Help:Extension:CodeMirror

The CodeMirror extension provides syntax highlighting in wikitext editors. This can make editing easier by using colors and shading to visually separate plain text from links, templates, and other wikitext markup.

Usage

Enabling

CodeMirror can be enabled by setting "Enable syntax highlighting for wikitext" in your preferences. In WikiEditor (also known as the 2010 editor, enabled with the "Enable the editing toolbar" preference), it can also be toggled on and off using the highlighter button in the toolbar. In the 2017 editor, you can toggle CodeMirror by clicking the "Page options" button in the toolbar, then selecting "Syntax highlighting".

Keyboard shortcuts

Shortcut	Shortcut (macOS)	Description
Alt+←	Ctrl+←	Move the cursor one word to the left.
Alt+→	Ctrl+→	Move the cursor one word to the right.
Alt+↑	Alt+↑	Move the selected lines up one line.
Alt+↓	Alt+↓	Move the selected lines down one line.
⇧ Shift+Alt+↑	⇧ Shift+Alt+↑	Duplicate the selected lines and keep the selection on the top copy.
⇧ Shift+Alt+↓	⇧ Shift+Alt+↓	Duplicate the selected lines and keep the selection on the bottom copy.
Escape	Escape	Reduce multiple selections to the main range, or to a cursor if there is only one selection.
Ctrl+↵ Enter	⌘ Command+↵ Enter	Insert a blank line below the current line.
Ctrl+[	⌘ Command+[	Remove indentation from the selected lines.
Ctrl+]	⌘ Command+]	Add indentation to the selected lines.
Ctrl+⇧ Shift+[	⌘ Command+Alt+[	Fold the currently selected templates.
Ctrl+⇧ Shift+]	⌘ Command+Alt+]	Unfold the any folded templates in the selection.
Ctrl+Alt+[	Ctrl+Alt+[	Fold all templates on the page.
Ctrl+Alt+]	Ctrl+Alt+]	Unfold all templates that are currently folded.
Ctrl+f	⌘ Command+f	Open the search panel.
Ctrl+g	⌘ Command+g	Find the next occurrence of the search string.
⇧ Shift+Ctrl+g	⇧ Shift+⌘ Command+g	Find the previous occurrence of the search string.
Ctrl+d	⌘ Command+d	Select the next occurrence of the current selection or word, creating multiple selections.
Ctrl+click	⌘ Command+click	Add an additional cursor or selection to the area clicked.

Features

These features are planned to be customizable on a per-user basis. See task T359498.

Bracket matching

Bracket matching

This feature highlights the innermost pair of brackets when the cursor lies between any bracket pair. When the cursor lies directly next to a bracket, the feature highlights the corresponding matching bracket.

Template folding

MediaWiki version:

≥ 1.43

Template folding on w:Barack Obama.

Template folding is a form of code folding for templates in wikitext. It allows you to hide all parameters and their values, showing only the template name. This can make managing large, complex templates considerably easier.

Usage

When a cursor or selection covers any part of template syntax, a tooltip icon will appear just above the text. Clicking it will fold all parameters and values of the template, leaving only the template name.

Folded templates will have the template name followed by the ellipsis icon . Clicking on it will unfold the template back to its original state.

Keyboard shortcuts

Shortcut	Shortcut (macOS)	Description
Ctrl+⇧ Shift+[	⌘ Command+Alt+[	Fold the currently selected templates.
Ctrl+⇧ Shift+]	⌘ Command+Alt+]	Unfold the any folded templates in the selection.
Ctrl+Alt+[	Ctrl+Alt+[	Fold all templates on the page.
Ctrl+Alt+]	Ctrl+Alt+]	Unfold all templates that are currently folded.

Availability

Template folding is currently only deployed on specific wikis and for specific namespaces on Wikimedia wikis. It will be available broadly to everyone as an opt-in feature after we offer preferences (task T359498).

Customization

If you'd like to keep the keyboard shortcut for folding templates, but hide the visual component, you can do so by adding the following to your personal CSS:

.cm-tooltip-fold {
	display: none;
}

Line numbering

Note how the line numbering knew to account for the lines contained in the collapsed templates.

