Trix Scientific
A modified version of Basecamp's Trix editor for use in scientific applications.
Modifications include:
- Superscript tags
- Subscript tags
- Text underlining
- Common notation symbols
- Registration/Copyright/Trademark symbols
- Greek Alpha and Beta symbols
- Removal of quote and code blocks
Getting Started
Include the bundled trix.css
and trix.js
files in the <head>
of your page.
…
trix.css
includes default styles for the Trix toolbar, editor, and attachments. Skip this file if you prefer to define these styles yourself.
To use your own polyfills, or to target only browsers that support all of the required standards, include trix-core.js
instead.
Creating an Editor
Place an empty <trix-editor></trix-editor>
tag on the page. Trix will automatically insert a separate <trix-toolbar>
before the editor.
Like an HTML <textarea>
, <trix-editor>
accepts autofocus
and placeholder
attributes. Unlike a <textarea>
, <trix-editor>
automatically expands vertically to fit its contents.
Integrating With Forms
To submit the contents of a <trix-editor>
with a form, first define a hidden input field in the form and assign it an id
. Then reference that id
in the editor’s input
attribute.
Trix will automatically update the value of the hidden input field with each change to the editor.
Populating With Stored Content
To populate a <trix-editor>
with stored content, include that content in the associated input element’s value
attribute.
Always use an associated input element to safely populate an editor. Trix won’t load any HTML content inside a <trix-editor>…</trix-editor>
tag.
Styling Formatted Content
To ensure what you see when you edit is what you see when you save, use a CSS class name to scope styles for Trix formatted content. Apply this class name to your <trix-editor>
element, and to a containing element when you render stored Trix content for display in your application.
Stored content here
The default trix.css
file includes styles for basic formatted content—including bulleted and numbered lists, code blocks, and block quotes—under the class name trix-content
. We encourage you to use these styles as a starting point by copying them into your application’s CSS with a different class name.
Storing Attached Files
Trix automatically accepts files dragged or pasted into an editor and inserts them as attachments in the document. Each attachment is considered pending until you store it remotely and provide Trix with a permanent URL.
To store attachments, listen for the trix-attachment-add
event. Upload the attached files with XMLHttpRequest yourself and set the attachment’s URL attribute upon completion. See the attachment example for detailed information.
If you don’t want to accept dropped or pasted files, call preventDefault()
on the trix-file-accept
event, which Trix dispatches just before the trix-attachment-add
event.
Editing Text Programmatically
You can manipulate a Trix editor programmatically through the Trix.Editor
interface, available on each <trix-editor>
element through its editor
property.
var element = documentelementeditor // is a Trix.Editor instance
Understanding the Document Model
The formatted content of a Trix editor is known as a document, and is represented as an instance of the Trix.Document
class. To get the editor’s current document, use the editor.getDocument
method.
elementeditor // is a Trix.Document instance
You can convert a document to an unformatted JavaScript string with the document.toString
method.
var document = elementeditordocument // is a JavaScript string
Immutability and Equality
Documents are immutable values. Each change you make in an editor replaces the previous document with a new document. Capturing a snapshot of the editor’s content is as simple as keeping a reference to its document, since that document will never change over time. (This is how Trix implements undo.)
To compare two documents for equality, use the document.isEqualTo
method.
var document = elementeditordocument // true
Getting and Setting the Selection
Trix documents are structured as sequences of individually addressable characters. The index of one character in a document is called a position, and a start and end position together make up a range.
To get the editor’s current selection, use the editor.getSelectedRange
method, which returns a two-element array containing the start and end positions.
elementeditor // [0, 0]
You can set the editor’s current selection by passing a range array to the editor.setSelectedRange
method.
// Select the first character in the documentelementeditor
Collapsed Selections
When the start and end positions of a range are equal, the range is said to be collapsed. In the editor, a collapsed selection appears as a blinking cursor rather than a highlighted span of text.
For convenience, the following calls to setSelectedRange
are equivalent when working with collapsed selections:
elementeditorelementeditorelementeditor
Directional Movement
To programmatically move the cursor or selection through the document, call the editor.moveCursorInDirection
or editor.expandSelectionInDirection
methods with a direction argument. The direction can be either "forward"
or "backward"
.
// Move the cursor backward one characterelementeditor // Expand the end of the selection forward by one characterelementeditor
Converting Positions to Pixel Offsets
Sometimes you need to know the x and y coordinates of a character at a given position in the editor. For example, you might want to absolutely position a pop-up menu element below the editor’s cursor.
Call the editor.getClientRectAtPosition
method with a position argument to get a DOMRect
instance representing the left and top offsets, width, and height of the character at the given position.
var rect = elementeditorrectleft recttop // [17, 49]
Inserting and Deleting Text
The editor interface provides methods for inserting, replacing, and deleting text at the current selection.
