Formula:=xpd=/doc

Subpagina haec est documentatio de Formula:=xpd=.
Hic legitur quomodo uti, ac categoriae, nexus invervici et cetera continentur qui formula in origine non continet.

The expansion demo templates (see [1]) show, for documentation:

some wikitext
its rendering
a link to ExpandTemplates applied to the wikitext; thus it shows:
- The expanded wikitext.
- The rendering of this expanded wikitext

Template:=xpd=/doc selects one of the following four templates based on the number of unnamed parameters

Template:Xpd0 - simplified version of Template:Xpdoc
Template:Xpd1 - simplified version of Template:Xpdopec
Template:Xpd2 - simplified version of Template:Xpdopepec
Template:Xpd3 - simplified version of Template:Xpdopepepec

Separator parameter

The default separator is "gives". With gives={{!}}{{!}} to get "||" for use in a table, the same separator is used before the ExpandTemplates link.

Example:

{| class="wikitable"
!wikitext!!result!!ExpandTemplates
|-
|{{xpd|CURRENTDAY|gives={{!}}{{!}}}}
|-
|{{xpd|1=#expr:2+2|gives={{!}}{{!}}}}
|-
|{{xpdn|#expr: 4*|#expr:not 0|>3|gives={{!}}{{!}}}}
|}

gives

wikitext	result	ExpandTemplates
Formula:xpd
Formula:xpd
Formula:xpdn

Quotes

The quotation marks are needed to see spaces and newlines at the start and end of the result:

Formula:xpd

In other expand demo templates they are also needed to see spaces and newlines at the start and end of the wikitext, and to get a result independent of whether it starts on a line due to parameter {{{gives}}}.

Limitations

This Template:Xpd is a simplified version of some expansion demo templates. If necessary use the proper extended version.

Named parameters and parameter values with equals signs

Named parameters are not supported. Neither are equals signs in parameter values of the template or parser function demonstrated.

Examples:

{{xpd|1x| p{{=}}q }} gives Formula:xpd - wrong result due to the template call in the parameter; is corrected by substitution and putting nowiki tags in the lefthand side (see below), giving {{1x| p{{=}}q }} gives Formula:1x [2].
{{xpd|1x|2= p=q }} gives Formula:xpd - wrong result because the lefthand side would be expanded interpreting p as named parameter, while the righthand side shows the result if the unnamed parameter of 1x has the given value; use {{xpdopec|1x|1|3= p=q }} giving Formula:xpdopec or {{xpdnp|1x|1n=1|1v= p=q }} giving Formula:xpdnp (spaces and newlines are trimmed).
{{xpd|t np|q=s}} gives: Formula:xpd ("q=s" is ignored); instead, use {{xpdopec|t np|q|s}} giving Formula:xpdopec or {{xpdnp|t np|1n=q|1v=s}} giving Formula:xpdnp.

Even in the case of a parser function called with a parameter containing an equals sign the template for named parameters should be used:

{{xpd|#if:x|p=q}} gives: Formula:xpd ("p=q" is ignored); instead, use {{xpdnp|#if:x|1n=p|1v=q}} giving Formula:xpdnp.

Spaces and newlines

If parameters start or end with a space or newline, these are preserved. Even if the left-hand side, as mentioned, does not show the raw wikitext of the parameters but the rendering, the right-hand side gives the correct result.

Example with two newlines, hence also the left-hand side is correct:

Formula:xpdc

Example without consecutive spaces inside a parameter value, hence also the left-hand side is correct:

"Formula:xpdc"

Substitution

{{subst:xpd|substnp=subst:|tc}} gives the wikitext {{xpd0|tc}}
{{subst:xpd|substnp=subst:|t1|p}} gives the wikitext {{xpd1|t1|p}}
{{subst:xpd|substnp=subst:|t2|p|q}} gives the wikitext {{xpd2|t2|p|q}}
{{subst:xpd|substnp=subst:|concat|p|q|r}} gives the wikitext {{xpd3|concat|p|q|r}}

Note that except in the case of long and complicated parameters, adding the number of parameters after "xpd" is easier than adding "subst:" and "|substnp=subst:".

With substitution of xpd1 etc. and putting nowiki tags around the list of parameters the left hand side is given literally without conversions, see also above.