Help:Transclusion: Difference between revisions

Line 56:

{{for|a quick guide to templates|Help:A quick guide to templates}}

The most common application of transclusion is the transclusion of [[Help:Template|templates]]. Templates are pages that are written with the prime objective of being included in other pages, either through transclusion or [[Help:Substitution|substitution]]. As shown above, the usual syntax for transcluding a template titled Template:Pagename is <syntaxhighlight lang="wikitext" inline>{{Pagename}}</syntaxhighlight>. However, some templates can also use [[parameter]]s. Parameters are [[Variable (computer science)|variables]] that can be given values (also termed [[Parameter_(computer_programming)#Parameters_and_arguments|arguments]]) that can be passed on to certain templates in order for them to work in different ways. Templates can either use no parameters, a fixed number of parameters, or a variable number of parameters. The number of parameters a template can use is from one upwards.

The most common application of transclusion is the transclusion of [[Help:Template|templates]]. Templates are pages that are written with the prime objective of being included in other pages, either through transclusion or [[wikipedia:Help:Substitution|substitution]]. As shown above, the usual syntax for transcluding a template titled Template:Pagename is <syntaxhighlight lang="wikitext" inline>{{Pagename}}</syntaxhighlight>. However, some templates can also use [[parameter]]s. Parameters are [[Variable (computer science)|variables]] that can be given values (also termed [[Parameter_(computer_programming)#Parameters_and_arguments|arguments]]) that can be passed on to certain templates in order for them to work in different ways. Templates can either use no parameters, a fixed number of parameters, or a variable number of parameters. The number of parameters a template can use is from one upwards.

The exact syntax for using parameters with templates can vary greatly, depending on the actual template being used. But, for an example template titled Template:Pagename, which happened to use three parameters, the general form would be:

Line 72:

===Substitution===

[[Help:Substitution|Substitution]] has a similar double curly-bracket syntax, and its action is similar to transclusion. When you preview a page with substitution wikitext in it, its action is identical to transclusion. But when you save a page with substitution wikitext in it, it differs in that it substitutes that wikitext with the actual wikitext of the template.

[[wikipedia:Help:Substitution|Substitution]] has a similar double curly-bracket syntax, and its action is similar to transclusion. When you preview a page with substitution wikitext in it, its action is identical to transclusion. But when you save a page with substitution wikitext in it, it differs in that it substitutes that wikitext with the actual wikitext of the template.

For example, when <syntaxhighlight lang="wikitext" inline>{{subst:Like}}</syntaxhighlight> is saved, it would substitute that wikitext with the actual wikitext from the [[Template:Like]]. In practice, the main difference that this makes is that if an update happened to the wikitext of the Template:Like, it would not update any pages where <syntaxhighlight lang="wikitext" inline>{{subst:Like}}</syntaxhighlight> had already been saved.