like:

<!--

NewPP limit report

Expensive parser function count: 2/500

-->

 

The example shows that template expansion is using 63k out of 2M of available memory.

 

 

 

{| class="wikitable"

* Introductions:

** [[Transclusion]]

** [[mw:Help:Templates]]

* [[mw:Help:Magic words]]

* [[mw:Help:Extension:ParserFunctions]]

* [[m:Help:Parameter default]]<!-- m: -->

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* [[mw:Manual:$wgEnableScaryTranscluding|Interwiki transclusion]]

* [[mw:Manual:Parser.php]]

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* [{{fullurl:Special:Allpages|namespace=10}} Special:Allpages (namespace 10)] all templates on this server

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* Multilingual portal pages, see [[meta:www]]

* [[m:Spam blacklist]]

|}

 

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