Help:Labeled section transclusion

Labeled Section Transclusion(LST) offers two basic ways to specify a "section" of apagefortransclusion.One way uses the page name and aheading(section title, as seen on the rendered page). The other way enables an arbitrary "section" for transclusion, but it requires markup first in order to add thelabel.

Three functions can transclude a section from a givenpage name.

• {{#section:page name|label}}(a labeled section)
• {{#section-x:page name|label}}(all except that labeled section)
• {{#section-h:page name|heading}}(a normal section)

Note that there are also equivalent names for these functions, the base names being#lst,#lstx,and#lsth.

To prepare an arbitrary "section" for a labeled section transclusion, mark it withbeginandendattributes inside<section />tags that contain yourlabel:

<sectionbegin=label/>and<sectionend=label/>

Compared to LST transclusion,partial transclusionmarkup cannot belabeled,and thus the source page cannot have one set of its sections transcluded to one page while having also a different set for another page. A page marked up with partial transclusion tags only, will always transclude the same. But LST and partial transclusion can work together on the same page.

These LST functions take additional parameters, as explained below.§ Example pagesprovides search links for the articles that currently employ LST so you can see how they are using it.

Functions summary

This section summarizes the three parser functions in the Labeled Section Transclusion extension.

Syntax: {{function:fullpagename|section|range/change}}

Parameter		Parsing entity it identifies
1	Fullpagename	Source page.The only required argument. Type it in, or usevariables like {{FULLPAGENAME}},(but notsubpage linking with../).
2	Section	Label( "labeled section" ), orheading(section title), to transclude. Optional parameter. If a label, it must have been added and saved first.
3	Range	Final sectionin a contiguous series of headings or labels to transclude. Optional. #sectiontranscludes the final section. #section-hdoes not transclude the final section. #section-xdoes not take a range.
3	Change	Replacement wikitext.Only#lstxcan rewrite a labeled section during transclusion. Optional.

It is not possible to passtemplate parametersto the transcluded section or page but the code of the page can usemagic wordslike{{PAGENAME}}to test where it is and behave differently.

Behaviors

Parser Function	Alias	Description
#lst	#section	Transclude alabelfound inside<section />tags. Honors transclusion tags. Default is entire page. If the label is not found, transclude nothing.
#lstx	#section-x	Transclude entire page, butexcludea label. Blind to headings. Honors transclusion tags. Default is entire page. If the label is not found, transclude entire page.
#lsth	#section-h	Transclude aheading(section title). Blind to labels.Does nothonor transclusion tags.†Defaults to the lead section. If the heading is not found, transclude nothing.

†#section-hmakes its target look the same as its source. On thesourcepage

• <noinclude> displays its content
• <onlyinclude> displays its content
• <includeonly>does notdisplay its content

So#section-hmust not render<includeonly>content on thetargetpage.

LST<section/>tags behavior:

• Theendtag is not required. When only abegintag is found, it goes to the end of the page.
• The same label can mark severalbegin/endsections. A range is then everything from the firstbeginto lastend.
• Different labels can overlap. They can also nest.
• Cannot be placed by a transclusion, but instead must be present on the page as saved in the database. See§ No templatebelow.

LST transclusion options:

• It can bepreviewed.
• The target page can be the source pageitself.
• It can be substituted. See§ Substitutionbelow.

Standard syntax applies:

• Generous whitespace is allowed:{{#lst:namespace:pagename|section}}
• An unspaced: colon follows the parser function name.
• In tags no spaces around the = sign of the label (attribute):begin=label
• In tags space is optional before the / slash:<section end=label/>

Common usage errors.

• Template loop detected:preview transcluding a transclusion in the saved version?
• Cite errors. You must have the full definition of anamed referenceon any page that thisList-defined reference(<refname= "X" />) is needed.
• To render transcluding footnotes, you musttag where they go on the page.

Markup

No markup of the source page is needed if only section titles are used to specify the transclusion. This is the case with#section-h.

For labeling a section for LST transclusion use the following markup.

Section marking

Markup your section boundaries in the source page using two, singular,<section/>tags; for example, to label a section "chapter1":

<section begin=chapter1 />this is a chapter<section end=chapter1 />

Note this is not normal opening-tag, closing-tag HTML. In HTML<section>...</section>is invalid. This parser tag,<section />,is incompatible with an HTML element because MediaWiki markup employs a unique parser tag, added just for the Labeled Section Transclusion extension.

