Rich Text
This module contains helper functions to convert HTML or a DOM tree into a rich text value and back, and to modify the value with functions that are similar to String
methods, plus some additional ones for formatting.
Installation
Install the module
npm install @wordpress/rich-text
This package assumes that your code will run in an ES2015+ environment. If you're using an environment that has limited or no support for such language features and APIs, you should include the polyfill shipped in @wordpress/babel-preset-default
in your code.
Usage
The Rich Text package is designed to aid in the manipulation of plain text strings in order that they can represent complex formatting.
By using a RichTextValue
value object (referred to from here on as value
) it is possible to separate text from formatting, thereby affording the ability to easily search and manipulate rich formats.
Examples of rich formats include:
- bold, italic, superscript (etc)
- links
- unordered/ordered lists
The RichTextValue object
The value object is comprised of the following:
text
- the string of text to which rich formats are to be applied.formats
- a sparse array of the same length as text
that is filled with formats (e.g. core/link
, core/bold
etc.) at the positions where the text is formatted.start
- an index in the text
representing the start of the currently active selection.end
- an index in the text
representing the end of the currently active selection.
You should not attempt to create your own value
objects. Rather you should rely on the built in methods of the @wordpress/rich-text
package to build these for you.
It is important to understand how a value represents richly formatted text. Here is an example to illustrate.
If text
is formatted from position 2-5 in bold (core/bold
) and from position 2-8 with a link (core/link
), then you'll find:
- arrays within the sparse array at positions 2-5 that include the
core/bold
format - arrays within the sparse array at positions 2-8 that include the
core/link
format
Here's how that would look:
{
text: 'Hello world',
formats: [
[],
[],
[
{
type: 'core/bold',
},
{
type: 'core/link',
}
],
[
{
type: 'core/bold',
},
{
type: 'core/link',
}
],
[
{
type: 'core/bold',
},
{
type: 'core/link',
}
],
[
{
type: 'core/bold',
},
{
type: 'core/link',
}
],
[
{
type: 'core/link',
}
]
[
{
type: 'core/link',
}
],
[
{
type: 'core/link',
}
],
[],
[],
[],
]
}
Selections
Let's continue to consider the above example with the text Hello world
.
If, as a user, I make a selection of the word Hello
this would result in a value object with start
and end
as 0
and 5
respectively.
In general, this is useful for knowing which portion of the text is selected. However, we need to consider that selections may also be "collapsed".
Collapsed selections
A collapsed selection is one where start
and end
values are identical (e.g. start: 4, end: 4
). This happens when no characters are selected, but there is a caret present. This most often occurs when a user places the cursor/caret within a string of text but does not make a selection.
Given that the selection has no "range" (i.e. there is no difference between start
and end
indices), finding the currently selected portion of text from collapsed values can be challenging.
API
applyFormat
Apply a format object to a Rich Text value from the given startIndex
to the given endIndex
. Indices are retrieved from the selection if none are provided.
Parameters
- value
RichTextValue
: Value to modify. - format
RichTextFormat
: Format to apply. - startIndex
[number]
: Start index. - endIndex
[number]
: End index.
Returns
RichTextValue
: A new value with the format applied.
concat
Combine all Rich Text values into one. This is similar to String.prototype.concat
.
Parameters
- values
...RichTextValue
: Objects to combine.
Returns
RichTextValue
: A new value combining all given records.
create
Create a RichText value from an Element
tree (DOM), an HTML string or a plain text string, with optionally a Range
object to set the selection. If called without any input, an empty value will be created. The optional functions can be used to filter out content.
A value will have the following shape, which you are strongly encouraged not to modify without the use of helper functions:
{
text: string,
formats: Array,
replacements: Array,
?start: number,
?end: number,
}
As you can see, text and formatting are separated. text
holds the text, including any replacement characters for objects and lines. formats
, objects
and lines
are all sparse arrays of the same length as text
. It holds information about the formatting at the relevant text indices. Finally start
and end
state which text indices are selected. They are only provided if a Range
was given.
