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<!doctype html> <title>CodeMirror: User Manual</title> <meta charset="utf-8"/> <link rel=stylesheet href="docs.css"> <script src="activebookmark.js"></script> <script src="../lib/codemirror.js"></script> <link rel="stylesheet" href="../lib/codemirror.css"> <script src="../addon/runmode/runmode.js"></script> <script src="../addon/runmode/colorize.js"></script> <script src="../mode/javascript/javascript.js"></script> <script src="../mode/xml/xml.js"></script> <script src="../mode/css/css.js"></script> <script src="../mode/htmlmixed/htmlmixed.js"></script> <style> dt { text-indent: -2em; padding-left: 2em; margin-top: 1em; } dd { margin-left: 1.5em; margin-bottom: 1em; } dt {margin-top: 1em;} dd dl, dd dt, dd dd, dd ul { margin-top: 0; margin-bottom: 0; } dt + dt { margin-top: 0; } dt.command { position: relative; } span.keybinding { position: absolute; right: 0; font-size: 80%; color: #555; text-indent: 0; } </style> <div id=nav> <a href="http://codemirror.net"><h1>CodeMirror</h1><img id=logo src="logo.png"></a> <ul> <li><a href="../index.html">Home</a></li> <li><a href="#overview" class=active data-default="true">Manual</a></li> <li><a href="https://github.com/codemirror/codemirror">Code</a></li> </ul> <ul> <li><a href="#usage">Basic Usage</a></li> <li><a href="#config">Configuration</a></li> <li><a href="#events">Events</a></li> <li><a href="#keymaps">Key maps</a></li> <li><a href="#commands">Commands</a></li> <li><a href="#styling">Customized Styling</a></li> <li><a href="#api">Programming API</a> <ul> <li><a href="#api_constructor">Constructor</a></li> <li><a href="#api_content">Content manipulation</a></li> <li><a href="#api_selection">Selection</a></li> <li><a href="#api_configuration">Configuration</a></li> <li><a href="#api_doc">Document management</a></li> <li><a href="#api_history">History</a></li> <li><a href="#api_marker">Text-marking</a></li> <li><a href="#api_decoration">Widget, gutter, and decoration</a></li> <li><a href="#api_sizing">Sizing, scrolling, and positioning</a></li> <li><a href="#api_mode">Mode, state, and tokens</a></li> <li><a href="#api_misc">Miscellaneous methods</a></li> <li><a href="#api_static">Static properties</a></li> </ul> </li> <li><a href="#addons">Addons</a></li> <li><a href="#modeapi">Writing CodeMirror Modes</a></li> <li><a href="#vimapi">Vim Mode API</a> <ul> <li><a href="#vimapi_configuration">Configuration</a></li> <li><a href="#vimapi_extending">Extending VIM</a></li> </ul> </li> </ul> </div> <article> <section class=first id=overview> <h2 style="position: relative"> User manual and reference guide version 5.18.2 </h2> CodeMirror is a code-editor component that can be embedded in Web pages. The core library provides only the editor component, no accompanying buttons, auto-completion, or other IDE functionality. It does provide a rich API on top of which such functionality can be straightforwardly implemented. See the <a href="#addons">addons</a> included in the distribution, and the <a href="https://github.com/codemirror/CodeMirror/wiki/CodeMirror-addons">list of externally hosted addons</a>, for reusable implementations of extra features. CodeMirror works with language-specific modes. Modes are JavaScript programs that help color (and optionally indent) text written in a given language. The distribution comes with a number of modes (see the <a href="../mode/"><code>mode/</code></a> directory), and it isn't hard to <a href="#modeapi">write new ones</a> for other languages. </section> <section id=usage> <h2>Basic Usage</h2> The easiest way to use CodeMirror is to simply load the script and style sheet found under <code>lib/</code> in the distribution, plus a mode script from one of the <code>mode/</code> directories. (See <a href="compress.html">the compression helper</a> for an easy way to combine scripts.) For example: <pre data-lang="text/html"><script src="lib/codemirror.js"></script> <link rel="stylesheet" href="lib/codemirror.css"> <script src="mode/javascript/javascript.js"></script></pre> (Alternatively, use a module loader. <a href="#modloader">More about that later.</a>) Having done this, an editor instance can be created like this: <pre data-lang="javascript">var myCodeMirror = CodeMirror(document.body);</pre> The editor will be appended to the document body, will start empty, and will use the mode that we loaded. To have more control over the new editor, a configuration object can be passed to <a href="#CodeMirror"><code>CodeMirror</code></a> as a second argument: <pre data-lang="javascript">var myCodeMirror = CodeMirror(document.body, { value: "function myScript(){return 100;}\n", mode: "javascript" });</pre> This will initialize the editor with a piece of code already in it, and explicitly tell it to use the JavaScript mode (which is useful when multiple modes are loaded). See <a href="#config">below</a> for a full discussion of the configuration options that CodeMirror accepts. In cases where you don't want to append the editor to an element, and need more control over the way it is inserted, the first argument to the <code>CodeMirror</code> function can also be a function that, when given a DOM element, inserts it into the document somewhere. This could be used to, for example, replace a textarea with a real editor: <pre data-lang="javascript">var