User:BrandonXLF/Help:Infinite parameters

Wikitext does not have support for infinite parameters, so templates that use infinite parameters make use of Lua modules.

Custom modules

One way to support infinite parameters is to write a custom Lua modules that implements the template. This is done by modules like Module:Jct, Module:Infobox, Module:List, and Module:Template link general. There are many different strategies for supporting infinite parameters in Lua, some of which are demonstrated below. Also check out modules like Module:TableTools for working with Lua tables.

Using ipairs

local p = {}

function p.main(frame)
    local args = frame:getParent().args
    local out = ''

    for i, v in ipairs(args) do
        if out then out = out .. ', ' end
        out = out .. i .. ' is ' .. v
    end

    return out
end

return p

When a template with {{#invoke:__MODULE__|main}} is called with {{__TEMPLATE__|A|B|c}}, the output 1 is A, 2 is B, 3 is C would be produced.

Using while

local p = {}

function p.main(frame)
    local args = frame:getParent().args
    local out = ''
    local i = 1

    while args['prefix' .. i] do
        if out then out = out .. ', ' end
        out = out .. 'prefix' .. i .. ' is ' .. v
        i = i + 1
    end

    return out
end

return p

When a template with {{#invoke:__MODULE__|main}} is called with {{__TEMPLATE__|prefix1=A|prefix2=B|prefix3=c}}, the output 1 is A, 2 is B, 3 is C would be produced.

Using metamodules

If you'd like to avoid writing an entire Lua module, there are metamodules that exist to help aid in adding infinite parameter support for functions.

Arbitrary wikitext

These modules work by taking wikitext in <nowiki>...</nowiki> and expanding it while passing it the appropriate parameters.

Unnamed parameters

Module:For nowiki

__TEMPLATE__:

{{#invoke:For nowiki|template|<br>|<nowiki><code>{{{i}}}</code> is {{2x|{{{1}}}|, }}</nowiki>}}

{{__TEMPLATE__|A|B|C}}

produces

1 is A, A 2 is B, B 3 is C, C

Module:ArgRest

__TEMPLATE__:

{{#if:{{{1|}}}|<code>1</code> is {{2x|{{{1}}}|, }}}}{{#invoke:ArgRest|main|<nowiki><br><code>?</code> is {{2x|{{{2}}}|, }}</nowiki>|2}}

{{__TEMPLATE__|A|B|C}}

produces

1 is A, A ? is B, B ? is C, C

Module:Params

__TEMPLATE__:

{{#invoke:Params|setting|i|<br>|sequential|for_each|<code>$#</code> is {{2x|$@|, }}}}

{{__TEMPLATE__|A|B|C}}

produces

1 is A, A 2 is B, B 3 is C, C

Named parameters

Module:For nowiki

__TEMPLATE__:

{{#invoke:For nowiki/sandbox|template|prefix=item|<br>|
<nowiki><code>item{{{i}}}</code> is {{{1}}}{{#if:{{{extra{{{i}}}|}}}|{{sp}}and <code>extra{{{i}}}</code> is {{{extra{{{i}}}}}}}}</nowiki>}}

{{__TEMPLATE__ | item1 = A | extra1 = Apple | item2 = B | extra2 = Orange | item3 = C }}

produces

Module:ArgRest

__TEMPLATE__:

{{#if:{{{item1|}}}|<code>item1</code> is {{{item1}}}{{#if:{{{extra1|}}}|{{sp}}and <code>extra1</code> is {{{extra1}}}}}}}{{#invoke:ArgRest|main|<nowiki><br><code>item?</code> is {{{item2}}}{{#if:{{{extra2|}}}|{{sp}}and <code>extra?</code> is {{{extra2}}}}}</nowiki>|item2}}

{{__TEMPLATE__ | item1 = A | extra1 = Apple | item2 = B | extra2 = Orange | item3 = C }}

produces

item1 is A and extra1 is Apple item? is B and extra? is Orange item? is C

Module:Params

__TEMPLATE__:

{{#invoke:params|setting|i|<br>|all_sorted|call_for_each_group|__CHILD_TEMPLATE__}}

__CHILD_TEMPLATE__:

<code>item?</code> is {{{item}}}{{#if:{{{extra|}}}|{{sp}} and <code>extra?</code> is {{{extra}}}}}

{{__TEMPLATE__ | item1 = A | extra1 = Apple | item2 = B | extra2 = Orange | item3 = C }}

produces

item? is A and extra? is Apple item? is B and extra? is Orange item? is C

Fixed output format

Unnamed parameters

Module:Separated entries

__TEMPLATE__:

{{#invoke:Separated entries|main|separator= also |conjunction= and finally }}

{{__TEMPLATE__|A|B|C}}

produces

A also B and finally C

Module:Enumerate

__TEMPLATE__:

{{#invoke:Enumerate|main}}

{{__TEMPLATE__|A|B|C}}

produces

A B C

Named parameters

Module:Enumerate

__TEMPLATE__:

{{#invoke:Enumerate|main|item}}

{{__TEMPLATE__|item1=A|item2=B|item3=C}}

produces

A B C

See also

• Category:Template metamodules