contentful-rich-text-html-parser
v1.6.0
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Convert any HTML to the Contentful Rich Text format
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Contentful Rich Text HTML Parser
Convert just about any HTML document to the Contentful Rich Text format!
This library aims to make it easy to convert any HTML to the Contentful Rich Text format. It will convert relevant HTML elements without any configuration and can be configured to support different styles of rich text formats.
Installation
npm install contentful-rich-text-html-parser
Usage
import { htmlStringToDocument } from "contentful-rich-text-html-parser";
const htmlString = `<p>Hello world!</p>`;
htmlStringToDocument(htmlString);
// {
// nodeType: 'document',
// content: [
// {
// nodeType: 'paragraph',
// content: [
// {
// nodeType: 'text',
// value: 'Hello world!',
// marks: [],
// },
// ],
// },
// ],
// };
HTML tag and rich text node support
The default configuration supports the following list of HTML tags which by default map to the corresponding rich text node type.
"h1" => BLOCKS.HEADING_1
"h2" => BLOCKS.HEADING_2
"h3" => BLOCKS.HEADING_3
"h4" => BLOCKS.HEADING_4
"h5" => BLOCKS.HEADING_5
"h6" => BLOCKS.HEADING_6
"hr" => BLOCKS.HR
"li" => BLOCKS.LIST_ITEM
"ol" => BLOCKS.OL_LIST
"p" => BLOCKS.PARAGRAPH
"blockquote" => BLOCKS.QUOTE
"table" => BLOCKS.TABLE
"td" => BLOCKS.TABLE_CELL
"th" => BLOCKS.TABLE_HEADER_CELL
"tr" => BLOCKS.TABLE_ROW
"ul" => BLOCKS.UL_LIST
"b" => MARKS.BOLD
"strong" => MARKS.BOLD
"pre" => MARKS.CODE
"i" => MARKS.ITALIC
"sub" => MARKS.SUBSCRIPT
"sup" => MARKS.SUPERSCRIPT
"u" => MARKS.UNDERLINE
"a" => INLINES.HYPERLINK
Adding support for other HTML elements or node types
This library can be configured to support custom HTML structures to fit your needs by using a custom options
-object.
import {
htmlStringToDocument,
Options,
TagConverter,
} from "contentful-rich-text-html-parser";
const myConverter: TagConverter = (node, next) => {
// My converter logic here...
};
const options: Options = {
convertTag: {
"any-html-tag-name-here": myConverter,
},
};
htmlStringToDocument(htmlString, options);
Writing custom converter functions
Custom converters can be written as functions taking two arguments:
- The
node
-object which represents the current HTML element. - The
next
-function which continues converting the child nodes of the HTML element.
The converter function should return a Contentful rich text node or a list of nodes.
import { BLOCKS } from "@contentful/rich-text-types";
const converter = (node, next) => ({
nodeType: BLOCKS.PARAGRAPH,
content: next(node),
data: {},
});
Adding marks can be done by passing them to the next
-function. Marks can be added as either a single mark or an array of marks.
import { BLOCKS } from "@contentful/rich-text-types";
const converter = (node, next) => ({
nodeType: BLOCKS.PARAGRAPH,
content: next(node, { type: "bold" }),
data: {},
});
Skipping an element can be done by returning the result of the next
-function. Ignoring an element AND its' children can be done by just returning an empty array. Skipping is the default behavior of any tag that is not supported.
const skippingConverter = (node, next) => next(node);
const ignoringConverter = (node, next) => [];
Example: Change all "div" elements to "p" elements
import { Block, BLOCKS } from "@contentful/rich-text-types";
import {
htmlStringToDocument,
Options,
TagConverter,
} from "contentful-rich-text-html-parser";
const divToParagraphConverter: TagConverter<Block> = (node, next) => {
return {
nodeType: BLOCKS.PARAGRAPH,
content: next(node),
data: {},
};
};
const options: Options = {
convertTag: {
div: divToParagraphConverter,
},
};
const htmlString = `<div>Text in a div!</div>`;
htmlStringToDocument(htmlString, options);
// {
// nodeType: 'document',
// content: [
// {
// nodeType: 'paragraph',
// content: [
// {
// nodeType: 'text',
// value: 'Text in a div!',
// marks: [],
// },
// ],
// },
// ],
// };
Example: Use a CSS class name to add a mark
import { Inline, Mark } from "@contentful/rich-text-types";
import {
htmlStringToDocument,
Options,
TagConverter,
} from "contentful-rich-text-html-parser";
const boldMark: Mark = {
type: "bold",
};
const spanWithMarksConverter: TagConverter<Inline> = (node, next) => {
const isBold = node.attrs.class === "bold";
// Ignore the "span" element while adding marks to all text element children.