myCodeMirror = CodeMirror(function(elt) { myTextArea.parentNode.replaceChild(elt, myTextArea); }, {value: myTextArea.value});</pre> However, for this use case, which is a common way to use CodeMirror, the library provides a much more powerful shortcut: <pre data-lang="javascript">var myCodeMirror = CodeMirror.fromTextArea(myTextArea);</pre> This will, among other things, ensure that the textarea's value is updated with the editor's contents when the form (if it is part of a form) is submitted. See the <a href="#fromTextArea">API reference</a> for a full description of this method. <h3 id=modloader>Module loaders</h3> The files in the CodeMirror distribution contain shims for loading them (and their dependencies) in AMD or CommonJS environments. If the variables <code>exports</code> and <code>module</code> exist and have type object, CommonJS-style require will be used. If not, but there is a function <code>define</code> with an <code>amd</code> property present, AMD-style (RequireJS) will be used. It is possible to use <a href="http://browserify.org/">Browserify</a> or similar tools to statically build modules using CodeMirror. Alternatively, use <a href="http://requirejs.org/">RequireJS</a> to dynamically load dependencies at runtime. Both of these approaches have the advantage that they don't use the global namespace and can, thus, do things like load multiple versions of CodeMirror alongside each other. Here's a simple example of using RequireJS to load CodeMirror: <pre data-lang="javascript">require([ "cm/lib/codemirror", "cm/mode/htmlmixed/htmlmixed" ], function(CodeMirror) { CodeMirror.fromTextArea(document.getElementById("code"), { lineNumbers: true, mode: "htmlmixed" }); });</pre> It will automatically load the modes that the mixed HTML mode depends on (XML, JavaScript, and CSS). Do not use RequireJS' <code>paths</code> option to configure the path to CodeMirror, since it will break loading submodules through relative paths. Use the <a href="http://requirejs.org/docs/api.html#packages"><code>packages</code></a> configuration option instead, as in: <pre data-lang=javascript>require.config({ packages: [{ name: "codemirror", location: "../path/to/codemirror", main: "lib/codemirror" }] });</pre> </section> <section id=config> <h2>Configuration</h2> Both the <a href="#CodeMirror"><code>CodeMirror</code></a> function and its <code>fromTextArea</code> method take as second (optional) argument an object containing configuration options. Any option not supplied like this will be taken from <a href="#defaults"><code>CodeMirror.defaults</code></a>, an object containing the default options. You can update this object to change the defaults on your page. Options are not checked in any way, so setting bogus option values is bound to lead to odd errors. These are the supported options: <dl> <dt id="option_value"><code>value: string|CodeMirror.Doc</code></dt> <dd>The starting value of the editor. Can be a string, or a <a href="#api_doc">document object</a>.</dd> <dt id="option_mode"><code>mode: string|object</code></dt> <dd>The mode to use. When not given, this will default to the first mode that was loaded. It may be a string, which either simply names the mode or is a <a href="http://en.wikipedia.org/wiki/MIME">MIME</a> type associated with the mode. Alternatively, it may be an object containing configuration options for the mode, with a <code>name</code> property that names the mode (for example <code>{name: "javascript", json: true}</code>). The demo pages for each mode contain information about what configuration parameters the mode supports. You can ask CodeMirror which modes and MIME types have been defined by inspecting the <code>CodeMirror.modes</code> and <code>CodeMirror.mimeModes</code> objects. The first maps mode names to their constructors, and the second maps MIME types to mode specs.</dd> <dt id="option_lineSeparator"><code>lineSeparator: string|null</code></dt> <dd>Explicitly set the line separator for the editor. By default (value <code>null</code>), the document will be split on CRLFs as well as lone CRs and LFs, and a single LF will be used as line separator in all output (such as <a href="#getValue"><code>getValue</code></a>). When a specific string is given, lines will only be split on that string, and output will, by default, use that same separator.</dd> <dt id="option_theme"><code>theme: string</code></dt> <dd>The theme to style the editor with. You must make sure the CSS file defining the corresponding <code>.cm-s-[name]</code> styles is loaded (see the <a href="../theme/"><code>theme</code></a> directory in the distribution). The default is <code>"default"</code>, for which colors are included in <code>codemirror.css</code>. It is possible to use multiple theming classes at once—for example <code>"foo bar"</code> will assign both the <code>cm-s-foo</code> and the <code>cm-s-bar</code> classes to the editor.</dd> <dt id="option_indentUnit"><code>indentUnit: integer</code></dt> <dd>How many spaces a block (whatever that means in the edited language) should be indented. The default is 2.</dd> <dt id="option_smartIndent"><code>smartIndent: boolean</code></dt> <dd>Whether to use the context-sensitive indentation that the mode provides (or just indent the same as the line before). Defaults to true.