Parameters
- $1
[Object]
: Optional named arguments. - $1.element
[Element]
: Element to create value from. - $1.text
[string]
: Text to create value from. - $1.html
[string]
: HTML to create value from. - $1.range
[Range]
: Range to create value from. - $1.__unstableIsEditableTree
[boolean]
:
Returns
RichTextValue
: A rich text value.
getActiveFormat
Gets the format object by type at the start of the selection. This can be used to get e.g. the URL of a link format at the current selection, but also to check if a format is active at the selection. Returns undefined if there is no format at the selection.
Parameters
- value
RichTextValue
: Value to inspect. - formatType
string
: Format type to look for.
Returns
RichTextFormat|undefined
: Active format object of the specified type, or undefined.
getActiveFormats
Gets the all format objects at the start of the selection.
Parameters
- value
RichTextValue
: Value to inspect. - EMPTY_ACTIVE_FORMATS
Array
: Array to return if there are no active formats.
Returns
RichTextFormatList
: Active format objects.
getActiveObject
Gets the active object, if there is any.
Parameters
- value
RichTextValue
: Value to inspect.
Returns
RichTextFormat|void
: Active object, or undefined.
getTextContent
Get the textual content of a Rich Text value. This is similar to Element.textContent
.
Parameters
- value
RichTextValue
: Value to use.
Returns
string
: The text content.
insert
Insert a Rich Text value, an HTML string, or a plain text string, into a Rich Text value at the given startIndex
. Any content between startIndex
and endIndex
will be removed. Indices are retrieved from the selection if none are provided.
Parameters
- value
RichTextValue
: Value to modify. - valueToInsert
RichTextValue|string
: Value to insert. - startIndex
[number]
: Start index. - endIndex
[number]
: End index.
Returns
RichTextValue
: A new value with the value inserted.
insertObject
Insert a format as an object into a Rich Text value at the given startIndex
. Any content between startIndex
and endIndex
will be removed. Indices are retrieved from the selection if none are provided.
Parameters
- value
RichTextValue
: Value to modify. - formatToInsert
RichTextFormat
: Format to insert as object. - startIndex
[number]
: Start index. - endIndex
[number]
: End index.
Returns
RichTextValue
: A new value with the object inserted.
isCollapsed
Check if the selection of a Rich Text value is collapsed or not. Collapsed means that no characters are selected, but there is a caret present. If there is no selection, undefined
will be returned. This is similar to window.getSelection().isCollapsed()
.
Parameters
- props
RichTextValue
: The rich text value to check. - props.start
RichTextValue[ 'start' ]
: - props.end
RichTextValue[ 'end' ]
:
Returns
boolean | undefined
: True if the selection is collapsed, false if not, undefined if there is no selection.
isEmpty
Check if a Rich Text value is Empty, meaning it contains no text or any objects (such as images).
Parameters
- value
RichTextValue
: Value to use.
Returns
boolean
: True if the value is empty, false if not.
join
Combine an array of Rich Text values into one, optionally separated by separator
, which can be a Rich Text value, HTML string, or plain text string. This is similar to Array.prototype.join
.
Parameters
- values
Array<RichTextValue>
: An array of values to join. - separator
[string|RichTextValue]
: Separator string or value.
Returns
RichTextValue
: A new combined value.
registerFormatType
Registers a new format provided a unique name and an object defining its behavior.
Parameters
- name
string
: Format name. - settings
WPFormat
: Format settings.
Returns
WPFormat|undefined
: The format, if it has been successfully registered; otherwise undefined
.
remove
Remove content from a Rich Text value between the given startIndex
and endIndex
. Indices are retrieved from the selection if none are provided.
Parameters
- value
RichTextValue
: Value to modify. - startIndex
[number]
: Start index. - endIndex
[number]
: End index.
Returns
RichTextValue
: A new value with the content removed.
removeFormat
Remove any format object from a Rich Text value by type from the given startIndex
to the given endIndex
. Indices are retrieved from the selection if none are provided.