return next(node, isBold ? boldMark : undefined);
};
const options: Options = {
convertTag: {
span: spanWithMarksConverter,
},
};
const htmlString = `<p><span class="bold">Bold text in a span!</span></p>`;
htmlStringToDocument(htmlString, options);
// {
// nodeType: 'document',
// content: [
// {
// nodeType: 'paragraph',
// content: [
// {
// nodeType: 'text',
// value: 'Bold text in a span!',
// marks: [{ type: 'bold' }],
// },
// ],
// },
// ],
// };
Assets, images, videos, other media, and files
By default, all img
, video
, source
, and other media elements are ignored by the parser.
It is however possible to add a convertTag
option to configure support for these elements yourself!
It is however important to note that you would have to find your own way of converting these images to valid assets that could be uploaded to Contentful if that is your goal"
Example: Custom "img" converter
import { Block, BLOCKS } from "@contentful/rich-text-types";
import {
htmlStringToDocument,
Options,
TagConverter,
} from "contentful-rich-text-html-parser";
const imgToEmbeddedAssetConverter: TagConverter<Block> = (node, next) => {
return {
nodeType: BLOCKS.EMBEDDED_ASSET,
content: next(node),
data: {
src: node.attrs.src,
},
};
};
const options: Options = {
convertTag: {
img: imgToEmbeddedAssetConverter,
},
};
const htmlString = `<img src="https://path-to-image" />`;
htmlStringToDocument(htmlString, options);
// {
// nodeType: 'document',
// content: [
// {
// nodeType: 'embedded-asset-block',
// content: [],
// data: { src: 'https://path-to-image' }
// },
// ],
// };
invalid Rich Text Documents
The Contentful Rich Text format requires the Document
adhere to a specific format.
The full ruleset can be found in the Contentful Documentation.
By default this library will convert any HTML node by node to create a rich text document. This means that the result can be an invalid document.
Uploading an invalid document to Contentful will result in an error. The @contentful/rich-text-types
package from Contentful includes a validateRichTextDocument
as of version 17.0.0
.
To mitigate invalid documents you have a few options:
- Use the built in
parserOptions
and/orpostProcessing
options. (Currently useful for removing whitespace, and fixing top level nodes). - Add a custom
TagConverter
ogTextConverter
that handles your case. (To handle cases like wrong child elements ofInline
nodes, list elements, or tables). - Change your HTML to a valid format before converting it.
Handling invalid top level nodes
Some elements can not be at the top level of a Document
. This includes Text
-nodes, Inline
-nodes, li
-elements, and any child element of table
(like a tr
or td
).
To handle cases where this appears this library includes a few utilities that process document after it has been created.
These options are:
options.postProcessing.handleTopLevelText: "preserve" | "remove" | "wrap-paragraph"
. Default:"preserve"
.options.postProcessing.handleTopLevelInlines: "preserve" | "remove" | "wrap-paragraph"
. Default:"preserve"
.
Examples of usage:
const htmlNodes = htmlStringToDocument(html, {
postProcessing: {
handleTopLevelText: "wrap-paragraph",
handleTopLevelInlines: "remove",
},
});
How it works:
"preserve"
: Keep top level nodes as they are, even if it results in an invalidDocument
."remove"
: Remove the node with all its child nodes from the document."wrap-paragraph"
: Wrap the node in a simpleparagraph
-node to make it valid.
Handling extra whitespace nodes
A formatted HTML string might include whitespace that will be parsed and added to the document output. This can result in unwanted text nodes or an invalid document.
Whitespace can be removed by using the handleWhitespaceNodes
option.
optons.parserOptions.handleWhitespaceNodes: "preserve" | "remove"
. Default:"preserve"
.
const htmlNodes = htmlStringToDocument(html, {
parserOptions: {
handleWhitespaceNodes: "preserve",
},
});
How it works:
"preserve"
: Keep all whitespace text nodes as they are in the original html string."remove"
: Remove any text node that consist purely of whitespace from the HTML node tree. Uses the following Regex/^\s*$/
.