</dd> <dt id="option_tabSize"><code>tabSize: integer</code></dt> <dd>The width of a tab character. Defaults to 4.</dd> <dt id="option_indentWithTabs"><code>indentWithTabs: boolean</code></dt> <dd>Whether, when indenting, the first N*<code>tabSize</code> spaces should be replaced by N tabs. Default is false.</dd> <dt id="option_electricChars"><code>electricChars: boolean</code></dt> <dd>Configures whether the editor should re-indent the current line when a character is typed that might change its proper indentation (only works if the mode supports indentation). Default is true.</dd> <dt id="option_specialChars"><code>specialChars: RegExp</code></dt> <dd>A regular expression used to determine which characters should be replaced by a special <a href="#option_specialCharPlaceholder">placeholder</a>. Mostly useful for non-printing special characters. The default is <code>/[\u0000-\u001f\u007f\u00ad\u200b-\u200f\u2028\u2029\ufeff]/</code>.</dd> <dt id="option_specialCharPlaceholder"><code>specialCharPlaceholder: function(char) → Element</code></dt> <dd>A function that, given a special character identified by the <a href="#option_specialChars"><code>specialChars</code></a> option, produces a DOM node that is used to represent the character. By default, a red dot (•) is shown, with a title tooltip to indicate the character code.</dd> <dt id="option_rtlMoveVisually"><code>rtlMoveVisually: boolean</code></dt> <dd>Determines whether horizontal cursor movement through right-to-left (Arabic, Hebrew) text is visual (pressing the left arrow moves the cursor left) or logical (pressing the left arrow moves to the next lower index in the string, which is visually right in right-to-left text). The default is <code>false</code> on Windows, and <code>true</code> on other platforms.</dd> <dt id="option_keyMap"><code>keyMap: string</code></dt> <dd>Configures the key map to use. The default is <code>"default"</code>, which is the only key map defined in <code>codemirror.js</code> itself. Extra key maps are found in the <a href="../keymap/"><code>key map</code></a> directory. See the <a href="#keymaps">section on key maps</a> for more information.</dd> <dt id="option_extraKeys"><code>extraKeys: object</code></dt> <dd>Can be used to specify extra key bindings for the editor, alongside the ones defined by <a href="#option_keyMap"><code>keyMap</code></a>. Should be either null, or a valid <a href="#keymaps">key map</a> value.</dd> <dt id="option_lineWrapping"><code>lineWrapping: boolean</code></dt> <dd>Whether CodeMirror should scroll or wrap for long lines. Defaults to <code>false</code> (scroll).</dd> <dt id="option_lineNumbers"><code>lineNumbers: boolean</code></dt> <dd>Whether to show line numbers to the left of the editor.</dd> <dt id="option_firstLineNumber"><code>firstLineNumber: integer</code></dt> <dd>At which number to start counting lines. Default is 1.</dd> <dt id="option_lineNumberFormatter"><code>lineNumberFormatter: function(line: integer) → string</code></dt> <dd>A function used to format line numbers. The function is passed the line number, and should return a string that will be shown in the gutter.</dd> <dt id="option_gutters"><code>gutters: array<string></code></dt> <dd>Can be used to add extra gutters (beyond or instead of the line number gutter). Should be an array of CSS class names, each of which defines a <code>width</code> (and optionally a background), and which will be used to draw the background of the gutters. May include the <code>CodeMirror-linenumbers</code> class, in order to explicitly set the position of the line number gutter (it will default to be to the right of all other gutters). These class names are the keys passed to <a href="#setGutterMarker"><code>setGutterMarker</code></a>.</dd> <dt id="option_fixedGutter"><code>fixedGutter: boolean</code></dt> <dd>Determines whether the gutter scrolls along with the content horizontally (false) or whether it stays fixed during horizontal scrolling (true, the default).</dd> <dt id="option_scrollbarStyle"><code>scrollbarStyle: string</code></dt> <dd>Chooses a scrollbar implementation. The default is <code>"native"</code>, showing native scrollbars. The core library also provides the <code>"null"</code> style, which completely hides the scrollbars. <a href="#addon_simplescrollbars">Addons</a> can implement additional scrollbar models.</dd> <dt id="option_coverGutterNextToScrollbar"><code>coverGutterNextToScrollbar: boolean</code></dt> <dd>When <a href="#option_fixedGutter"><code>fixedGutter</code></a> is on, and there is a horizontal scrollbar, by default the gutter will be visible to the left of this scrollbar. If this option is set to true, it will be covered by an element with class <code>CodeMirror-gutter-filler</code>.</dd> <dt id="option_inputStyle"><code>inputStyle: string</code></dt> <dd>Selects the way CodeMirror handles input and focus. The core library defines the <code>"textarea"</code> and <code>"contenteditable"</code> input models. On mobile browsers, the default is <code>"contenteditable"</code>. On desktop browsers, the default is <code>"textarea"</code>. Support for IME and screen readers is better in the <code>"contenteditable"</code> model. The intention is to make it the default on modern desktop browsers in the future.