When enabled, line numbers are automatically displayed in all editors. On the Wikimedia wikis, it is only enabled for specific namespaces of specific wikis.

It will be available broadly to everyone as an opt-in feature after we offer preferences (task T359498). Additionally, we'll have an option to highlight the active line, which is useful when editing code.

Line numbers will take into account any hidden lines, such as those through template folding.

Multiple cursors and selections

You can add additional cursors or selections by holding the Ctrl key (or ⌘ Command on MacOS) and clicking on the desired content or cursor placement. After doing so, any changes you make will be applied to all the selections at the same time.

You can also press Ctrl+d (or ⌘ Command+d on MacOS) to select the next occurrence of the current selection or word, which create multiple selections. This can be useful as a quick find and replace feature.

Colorblind mode

See also: meta:WMDE Technical Wishes/Improved Color Scheme of Syntax Highlighting

For users who have difficulty distinguishing between colors, CodeMirror offers a colorblind-friendly mode. This feature can be activated on wikis with CodeMirror enabled with "Enable colorblind-friendly scheme for syntax highlighting when editing wikitext" in your preferences.

With the colorblind-friendly scheme active, the colors of the following page elements change:

Headings, symbols, signatures, section names, magic words	#E4A400
Templates	#9C3A00
HTML tags, references, mathematical expressions	#56B4E9
Variables	#009E73

In addition, background highlights and colors are removed from all text and objects. Bolding and underlining behavior remains unaffected.

Bidi isolation

This feature is currently a work-in-progress. See phab:T358804 for more information.

On right-to-left pages, CodeMirror can isolate HTML and other tags as bidirectional text, which can improve readability. The standard algorithm for the layout of text places neutral punctuation characters between right-to-left text on the wrong side. With bidi isolation, we can correct this so it reads more legibly:

CodeMirror without bidi isolation

CodeMirror with bidi isolation

Color and style customization

This is a partial list of the CodeMirror CSS classes. The complete list of default CodeMirror styling definitions is on Gerrit.

The colors and styles used in CodeMirror can be overridden by defining your own styles for the classes in the table below in your personal CSS. Please be aware that changing some things like the line height or font size may not work in the 2017 wikitext editor.

