Module:DecodeEncode

Implements Lua functions mw.text.decode, mw.text.encode in a module.

{{#invoke:decodeEncode|decode|s=Source text©}} → Source text©

See List of XML and HTML character entity references.

Decode (© → ©)

See § Known issues for possible THIN SPACE, epsilon issues

Decodes Named Entities from entity name into a regular (unicode) character:

© → ©

> → >

All welldefined named entities are decoded (HTML Named character references, formally: as defined in the PHP table).

A regular, rendered sentence:

"At 100 °F, & with a "burning" sun above, we , we ⁄walked⁄."

In code:

"At 100 °F, & with a "burning" sun above, we ⁄walked⁄." -- wikitext

Processing:

{{#invoke:decodeEncode|decode|s=At 100 °F, & with a "burning" sun above, we ⁄walked⁄.}} →

At 100 °F, & with a "burning" sun above, we ⁄walked⁄. -- In code: straight characters, no named entities.

Renders, again:

"At 100 °F, & with a "burning" sun above, we ⁄walked⁄."

Decode a reduced set only

By setting |subset_only=true, only these five entity names are decoded: '&lt;', '&gt;', '&amp;', '&quot;', '&nbsp;' (that is, into '<', '>', '&', '"', ' ').

Note: There is a difference with the relevant Lua parameter. (This only concerns your task if you also work directly with the Lua mw.text.decode function). Lua documentation defines parameter |decodeNamedEntities=, having this effect: when omitted or false, only the reduced set of entities is recognized and decoded. This use of 'false' is inverted in using |subset_only=: |decodeNamedEntities=false = |subset_only=true.

Also, this module ignores the "omitted" logic: |subset_only= should be set explicitly to 'true' to be effective.

Encode (© → &copy;)

Function encode encodes some entity-named characters into that name (for example: & → &).

Regular sentence:

"At >100 °F, & with a "burning" sun above, we walked. ©"

In code:

"At >100 °F, & with a "burning" sun above, we walked. ©"

Encode:

{{#invoke:decodeEncode|encode|s=At >100 °F, & with a "burning" sun above, we walked. ©|charset=&<>{{!}}°"'&©}}

→

At >100 °F, & with a "burning" sun above, we walked. ©

Renders as:

"At >100 °F, & with a "burning" sun above, we walked. ©"

character set to encode

Per Lua documentation, only a small set of characters is processed. The characterset can be set (expanded) by using |charset=.

Example: |charset=<>" \'& (the default), |charset=<>°"'&©{{!}}; characters not in the default will be replaced by their decimal entity: © → © (hexadecimal number, not decimal nor named &copy;)

Known issues

• 13 Sep 2021: NOTE: The encode function with user-supplied charset is now used productively in {{R/superscript}} and {{R/ref}}. Before implementing breaking changes here, these templates need to be adjusted accordingly!

• 26 Sep 2021: U+2009   THIN SPACE (HTML  ·  )

Note: Possible bug: Decoding   works, but   doesn't.

Resolved in code.

• 4 Feb 2023: U+03B5 ε GREEK SMALL LETTER EPSILON (HTML ε· ε)

Tracked in Phabricator
Task T328840

See :w:Module talk:DecodeEncode § Bug report: bad decoding of U+03B5 ε (epsilon)

Resolved in code.

See also

• mw.text.decode
• mw.text.encode
• Module:Urldecode

---

require('strict')
local p = {}

local function _getBoolean( boolean_str )
	-- from: module:String; adapted
	-- requires an explicit true
	local boolean_value

	if type( boolean_str ) == 'string' then
		boolean_str = boolean_str:lower()
		if boolean_str == 'true' or boolean_str == 'yes' or boolean_str == '1' then
			boolean_value = true
		else
			boolean_value = false
		end
	elseif type( boolean_str ) == 'boolean' then
		boolean_value = boolean_str
	else
		boolean_value = false
	end
	return boolean_value
end

function p.decode( frame )
	local s = frame.args['s'] or ''
	local subset_only = _getBoolean(frame.args['subset_only'] or false)

	return p._decode( s, subset_only )
end

function p._decode( s, subset_only )
	-- U+2009 THIN SPACE: workaround for bug: HTML entity   is decoded incorrect. Entity   gets decoded properly
	s = mw.ustring.gsub( s, ' ', ' ' )
	-- U+03B5 ε GREEK SMALL LETTER EPSILON: workaround for bug (phab:T328840): HTML entity ε is decoded incorrect for gsub(). Entity ε gets decoded properly
	s = mw.ustring.gsub( s, 'ε', 'ε' )

	local ret = mw.text.decode( s, not subset_only )

	return ret
end

function p.encode( frame )
	local s = frame.args['s'] or ''
	local charset = frame.args['charset']

	return p._encode( s, charset )
end

function p._encode( s, charset )
	-- example: charset = '_&©−°\\\"\'\=' -- do escape with backslash not %;
	local ret

	if charset and charset ~= '' then
		ret = mw.text.encode( s, charset )
	else
		-- use default: chartset = '<>&"\' ' (outer quotes = lua required; space = NBSP)
		ret = mw.text.encode( s )
	end 
	
	return ret
end

return p