</dd> <dt id="option_readOnly"><code>readOnly: boolean|string</code></dt> <dd>This disables editing of the editor content by the user. If the special value <code>"nocursor"</code> is given (instead of simply <code>true</code>), focusing of the editor is also disallowed.</dd> <dt id="option_showCursorWhenSelecting"><code>showCursorWhenSelecting: boolean</code></dt> <dd>Whether the cursor should be drawn when a selection is active. Defaults to false.</dd> <dt id="option_lineWiseCopyCut"><code>lineWiseCopyCut: boolean</code></dt> <dd>When enabled, which is the default, doing copy or cut when there is no selection will copy or cut the whole lines that have cursors on them.</dd> <dt id="option_undoDepth"><code>undoDepth: integer</code></dt> <dd>The maximum number of undo levels that the editor stores. Note that this includes selection change events. Defaults to 200.</dd> <dt id="option_historyEventDelay"><code>historyEventDelay: integer</code></dt> <dd>The period of inactivity (in milliseconds) that will cause a new history event to be started when typing or deleting. Defaults to 1250.</dd> <dt id="option_tabindex"><code>tabindex: integer</code></dt> <dd>The <a href="http://www.w3.org/TR/html401/interact/forms.html#adef-tabindex">tab index</a> to assign to the editor. If not given, no tab index will be assigned.</dd> <dt id="option_autofocus"><code>autofocus: boolean</code></dt> <dd>Can be used to make CodeMirror focus itself on initialization. Defaults to off. When <a href="#fromTextArea"><code>fromTextArea</code></a> is used, and no explicit value is given for this option, it will be set to true when either the source textarea is focused, or it has an <code>autofocus</code> attribute and no other element is focused.</dd> </dl> Below this a few more specialized, low-level options are listed. These are only useful in very specific situations, you might want to skip them the first time you read this manual. <dl> <dt id="option_dragDrop"><code>dragDrop: boolean</code></dt> <dd>Controls whether drag-and-drop is enabled. On by default.</dd> <dt id="option_allowDropFileTypes"><code>allowDropFileTypes: array<string></code></dt> <dd>When set (default is <code>null</code>) only files whose type is in the array can be dropped into the editor. The strings should be MIME types, and will be checked against the <a href="https://w3c.github.io/FileAPI/#dfn-type"><code>type</code></a> of the <code>File</code> object as reported by the browser.</dd> <dt id="option_cursorBlinkRate"><code>cursorBlinkRate: number</code></dt> <dd>Half-period in milliseconds used for cursor blinking. The default blink rate is 530ms. By setting this to zero, blinking can be disabled. A negative value hides the cursor entirely.</dd> <dt id="option_cursorScrollMargin"><code>cursorScrollMargin: number</code></dt> <dd>How much extra space to always keep above and below the cursor when approaching the top or bottom of the visible view in a scrollable document. Default is 0.</dd> <dt id="option_cursorHeight"><code>cursorHeight: number</code></dt> <dd>Determines the height of the cursor. Default is 1, meaning it spans the whole height of the line. For some fonts (and by some tastes) a smaller height (for example <code>0.85</code>), which causes the cursor to not reach all the way to the bottom of the line, looks better</dd> <dt id="option_resetSelectionOnContextMenu"><code>resetSelectionOnContextMenu: boolean</code></dt> <dd>Controls whether, when the context menu is opened with a click outside of the current selection, the cursor is moved to the point of the click. Defaults to <code>true</code>.</dd> <dt id="option_workTime"><code id="option_wordkDelay">workTime, workDelay: number</code></dt> <dd>Highlighting is done by a pseudo background-thread that will work for <code>workTime</code> milliseconds, and then use timeout to sleep for <code>workDelay</code> milliseconds. The defaults are 200 and 300, you can change these options to make the highlighting more or less aggressive.</dd> <dt id="option_pollInterval"><code>pollInterval: number</code></dt> <dd>Indicates how quickly CodeMirror should poll its input textarea for changes (when focused). Most input is captured by events, but some things, like IME input on some browsers, don't generate events that allow CodeMirror to properly detect it. Thus, it polls. Default is 100 milliseconds.</dd> <dt id="option_flattenSpans"><code>flattenSpans: boolean</code></dt> <dd>By default, CodeMirror will combine adjacent tokens into a single span if they have the same class. This will result in a simpler DOM tree, and thus perform better. With some kinds of styling (such as rounded corners), this will change the way the document looks. You can set this option to false to disable this behavior.</dd> <dt id="option_addModeClass"><code>addModeClass: boolean</code></dt> <dd>When enabled (off by default), an extra CSS class will be added to each token, indicating the (<a href="#innerMode">inner</a>) mode that produced it, prefixed with <code>"cm-m-"</code>. For example, tokens from the XML mode will get the <code>cm-m-xml</code> class.</dd> <dt id="option_maxHighlightLength"><code>maxHighlightLength: number</code></dt> <dd>When highlighting long lines, in order to stay responsive, the editor will give up and simply style the rest of the line as plain text when it reaches a certain position. The default is 10 000. You can set this to <code>Infinity</code> to turn off this behavior.