Squire is an HTML5 rich text editor, which provides powerful cross-browser normalisation, whilst being supremely lightweight and flexible. It is built for the present and the future, and as such does not support truly ancient browsers. It should work fine back to around Opera 12, Firefox 3.5, Safari 5, Chrome 9 and IE9.
Unlike other HTML5 rich text editors, Squire was written as a component for writing documents (emails, essays, etc.), not doing wysiwyg websites. If you are looking for support for inserting form controls or flash components or the like, you'll need to look elsewhere. However for many purposes, Squire may be just what you need, providing the power without the bloat. The key features are:
* No UI for a toolbar is supplied, allowing you to integrate seamlessly with the rest of your application and lose the bloat of having two UI toolkits loaded. Instead, you get a component you can insert in place of a `<textarea>` and manipulate programatically.
Squire provides an engine that handles the heavy work for you, making it easy to add extra features. With the `changeFormat` method you can easily add or remove any inline formatting you wish. And the `modifyBlocks` method can be used to make complicated block-level changes in a relatively easy manner.
If you need more commands than in the simple API, I suggest you check out the source code (it's not very long), and see how a lot of the other API methods are implemented in terms of these two methods.
The general philosophy of Squire is to allow the browser to do as much as it can (which unfortunately is not very much), but take control anywhere it deviates from what is required, or there are significant cross-browser differences. As such, the [`document.execCommand`](https://developer.mozilla.org/en-US/docs/Web/API/Document/execCommand) method is not used at all; instead all formatting is done via custom functions, and certain keys, such as 'enter' and 'backspace' are handled by the editor.
If you load the library into a top-level document (rather than an iframe), or load it in an iframe without the `data-squireinit="true"` attribute on its `<html>` element, it will not turn the page into an editable document, but will instead add a constructor named `Squire` to the global scope.
Call `new Squire( document )`, with the `document` from an iframe to instantiate multiple rich text areas on the same page efficiently. Note, for compatibility with all browsers (particularly Firefox), you MUST wait for the iframe's `onload` event to fire before instantiating Squire.
By default, the editor will use a `<div>` for blank lines, as most users have been conditioned by Microsoft Word to expect <kbd>Enter</kbd> to act like pressing <kbd>return</kbd> on a typewriter. If you would like to use `<p>` tags (or anything else) for the default block type instead, you can pass a config object as the second parameter to the squire constructor. You can also
pass a set of attributes to apply to each default block:
If you are adding a UI to Squire, you'll probably want to show a button in different states depending on whether a particular style is active in the current selection or not. For example, a "Bold" button would be in a depressed state if the text under the cursor is already bold.
The efficient way to determine the state for most buttons is to monitor the "pathChange" event in the editor, and determine the state from the new path. If the selection goes across nodes, you will need to call the `hasFormat` method for each of your buttons to determine whether the styles are active. See the `getPath` and `hasFormat` documentation for more information.
Attach an event listener to the editor. The handler can be either a function or an object with a `handleEvent` method. This function or method will be called whenever the event fires, with an event object as the sole argument. The following events may be observed:
* **pathChange**: The path (see getPath documentation) to the cursor has changed. The new path is available as the `path` property on the event object.
* **undoStateChange**: The availability of undo and/or redo has changed. The event object has two boolean properties, `canUndo` and `canRedo` to let you know the new state.
* **willPaste**: The user is pasting content into the document. The content that will be inserted is available as the `fragment` property on the event object. You can modify this fragment in your event handler to change what will be pasted. You can also call the `preventDefault` on the event object to cancel the paste operation.
Adds or removes a keyboard shortcut. You can use this to override the default keyboard shortcuts (e.g. Ctrl-B for bold –see the bottom of KeyHandlers.js for the list).
This method takes two arguments:
* **key**: The key to handle, including any modifiers in alphabetical order. e.g. `"alt-ctrl-meta-shift-enter"`
* **fn**: The function to be called when this key is pressed, or `null` if removing a key handler. The function will be passed three arguments when called:
* **self**: A reference to the Squire instance.
* **event**: The key event object.
* **range**: A Range object representing the current selection.
Returns the HTML value of the editor in its current state. This value is equivalent to the contents of the `<body>` tag and does not include any surrounding boilerplate.
Inserts an HTML fragment at the current cursor location, or replaces the selection if selected. The value supplied should not contain `<body>` tags or anything outside of that.
Returns the path through the DOM tree from the `<body>` element to the current current cursor position. This is a string consisting of the tag, id and class names in CSS format. For example `BODY>BLOCKQUOTE>DIV#id>STRONG>SPAN.font>EM`. If a selection has been made, so different parts of the selection may have different paths, the value will be `(selection)`. The path is useful for efficiently determining the current formatting for bold, italic, underline etc, and thus determining button state. If a selection has been made, you can has the `hasFormat` method instead to get the current state for the properties you care about.
Returns an object containing the font-family and font-size information for the element the cursor is in, if any was set. It uses style declarations to detect this, and so will not detect FONT tags. If a selection across multiple elements has been made, it will return an empty object.
Makes the currently selected text a link. If no text is selected, the URL or email will be inserted as text at the current cursor point and made into a link.
* **attributes**: (optional) An object containing other attributes to set on the `<a>` node. e.g. `{ target: '_blank' }`. Any `href` attribute will be overwritten by the url given as the first argument.
* **size**: A size to set. Any CSS [length value](https://developer.mozilla.org/en-US/docs/Web/CSS/length) or [absolute-size value](https://developer.mozilla.org/en-US/docs/Web/CSS/CSS_values_syntax#syntax-absolute-size) is accepted, e.g. '13px', or 'small'.
* **colour**: The colour to set. Any [CSS colour value](https://developer.mozilla.org/en-US/docs/Web/CSS/color_value) is accepted, e.g. '#f00', or 'hsl(0,0,0)'.
* **colour**: The colour to set. Any [CSS colour value](https://developer.mozilla.org/en-US/docs/Web/CSS/color_value) is accepted, e.g. '#f00', or 'hsl(0,0,0)'.
* **fn** The function to execute on each block node at least partially contained in the current selection. The function will be called with the block node as the only argument.
* **mutates** A boolean indicating whether your function may modify anything in the document in any way.
Extracts a portion of the DOM tree (up to the block boundaries of the current selection), modifies it and then reinserts it and merges the edges. See the code for examples if you're interested in using this function.
* **modify** The function to apply to the extracted DOM tree; gets a document fragment as a sole argument. `this` is bound to the Squire instance. Should return the node or fragment to be reinserted in the DOM.
