Help:Extension:CodeMirror

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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 " Syntax" 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

These keyboard shortcuts do not apply to the 2017 editor, which has its own set of keyboard shortcuts. Those can be reviewed by pressing Ctrl+/ while the editor is open.

List of 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 code.
`Ctrl`+`⇧ Shift`+`]`	`⌘ Command`+`Alt`+`]`	Unfold the selected code.
`Ctrl`+`Alt`+`[`	`Ctrl`+`Alt`+`[`	Fold all code.
`Ctrl`+`Alt`+`]`	`Ctrl`+`Alt`+`]`	Unfold all code.
`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.
`Ctrl`+`⇧ Shift`+`X`	`⌘ Command`+`⇧ Shift`+`X`	Toggle viewing the editor in right-to-left and left-to-right.
`Ctrl`+`⇧ Shift`+`,`	`⌘ Command`+`⇧ Shift`+`,`	Open the CodeMirror preferences panel.

Features

CodeMirror preferences

MediaWiki version:

≥ 1.44

This feature is not available for the 2017 editor.

Most features documented here can be disabled or enabled by individual users. To open the preferences panel, press Ctrl+⇧ Shift+, (or ⌘ Command+⇧ Shift+, on MacOS). If you use WikiEditor , you can also get to your CodeMirror preferences by clicking on the button in the "Advanced" section of the toolbar. Your CodeMirror preferences will be remembered across different devices and sessions.

Bracket matching

When the cursor lies directly next to a bracket, the feature highlights the corresponding matching bracket.

Code folding

MediaWiki version:

≥ 1.43

This feature is not available for the 2017 editor.

Code folding on w:Barack Obama.

Code folding allows you to fold template parameters, extension tags, and other code blocks. This can make managing large, complex templates considerably easier.

Usage

When a cursor or selection covers any part of supported syntax, a tooltip icon will appear just above the text. Clicking it will fold the code, leaving only the template or tag name.

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

Keyboard shortcuts
Shortcut	Shortcut (macOS)	Description
`Ctrl`+`⇧ Shift`+`[`	`⌘ Command`+`Alt`+`[`	Fold the selected code.
`Ctrl`+`⇧ Shift`+`]`	`⌘ Command`+`Alt`+`]`	Unfold the selected code.
`Ctrl`+`Alt`+`[`	`Ctrl`+`Alt`+`[`	Fold all code.
`Ctrl`+`Alt`+`]`	`Ctrl`+`Alt`+`]`	Unfold all code.

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:^[1]

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

Autocompletion

MediaWiki version:

≥ 1.44

This feature is not available for the 2017 editor.

Example showing autocompletion of parser functions.

This feature provides autocompletion of magic words , parser extension tags , and URL protocols. If you enter {{#, you should see a list of all parser functions that start with #. Similarly, typing double underscores (__) will show a list of double-underscored magic words. You can continue to type to narrow your search. Use the arrow keys to select the desired text, and hit the ↵ Enter or Tab ↹ key to make your selection. Autocompletion does not work for templates, or for magic words or parser functions that do not begin with # or __.

Opening links in wikitext

You can quickly open links specified in the wikitext. Do this by holding down the Ctrl key (or ⌘ Command on MacOS) and clicking on a page title inside of link syntax, such as [[Main Page]]. Clicking this case would open Main Page in a new tab.

This feature also works for template names and file names.

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.^[2]

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

Highlight the active line

MediaWiki version:

≥ 1.44

This feature is not available for the 2017 editor.

In your CodeMirror preferences, you can select "Highlight the active line" to enable this feature, which can make it easier to tell which line of text the cursor is on, especially on large pages.

Line wrapping

MediaWiki version:

≥ 1.44

This feature is not available for the 2017 editor.

Line wrapping is the default behaviour in most editors. Sometimes you may want to disable this, especially when writing complex wikitext or other code. You can disable line wrapping in your CodeMirror preferences.

Multiple cursors and selections

This feature is not available for the 2017 editor.

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.

Highlight special characters

This feature is not available for the 2017 editor.

By default, CodeMirror will highlight non-printable control characters and other characters such as non-breaking spaces. Control characters appear as a red dot, while non-breaking spaces are displayed as a faint gray dot. Hovering over these characters will show a tooltip stating which character it is.

If desired, you can disable this feature in your CodeMirror preferences.

Colorblind mode

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

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.^[1] 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
.cm-mw-skipformatting	leading space	foo bar
.cm-mw-list	asterisk or number sign	* foo bar, # foo bar
.cm-mw-signature, .cm-mw-hr	signature, horizontal rule	∼∼∼∼, ----
.cm-mw-indenting	colons	::: foo bar
.cm-mw-html-entity	HTML entities	&
.cm-mw-comment	HTML comment	<!-- comment -->
.cm-mw-apostrophes-bold, .cm-mw-apostrophes-italic	bold and italic	'''bold''' ''italic''
Headings
.cm-mw-section-1	level 1 heading^[3]	= Heading =
.cm-mw-section-2	level 2 heading^[3]	== Heading ==
.cm-mw-section-3	level 3 heading	=== Heading ===
.cm-mw-section-4	level 4 heading	==== Heading ====
.cm-mw-section-5	level 5 heading	===== Heading =====
.cm-mw-section-6	level 6 heading	====== Heading ======
.cm-mw-section-header	equal signs	==
Templates
example		{{cite book\|title=foo bar}}
.cm-mw-template	other template content	foo bar
.cm-mw-template-name	template name	cite book
.cm-mw-template-argument-name	template parameters	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}}}
.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>
.cm-mw-exttag	text inside tags	string
.cm-mw-exttag-name, .cm-mw-ext-poem^[4]	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>
Pre-formatted text
.cm-mw-tag-pre	pre-formatted text	<pre>foo bar</pre>
.cm-mw-tag-nowiki	nowiki text	<nowiki>foo bar</nowiki>
Internal links
example		[[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]
.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 \|}
.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__
.cm-mw-list	semicolon (definition lists)	;Foo:Bar
.cm-special-char-nbsp	non-breaking space	· ·
.cm-specialChar	control characters	•

Notes

↑ ^1.0 ^1.1 Your personal CSS is at Special:MyPage/common.css. You can also make your changes take effect globally if GlobalCssJs is installed. On Wikimedia wikis, your global CSS is at meta:Special:MyPage/global.css.
↑ Controlled by the $wgCodeMirrorLineNumberingNamespaces configuration setting. See Extension:CodeMirror#Configuration for more information.
↑ ^3.0 ^3.1 The size is not changed in the 2017 wikitext editor.
↑ Where "poem" is the name of the tag.

[personal-css-1] 1.0 ^1.1 Your personal CSS is at Special:MyPage/common.css. You can also make your changes take effect globally if GlobalCssJs is installed. On Wikimedia wikis, your global CSS is at meta:Special:MyPage/global.css.

[2] Controlled by the $wgCodeMirrorLineNumberingNamespaces configuration setting. See Extension:CodeMirror#Configuration for more information.

[ve-we-sizing-3] 3.0 ^3.1 The size is not changed in the 2017 wikitext editor.

[4] Where "poem" is the name of the tag.

[1]

[2]

[3]

[4]