</dd> <dt id="option_viewportMargin"><code>viewportMargin: integer</code></dt> <dd>Specifies the amount of lines that are rendered above and below the part of the document that's currently scrolled into view. This affects the amount of updates needed when scrolling, and the amount of work that such an update does. You should usually leave it at its default, 10. Can be set to <code>Infinity</code> to make sure the whole document is always rendered, and thus the browser's text search works on it. This will have bad effects on performance of big documents.</dd> </dl> </section> <section id=events> <h2>Events</h2> Various CodeMirror-related objects emit events, which allow client code to react to various situations. Handlers for such events can be registered with the <a href="#on"><code>on</code></a> and <a href="#off"><code>off</code></a> methods on the objects that the event fires on. To fire your own events, use <code>CodeMirror.signal(target, name, args...)</code>, where <code>target</code> is a non-DOM-node object. An editor instance fires the following events. The <code>instance</code> argument always refers to the editor itself. <dl> <dt id="event_change"><code>"change" (instance: CodeMirror, changeObj: object)</code></dt> <dd>Fires every time the content of the editor is changed. The <code>changeObj</code> is a <code>{from, to, text, removed, origin}</code> object containing information about the changes that occurred as second argument. <code>from</code> and <code>to</code> are the positions (in the pre-change coordinate system) where the change started and ended (for example, it might be <code>{ch:0, line:18}</code> if the position is at the beginning of line #19). <code>text</code> is an array of strings representing the text that replaced the changed range (split by line). <code>removed</code> is the text that used to be between <code>from</code> and <code>to</code>, which is overwritten by this change. This event is fired before the end of an <a href="#operation">operation</a>, before the DOM updates happen.</dd> <dt id="event_changes"><code>"changes" (instance: CodeMirror, changes: array<object>)</code></dt> <dd>Like the <a href="#event_change"><code>"change"</code></a> event, but batched per <a href="#operation">operation</a>, passing an array containing all the changes that happened in the operation. This event is fired after the operation finished, and display changes it makes will trigger a new operation.</dd> <dt id="event_beforeChange"><code>"beforeChange" (instance: CodeMirror, changeObj: object)</code></dt> <dd>This event is fired before a change is applied, and its handler may choose to modify or cancel the change. The <code>changeObj</code> object has <code>from</code>, <code>to</code>, and <code>text</code> properties, as with the <a href="#event_change"><code>"change"</code></a> event. It also has a <code>cancel()</code> method, which can be called to cancel the change, and, if the change isn't coming from an undo or redo event, an <code>update(from, to, text)</code> method, which may be used to modify the change. Undo or redo changes can't be modified, because they hold some metainformation for restoring old marked ranges that is only valid for that specific change. All three arguments to <code>update</code> are optional, and can be left off to leave the existing value for that field intact. Note: you may not do anything from a <code>"beforeChange"</code> handler that would cause changes to the document or its visualization. Doing so will, since this handler is called directly from the bowels of the CodeMirror implementation, probably cause the editor to become corrupted.</dd> <dt id="event_cursorActivity"><code>"cursorActivity" (instance: CodeMirror)</code></dt> <dd>Will be fired when the cursor or selection moves, or any change is made to the editor content.</dd> <dt id="event_keyHandled"><code>"keyHandled" (instance: CodeMirror, name: string, event: Event)</code></dt> <dd>Fired after a key is handled through a key map. <code>name</code> is the name of the handled key (for example <code>"Ctrl-X"</code> or <code>"'q'"</code>), and <code>event</code> is the DOM <code>keydown</code> or <code>keypress</code> event.</dd> <dt id="event_inputRead"><code>"inputRead" (instance: CodeMirror, changeObj: object)</code></dt> <dd>Fired whenever new input is read from the hidden textarea (typed or pasted by the user).</dd> <dt id="event_electricInput"><code>"electricInput" (instance: CodeMirror, line: integer)</code></dt> <dd>Fired if text input matched the mode's <a href="#option_electricChars">electric</a> patterns, and this caused the line's indentation to change.</dd> <dt id="event_beforeSelectionChange"><code>"beforeSelectionChange" (instance: CodeMirror, obj: {ranges, origin, update})</code></dt> <dd>This event is fired before the selection is moved. Its handler may inspect the set of selection ranges, present as an array of <code>{anchor, head}</code> objects in the <code>ranges</code> property of the <code>obj</code> argument, and optionally change them by calling the <code>update</code> method on this object, passing an array of ranges in the same format. The object also contains an <code>origin</code> property holding the origin string passed to the selection-changing method, if any. Handlers for this event have the same restriction as <a href="#event_beforeChange"><code>"beforeChange"</code></a> handlers — they should not do anything to directly update the state of the editor.