Section transclusion

Use the parser function#sectionto transclude the section. For example, to transclude section labeledchapter1from a page calledarticleX:

{{#section:ArticleX|chapter1}}

Transclude the page but exclude the section

To transclude a page, but exclude a specified section, use the#section-xparser function:

{{#section-x:fullpagename|label}}

or

{{#section-x:fullpagename|heading}}

Optionally, you may add replacement text to the excluded section.

{{#section-x:fullpagename|label|replacement text}}

Example:

{{#section-x:articleX|chapter1|See chapter 1 in[[articleX]].}}

The replacement text will appear in the area where the section is skipped (excluded).

Dealing with stray whitespace

By default,#sectionwill include all the whitespace in the section, which can lead to issues if you're trying to transclude the section into a different article. To solve this, make use of the fact that the {{#if}} parser function trims its inputs, e.g.

{{#if:1|{{#section:ArticleX|chapter1}}}}

This will get rid of both leading and trailing whitespace, and the article will render as intended. Because you are nesting templates, it will double thepost-expand include sizeof the excerpt, which can present a problem on longer pages, so you may wish to edit the source page to wrap the content you want to include, without the whitespace, in<onlyinclude>...</onlyinclude>tags instead. You can also use the{{trim}}template instead of {{#if:1}}, but because it is just a wrapper for the {{#if:1}} technique above, it results in a tripling of the post-expand include size.

Other functions

Discontiguous sections

It is possible to have multiple sections with the same name; in this case, every section with that name will be included/excluded. This is especially useful to mark various discussions.

Section ranges

These functions can transclude the whole page, so they have the two, optional argument to specify behaviours: 1) a name-tagged section or heading-title, 2) a range of such named section-tags or section titles, and 3) replacement content for a named section.

• {{#section:articleX|chapter1|chapter3}}includes everything from the beginning of chapter 1 to the end of chapter 3. This allows using empty marker pairs to mark one end of the section, possibly in a template.
• {{#section-h:articleX|chapter1|chapter3}}includes content of chapter1, heading and content of chapter 2.
• {{#section-x:articleX|chapter1|chapter3}}replaces chapter1 heading and content with the word "chapter3".

Substitution

Instead of transcluding every time, to "transclude" once (to copy), usesubstitution:

{{subst:#section...}}

For example to archive oldtalkon your talk page, you can copy it to an archive page, then delete it, all using LST:

1. Put<section begin=archive />at the beginning of the section you want to archive and<section end=archive />at the end. (We use "archive" for the label, but any label will do.). This section can be anywhere, and it can be multiple sections.
2. Save those change to your talk page.
3. Create a new archive page. Put{{subst:#section:User talk:pagename|archive}}.
4. Save that archive page. The old talk is copied over to it. The transclusion disappears because it was substituted.
5. Edit your talk page again. Replace all the wikitext on the entire page with{{subst:#section-x:User talk:username|archive}}.Thedatabase pagewill be transcluded, minus the exact same wikitext in the saved archive, and minus the section tags (which we had labeled "archive" ).

When using substitution to transclude content on Wikipedia, please use the edit summary to applyreusers' rights and obligations.This applies to any substantial content, and not just article contents.

No template

Currently, no template can facilitate this LST markup because it is necessary to use #tag in order to"preSaveTransform"magic words inside a tag of any kind. For the proper attempt see (the non-functioning){{section}}.

The only way toevaluatetemplate argumentsinside a tag(because of the parsing order) is#tag.LST would need (template) evaluation of the label as the section tag is generated:

{{#tag:section|{{{1}}}}}

But #tag only producesXML-like (balanced, open-closed, start-end, pairs of) tags, while LST will use a singular, explicitly self closing, tag. So LST tags cannot be generated by any template. Compare actual (only in effect) output:

{{#tag:section|content|begin=label}} →
<section begin=label>content</section>N

Tracked inPhabricator
Task T39256

with the requested output:

<section begin=label/>content<section end=label/>

Example pages

These aresearchesstored in a link:

• insource: "section h" insource:/\# "section-h" /(Articles)
• insource:section insource:/\{\{\#section/(Articles)
• all: insource: "section x" insource:/\# "section-x" /(entire wiki)
• insource:lst insource:/\#lst/(Articles)
• insource:lsth insource:/\{\{\#lsth/(Articles)
• all: insource:lstx insource:/\#lstx/(entire wiki)

See also

• Help:TRANSSECTION
• mw:Extension:Labeled Section Transclusion
• Wikipedia:Cascading content
• Help:Transclusion#Drawbacks

Templates

• {{Excerpt}}
• {{Section transclude}}
• {{R}}- a referencing/citation template optionally taking advange of labeled section transclusion to mark context sections