Parameters
- value
RichTextValue
: Value to modify. - formatType
string
: Format type to remove. - startIndex
[number]
: Start index. - endIndex
[number]
: End index.
Returns
RichTextValue
: A new value with the format applied.
replace
Search a Rich Text value and replace the match(es) with replacement
. This is similar to String.prototype.replace
.
Parameters
- value
RichTextValue
: The value to modify. - pattern
RegExp|string
: A RegExp object or literal. Can also be a string. It is treated as a verbatim string and is not interpreted as a regular expression. Only the first occurrence will be replaced. - replacement
Function|string
: The match or matches are replaced with the specified or the value returned by the specified function.
Returns
RichTextValue
: A new value with replacements applied.
RichTextData
The RichTextData class is used to instantiate a wrapper around rich text values, with methods that can be used to transform or manipulate the data.
- Create an emtpy instance:
new RichTextData()
. - Create one from an html string:
RichTextData.fromHTMLString( '<em>hello</em>' )
. - Create one from a wrapper HTMLElement:
RichTextData.fromHTMLElement( document.querySelector( 'p' ) )
. - Create one from plain text:
RichTextData.fromPlainText( '1\n2' )
. - Create one from a rich text value:
new RichTextData( { text: '...', formats: [ ... ] } )
.
RichTextValue
An object which represents a formatted string. See main @wordpress/rich-text
documentation for more information.
slice
Slice a Rich Text value from startIndex
to endIndex
. Indices are retrieved from the selection if none are provided. This is similar to String.prototype.slice
.
Parameters
- value
RichTextValue
: Value to modify. - startIndex
[number]
: Start index. - endIndex
[number]
: End index.
Returns
RichTextValue
: A new extracted value.
split
Split a Rich Text value in two at the given startIndex
and endIndex
, or split at the given separator. This is similar to String.prototype.split
. Indices are retrieved from the selection if none are provided.
Parameters
- value
RichTextValue
: - string
[number|string]
: Start index, or string at which to split.
Returns
Array<RichTextValue>|undefined
: An array of new values.
store
Store definition for the rich-text namespace.
Related
Type
toggleFormat
Toggles a format object to a Rich Text value at the current selection.
Parameters
- value
RichTextValue
: Value to modify. - format
RichTextFormat
: Format to apply or remove.
Returns
RichTextValue
: A new value with the format applied or removed.
toHTMLString
Create an HTML string from a Rich Text value.
Parameters
- $1
Object
: Named argements. - $1.value
RichTextValue
: Rich text value.
Returns
unregisterFormatType
Unregisters a format.
Parameters
- name
string
: Format name.
Returns
WPFormat|undefined
: The previous format value, if it has been successfully unregistered; otherwise undefined
.
useAnchor
This hook, to be used in a format type's Edit component, returns the active element that is formatted, or a virtual element for the selection range if no format is active. The returned value is meant to be used for positioning UI, e.g. by passing it to the Popover
component via the anchor
prop.
Parameters
- $1
Object
: Named parameters. - $1.editableContentElement
HTMLElement|null
: The element containing the editable content. - $1.settings
WPFormat=
: The format type's settings.
Returns
Element|VirtualAnchorElement|undefined|null
: The active element or selection range.
useAnchorRef
This hook, to be used in a format type's Edit component, returns the active element that is formatted, or the selection range if no format is active. The returned value is meant to be used for positioning UI, e.g. by passing it to the Popover
component.
Parameters
- $1
Object
: Named parameters. - $1.ref
RefObject<HTMLElement>
: React ref of the element containing the editable content. - $1.value
RichTextValue
: Value to check for selection. - $1.settings
WPFormat
: The format type's settings.
Returns
Element|Range
: The active element or selection range.
Contributing to this package
This is an individual package that's part of the Gutenberg project. The project is organized as a monorepo. It's made up of multiple self-contained software packages, each with a specific purpose. The packages in this monorepo are published to npm and used by WordPress as well as other software projects.
To find out more about contributing to this package or Gutenberg as a whole, please read the project's main contributor guide.