</dd> <dt id="event_viewportChange"><code>"viewportChange" (instance: CodeMirror, from: number, to: number)</code></dt> <dd>Fires whenever the <a href="#getViewport">view port</a> of the editor changes (due to scrolling, editing, or any other factor). The <code>from</code> and <code>to</code> arguments give the new start and end of the viewport.</dd> <dt id="event_swapDoc"><code>"swapDoc" (instance: CodeMirror, oldDoc: Doc)</code></dt> <dd>This is signalled when the editor's document is replaced using the <a href="#swapDoc"><code>swapDoc</code></a> method.</dd> <dt id="event_gutterClick"><code>"gutterClick" (instance: CodeMirror, line: integer, gutter: string, clickEvent: Event)</code></dt> <dd>Fires when the editor gutter (the line-number area) is clicked. Will pass the editor instance as first argument, the (zero-based) number of the line that was clicked as second argument, the CSS class of the gutter that was clicked as third argument, and the raw <code>mousedown</code> event object as fourth argument.</dd> <dt id="event_gutterContextMenu"><code>"gutterContextMenu" (instance: CodeMirror, line: integer, gutter: string, contextMenu: Event: Event)</code></dt> <dd>Fires when the editor gutter (the line-number area) receives a <code>contextmenu</code> event. Will pass the editor instance as first argument, the (zero-based) number of the line that was clicked as second argument, the CSS class of the gutter that was clicked as third argument, and the raw <code>contextmenu</code> mouse event object as fourth argument. You can <code>preventDefault</code> the event, to signal that CodeMirror should do no further handling.</dd> <dt id="event_focus"><code>"focus" (instance: CodeMirror)</code></dt> <dd>Fires whenever the editor is focused.</dd> <dt id="event_blur"><code>"blur" (instance: CodeMirror)</code></dt> <dd>Fires whenever the editor is unfocused.</dd> <dt id="event_scroll"><code>"scroll" (instance: CodeMirror)</code></dt> <dd>Fires when the editor is scrolled.</dd> <dt id="event_scrollCursorIntoView"><code>"scrollCursorIntoView" (instance: CodeMirror, event: Event)</code></dt> <dd>Fires when the editor tries to scroll its cursor into view. Can be hooked into to take care of additional scrollable containers around the editor. When the event object has its <code>preventDefault</code> method called, CodeMirror will not itself try to scroll the window.</dd> <dt id="event_update"><code>"update" (instance: CodeMirror)</code></dt> <dd>Will be fired whenever CodeMirror updates its DOM display.</dd> <dt id="event_renderLine"><code>"renderLine" (instance: CodeMirror, line: LineHandle, element: Element)</code></dt> <dd>Fired whenever a line is (re-)rendered to the DOM. Fired right after the DOM element is built, before it is added to the document. The handler may mess with the style of the resulting element, or add event handlers, but should not try to change the state of the editor.</dd> <dt id="event_dom"><code>"mousedown", "dblclick", "touchstart", "contextmenu", "keydown", "keypress", "keyup", "cut", "copy", "paste", "dragstart", "dragenter", "dragover", "dragleave", "drop" (instance: CodeMirror, event: Event)</code></dt> <dd>Fired when CodeMirror is handling a DOM event of this type. You can <code>preventDefault</code> the event, or give it a truthy <code>codemirrorIgnore</code> property, to signal that CodeMirror should do no further handling.</dd> </dl> Document objects (instances of <a href="#Doc"><code>CodeMirror.Doc</code></a>) emit the following events: <dl> <dt id="event_doc_change"><code>"change" (doc: CodeMirror.Doc, changeObj: object)</code></dt> <dd>Fired whenever a change occurs to the document. <code>changeObj</code> has a similar type as the object passed to the editor's <a href="#event_change"><code>"change"</code></a> event.</dd> <dt id="event_doc_beforeChange"><code>"beforeChange" (doc: CodeMirror.Doc, change: object)</code></dt> <dd>See the <a href="#event_beforeChange">description of the same event</a> on editor instances.</dd> <dt id="event_doc_cursorActivity"><code>"cursorActivity" (doc: CodeMirror.Doc)</code></dt> <dd>Fired whenever the cursor or selection in this document changes.</dd> <dt id="event_doc_beforeSelectionChange"><code>"beforeSelectionChange" (doc: CodeMirror.Doc, selection: {head, anchor})</code></dt> <dd>Equivalent to the <a href="#event_beforeSelectionChange">event by the same name</a> as fired on editor instances.</dd> </dl> Line handles (as returned by, for example, <a href="#getLineHandle"><code>getLineHandle</code></a>) support these events: <dl> <dt id="event_delete"><code>"delete" ()</code></dt> <dd>Will be fired when the line object is deleted. A line object is associated with the start of the line. Mostly useful when you need to find out when your <a href="#setGutterMarker">gutter markers</a> on a given line are removed.</dd> <dt id="event_line_change"><code>"change" (line: LineHandle, changeObj: object)</code></dt> <dd>Fires when the line's text content is changed in any way (but the line is not deleted outright). The <code>change</code> object is similar to the one passed to <a href="#event_change">change event</a> on the editor object.