To insert or replace text, begin by setting the selected range, then call one of the insertion methods below. Trix will first remove any selected text, then insert the new text at the start position of the selected range.
Inserting Plain Text
To insert unformatted text into the document, call the editor.insertString
method.
// Insert “Hello” at the beginning of the documentelementeditorelementeditor
Inserting HTML
To insert HTML into the document, call the editor.insertHTML
method. Trix will first convert the HTML into its internal document model. During this conversion, any formatting that cannot be represented in a Trix document will be lost.
// Insert a bold “Hello” at the beginning of the documentelementeditorelementeditor
Inserting a File
To insert a DOM File
object into the document, call the editor.insertFile
method. Trix will insert a pending attachment for the file as if you had dragged and dropped it onto the editor.
// Insert the selected file from the first file input elementvar file = documentfileelementeditor
Inserting a Line Break
To insert a line break, call the editor.insertLineBreak
method, which is functionally equivalent to pressing the return key.
// Insert “Hello\n”elementeditorelementeditor
Deleting Text
If the current selection is collapsed, you can simulate deleting text before or after the cursor with the editor.deleteInDirection
method.
// “Backspace” the first character in the documentelementeditorelementeditor // Delete the second character in the documentelementeditorelementeditor
To delete a range of text, first set the selected range, then call editor.deleteInDirection
with either direction as the argument.
// Delete the first five characterselementeditorelementeditor
Working With Attributes and Nesting
Trix represents formatting as sets of attributes applied across ranges of a document.
By default, Trix supports the inline attributes bold
, italic
, href
, and strike
, and the block-level attributes heading1
, quote
, code
, bullet
, and number
.
Applying Formatting
To apply formatting to the current selection, use the editor.activateAttribute
method.
elementeditorelementeditorelementeditor
To set the href
attribute, pass a URL as the second argument to editor.activateAttribute
.
elementeditorelementeditorelementeditor
Removing Formatting
Use the editor.deactivateAttribute
method to remove formatting from a selection.
elementeditorelementeditor
Formatting With a Collapsed Selection
If you activate or deactivate attributes when the selection is collapsed, your formatting changes will apply to the text inserted by any subsequent calls to editor.insertString
.
elementeditorelementeditor
Adjusting the Nesting Level
To adjust the nesting level of quotes, bulleted lists, or numbered lists, call the editor.increaseNestingLevel
and editor.decreaseNestingLevel
methods.
elementeditorelementeditorelementeditor
Using Undo and Redo
Trix editors support unlimited undo and redo. Successive typing and formatting changes are consolidated together at five-second intervals; all other input changes are recorded individually in undo history.
Call the editor.undo
and editor.redo
methods to perform an undo or redo operation.
elementeditorelementeditor
Changes you make through the editor interface will not automatically record undo entries. You can save your own undo entries by calling the editor.recordUndoEntry
method with a description argument.
elementeditorelementeditor
Loading and Saving Editor State
Serialize an editor’s state with JSON.stringify
and restore saved state with the editor.loadJSON
method. The serialized state includes the document and current selection, but does not include undo history.
// Save editor state to local storagelocalStorage"editorState" = JSON // Restore editor state from local storageelementeditor
Observing Editor Changes
The <trix-editor>
element emits several events which you can use to observe and respond to changes in editor state.
-
trix-initialize
fires when the<trix-editor>
element is attached to the DOM and itseditor
object is ready for use. -
trix-change
fires whenever the editor’s contents have changed. -
trix-selection-change
fires any time the selected range changes in the editor. -
trix-focus
andtrix-blur
fire when the editor gains or loses focus, respectively. -
trix-file-accept
fires when a file is dropped or inserted into the editor. You can access the DOMFile
object through thefile
property on the event. CallpreventDefault
on the event to prevent attaching the file to the document. -
trix-attachment-add
fires after an attachment is added to the document. You can access the Trix attachment object through theattachment
property on the event. If theattachment
object has afile
property, you should store this file remotely and set the attachment’s URL attribute. See the attachment example for detailed information. -
trix-attachment-remove
fires when an attachment is removed from the document. You can access the Trix attachment object through theattachment
property on the event. You may wish to use this event to clean up remotely stored files.
Contributing
Bug reports and pull requests are welcome on GitHub at https://github.com/DRBragg/trix-scientific. This project is intended to be a safe, welcoming space for collaboration, and contributors are expected to adhere to the Contributor Covenant code of conduct.
License
The gem is available as open source under the terms of the MIT License.
Code of Conduct
Everyone interacting in the Trix Scientific project’s codebases, issue trackers, chat rooms and mailing lists is expected to follow the code of conduct.
Credits
This project is a direct modification of Basecamp's Trix WYSIWYG editor. Without their time and effort this wouldn't exist.
A huge thanks to my employer Cello Health Communications for not only being super supportive of open source projects and giving me the time and support to work on this project, but also for constantly pushing me to be better and continue to learn and grow.