CSS class(es)	Element	CodeMirror styling	WikEd styling	Rememberthedot's styling
.cm-mw-skipformatting	leading space	foo bar	foo bar
.cm-mw-list	asterisk or number sign	* foo bar, # foo bar	* foo bar # foo bar	* foo bar # foo bar
.cm-mw-signature, .cm-mw-hr	signature, horizontal rule	∼∼∼∼, ----	~~~~, ----	~~~~, ----
.cm-mw-indenting	colons	::: foo bar	::: foo bar	::: foo bar
.cm-mw-html-entity	HTML entities	&	&	&
.cm-mw-comment	HTML comment	<!-- comment -->	<!-- comment -->	<!-- comment -->
.cm-mw-apostrophes-bold, .cm-mw-apostrophes-italic	bold and italic	'''bold''' ''italic''	'''bold''' ''italic''	'''bold''' ''italic''
Headings
.cm-mw-section-1	level 1 heading	= Heading =	= Heading =	= Heading =
.cm-mw-section-2	level 2 heading	== Heading ==	== Heading ==	== Heading ==
.cm-mw-section-3	level 3 heading	=== Heading ===	=== Heading ===	=== Heading ===
.cm-mw-section-4	level 4 heading	==== Heading ====	==== Heading ====	==== Heading ====
.cm-mw-section-5	level 5 heading	===== Heading =====	===== Heading =====	===== Heading =====
.cm-mw-section-6	level 6 heading	====== Heading ======	====== Heading ======	====== Heading ======
.cm-mw-section-header	equal signs	==
Templates
example		{{cite book|title=foo bar}}	{{cite book|title=foo bar}}	{{cite book|title=foo bar}}
.cm-mw-template	other template content	foo bar
.cm-mw-template-name	template name	cite book	cite book
.cm-mw-template-argument-name	template parameters	title=	title=
.cm-mw-template-delimiter	pipe	|	|
.cm-mw-template-bracket	opening/closing brackets	{{ }}	{{ }}
.cm-mw-template-ground .cm-mw-template2-ground .cm-mw-template3-ground	whole template (the number is the level of nesting)	{{foo|{{cite book|title=foo bar}}}}
Variables
example		{{{foo|bar}}}	{{{foo|bar}}}	{{{foo|bar}}}
.cm-mw-templatevariable	variable	bar
.cm-mw-templatevariable-name	triple-braced variable name	foo
.cm-mw-templatevariable-bracket	opening/closing brackets	{{{ }}}
.cm-mw-templatevariable-delimiter	pipe	|
Parser functions
example		{{#assessment: A | High }}
.cm-mw-parserfunction	parser function parameters	High
.cm-mw-parserfunction-name	parser function name	PAGENAME #invoke
.cm-mw-parserfunction-bracket	opening/closing brackets	{{ }}
.cm-mw-parserfunction-delimiter	delimiter	:
Extension tags
Note: Extension may use their own styles and rules for highlighting text within the extension tag.
example		<poem style="padding: 1em;">string whole line string</poem>	<ref name="foo"> </ref>	<tag>...</tag>
.cm-mw-exttag	text inside tags	string
.cm-mw-exttag-name, .cm-mw-ext-poem	tag name	poem
.cm-mw-exttag-bracket	opening/closing brackets	< >
.cm-mw-exttag-attribute	reference attributes	style="padding: 1em;"
HTML tags
example		<span style="foo">foo bar</span>
.cm-mw-htmltag-name	HTML tag	span
.cm-mw-htmltag-bracket	opening/closing brackets	< >
.cm-mw-htmltag-attribute	parameters and values	style="foo"
	superscript subscript	foo<sup>bar</sup> foo<sub>bar</sub>	Foo<sup>bar</sup> Foo<sub>bar</sub>
Pre-formatted text
.cm-mw-tag-pre	pre-formatted text	<pre>foo bar</pre>	<pre>foo bar</pre>	<tag>foo bar</tag>
.cm-mw-tag-nowiki	nowiki text	<nowiki>foo bar</nowiki>	<nowiki>foo bar</nowiki>	<tag>foo bar</tag>
Internal links
example		[[foo bar]] [[foo#section|bar]]	[[foo bar]] [[foo#section|bar]]	[[foo bar]] [[foo#section|bar]]
.cm-mw-link-pagename	internal link target	foo bar
.cm-mw-link	# character	#section
.cm-mw-link-tosection	characters after the #	#section
.cm-mw-link-bracket	opening/closing brackets	[[ ]]
.cm-mw-link-text	link label	(no additional formatting)
.cm-mw-link-delimiter	pipe	|
.cm-mw-pagename	internal link targets	foo bar
External links
example		https://www.example.org [https://www.example.org] [https://www.example.org example.org]	https://www.example.org [https://www.example.org] [https://www.example.org example.org]	https://example.org [https://example.org] [https://example.org example.org]
.cm-mw-extlink, .cm-mw-free-extlink	external link target	www.example.org
.cm-mw-extlink-protocol, .cm-mw-free-extlink-protocol	protocol	https://
.cm-mw-extlink-text	link label	(no additional formatting)
.cm-mw-extlink-bracket	opening/closing brackets	[ ]
Tables
example		{| class="wikitable" |- ! Header text !! Header text |- | Example || Example |}	{| class="wikitable" |- ! Header text !! Header text  |- | Example || Example  |}	{| class="wikitable" |- ! Header text !! Header text |- | Example || Example |}
.cm-mw-table-bracket	opening/closing brackets and pipe	{| |}
.cm-mw-table-delimiter	row and column separators	| |- !
.cm-mw-table-definition	table classes and styles	class="wikitable"
.cm-mw-table-caption	caption text	|+ caption
Other
.cm-mw-double-underscore	magic words	__TOC__	__TOC__
.cm-mw-list	semicolon (definition lists)	;Foo:Bar
.cm-special-char-nbsp	non-breaking space	· ·
.cm-specialChar	control characters	•