</dd> </dl> Marked range handles (<code>CodeMirror.TextMarker</code>), as returned by <a href="#markText"><code>markText</code></a> and <a href="#setBookmark"><code>setBookmark</code></a>, emit the following events: <dl> <dt id="event_beforeCursorEnter"><code>"beforeCursorEnter" ()</code></dt> <dd>Fired when the cursor enters the marked range. From this event handler, the editor state may be inspected but not modified, with the exception that the range on which the event fires may be cleared.</dd> <dt id="event_clear"><code>"clear" (from: {line, ch}, to: {line, ch})</code></dt> <dd>Fired when the range is cleared, either through cursor movement in combination with <a href="#mark_clearOnEnter"><code>clearOnEnter</code></a> or through a call to its <code>clear()</code> method. Will only be fired once per handle. Note that deleting the range through text editing does not fire this event, because an undo action might bring the range back into existence. <code>from</code> and <code>to</code> give the part of the document that the range spanned when it was cleared.</dd> <dt id="event_hide"><code>"hide" ()</code></dt> <dd>Fired when the last part of the marker is removed from the document by editing operations.</dd> <dt id="event_unhide"><code>"unhide" ()</code></dt> <dd>Fired when, after the marker was removed by editing, a undo operation brought the marker back.</dd> </dl> Line widgets (<code>CodeMirror.LineWidget</code>), returned by <a href="#addLineWidget"><code>addLineWidget</code></a>, fire these events: <dl> <dt id="event_redraw"><code>"redraw" ()</code></dt> <dd>Fired whenever the editor re-adds the widget to the DOM. This will happen once right after the widget is added (if it is scrolled into view), and then again whenever it is scrolled out of view and back in again, or when changes to the editor options or the line the widget is on require the widget to be redrawn.</dd> </dl> </section> <section id=keymaps> <h2>Key Maps</h2> Key maps are ways to associate keys with functionality. A key map is an object mapping strings that identify the keys to functions that implement their functionality. The CodeMirror distributions comes with <a href="../demo/emacs.html">Emacs</a>, <a href="../demo/vim.html">Vim</a>, and <a href="../demo/sublime.html">Sublime Text</a>-style keymaps. Keys are identified either by name or by character. The <code>CodeMirror.keyNames</code> object defines names for common keys and associates them with their key codes. Examples of names defined here are <code>Enter</code>, <code>F5</code>, and <code>Q</code>. These can be prefixed with <code>Shift-</code>, <code>Cmd-</code>, <code>Ctrl-</code>, and <code>Alt-</code> to specify a modifier. So for example, <code>Shift-Ctrl-Space</code> would be a valid key identifier. Common example: map the Tab key to insert spaces instead of a tab character. <pre data-lang="javascript"> editor.setOption("extraKeys", { Tab: function(cm) { var spaces = Array(cm.getOption("indentUnit") + 1).join(" "); cm.replaceSelection(spaces); } });</pre> Alternatively, a character can be specified directly by surrounding it in single quotes, for example <code>'$'</code> or <code>'q'</code>. Due to limitations in the way browsers fire key events, these may not be prefixed with modifiers. Multi-stroke key bindings can be specified by separating the key names by spaces in the property name, for example <code>Ctrl-X Ctrl-V</code>. When a map contains multi-stoke bindings or keys with modifiers that are not specified in the default order (<code>Shift-Cmd-Ctrl-Alt</code>), you must call <code>CodeMirror.normalizeKeyMap</code> on it before it can be used. This function takes a keymap and modifies it to normalize modifier order and properly recognize multi-stroke bindings. It will return the keymap itself. The <code>CodeMirror.keyMap</code> object associates key maps with names. User code and key map definitions can assign extra properties to this object. Anywhere where a key map is expected, a string can be given, which will be looked up in this object. It also contains the <code>"default"</code> key map holding the default bindings. The values of properties in key maps can be either functions of a single argument (the CodeMirror instance), strings, or <code>false</code>. Strings refer to <a href="#commands">commands</a>, which are described below. If the property is set to <code>false</code>, CodeMirror leaves handling of the key up to the browser. A key handler function may return <code>CodeMirror.Pass</code> to indicate that it has decided not to handle the key, and other handlers (or the default behavior) should be given a turn. Keys mapped to command names that start with the characters <code>"go"</code> or to functions that have a truthy <code>motion</code> property (which should be used for cursor-movement actions) will be fired even when an extra <code>Shift</code> modifier is present (i.e. <code>"Up": "goLineUp"</code> matches both up and shift-up). This is used to easily implement shift-selection. Key maps can defer to each other by defining a <code>fallthrough</code> property. This indicates that when a key is not found in the map itself, one or more other maps should be searched. It can hold either a single key map or an array of key maps. When a key map needs to set something up when it becomes active, or tear something down when deactivated, it can contain <code>attach</code> and/or <code>detach</code> properties, which should hold functions that take the editor instance and the next or previous keymap. Note that this only works for the <a href="#option_keyMap">top-level keymap</a>, not for fallthrough maps or maps added with <a href="#option_extraKeys"><code>extraKeys</code></a> or <a href="#addKeyMap"><code>addKeyMap</code></a>. </section> <section id=commands> <h2>Commands</h2> Commands are parameter-less actions that can be performed on an editor. Their main use is for key bindings. Commands are defined by adding properties to the <code>CodeMirror.commands</code> object. A number of common commands are defined by the library itself, most of them used by the default key bindings. The value of a command property must be a function of one argument (an editor instance). Some of the commands below are referenced in the default key map, but not defined by the core library. These are intended to be defined by user code or addons. Commands can also be run with the <a href="#execCommand"><code>execCommand</code></a> method. <dl> <dt class=command id=command_selectAll><code>selectAll</code>Ctrl-A (PC), Cmd-A (Mac)</dt> <dd>Select the whole content of the editor.</dd> <dt class=command id=command_singleSelection><code>singleSelection</code>Esc</dt> <dd>When multiple selections are present, this deselects all but the primary selection.</dd> <dt class=command id=command_killLine><code>killLine</code>Ctrl-K (Mac)</dt> <dd>Emacs-style line killing. Deletes the part of the line after the cursor. If that consists only of whitespace, the newline at the end of the line is also deleted.</dd> <dt class=command id=command_deleteLine><code>deleteLine</code>Ctrl-D (PC), Cmd-D (Mac)</dt> <dd>Deletes the whole line under the cursor, including newline at the end.</dd> <dt class=command id=command_delLineLeft><code>delLineLeft</code></dt> <dd>Delete the part of the line before the cursor.</dd> <dt class=command id=command_delWrappedLineLeft><code>delWrappedLineLeft</code>Cmd-Backspace (Mac)</dt> <dd>Delete the part of the line from the left side of the visual line the cursor is on to the cursor.</dd> <dt class=command id=command_delWrappedLineRight><code>delWrappedLineRight</code>Cmd-Delete (Mac)</dt> <dd>Delete the part of the line from the cursor to the right side of the visual line the cursor is on.</dd> <dt class=command id=command_undo><code>undo</code>Ctrl-Z (PC), Cmd-Z (Mac)</dt> <dd>Undo the last change.</dd> <dt class=command id=command_redo><code>redo</code>Ctrl-Y (PC), Shift-Cmd-Z (Mac), Cmd-Y (Mac)</dt> <dd>Redo the last undone change.</dd> <dt class=command id=command_undoSelection><code>undoSelection</code>Ctrl-U (PC), Cmd-U (Mac)</dt> <dd>Undo the last change to the selection, or if there are no selection-only changes at the top of the history, undo the last change.</dd> <dt class=command id=command_redoSelection><code>redoSelection</code>Alt-U (PC), Shift-Cmd-U (Mac)</dt> <dd>Redo the last change to the selection, or the last text change if no selection changes remain.</dd> <dt class=command id=command_goDocStart><code>goDocStart</code>Ctrl-Home (PC), Cmd-Up (Mac), Cmd-Home (Mac)</dt> <dd>Move the cursor to the start of the document.</dd> <dt class=command id=command_goDocEnd><code>goDocEnd</code>Ctrl-End (PC), Cmd-End (Mac), Cmd-Down (Mac)</dt> <dd>Move the cursor to the end of the document.</dd> <dt class=command id=command_goLineStart><code>goLineStart</code>Alt-Left (PC), Ctrl-A (Mac)</dt> <dd>Move the cursor to the start of the line.</dd> <dt class=command id=command_goLineStartSmart><code>goLineStartSmart</code>Home</dt> <dd>Move to the start of the text on the line, or if we are already there, to the actual start of the line (including whitespace).</dd> <dt class=command id=command_goLineEnd><code>goLineEnd</code>Alt-Right (PC), Ctrl-E (Mac)</dt> <dd>Move the cursor to the end of the line.</dd> <dt class=command id=command_goLineRight><code>goLineRight</code>Cmd-Right (Mac)</dt> <dd>Move the cursor to the right side of the visual line it is on.</dd> <dt class=command id=command_goLineLeft><code>goLineLeft</code>Cmd-Left (Mac)</dt> <dd>Move the cursor to the left side of the visual line it is on. If this line is wrapped, that may not be the start of the line.</dd> <dt class=command id=command_goLineLeftSmart><code>goLineLeftSmart</code></dt> <dd>Move the cursor to the left side of the visual line it is on. If that takes it to the start of the line, behave like <a href="#command_goLineStartSmart"><code>goLineStartSmart</code></a>.</dd> <dt class=command id=command_goLineUp><code>goLineUp</code>Up, Ctrl-P (Mac)</dt> <dd>Move the cursor up one line.</dd> <dt class=command id=command_goLineDown><code>goLineDown</code>Down, Ctrl-N (Mac)</dt> <dd>Move down one line.</dd> <dt class=command id=command_goPageUp><code>goPageUp</code>PageUp, Shift-Ctrl-V (Mac)</dt> <dd>Move the cursor up one screen, and scroll up by the same distance.</dd> <dt class=command id=command_goPageDown><code>goPageDown</code>PageDown, Ctrl-V (Mac)</dt> <dd>Move the cursor down one screen, and scroll down by the same distance.</dd> <dt class=command id=command_goCharLeft><code>goCharLeft</code>Left, Ctrl-B (Mac)</dt> <dd>Move the cursor one character left, going to the