README.md
1# react-markdown
2
3Renders Markdown as pure React components.
4
5[](https://www.npmjs.com/package/react-markdown)[](https://travis-ci.org/rexxars/react-markdown)
6
7Demo available at https://rexxars.github.io/react-markdown/
8
9---
10
11react-markdown is proudly sponsored by
12
13<a href="https://www.sanity.io/?utm_source=GitHub&utm_campaign=react-markdown" rel="nofollow" target="_blank">
14 <img src="https://www.sanity.io/static/images/logo_red.svg?v=2" width="300"><br />
15 Sanity: The Headless CMS Construction Kit
16</a>
17
18---
19
20## Installing
21
22```
23npm install --save react-markdown
24```
25
26## Basic usage
27
28```js
29const React = require('react')
30const ReactDOM = require('react-dom')
31const ReactMarkdown = require('react-markdown')
32
33const input = '# This is a header\n\nAnd this is a paragraph'
34
35ReactDOM.render(<ReactMarkdown source={input} />, document.getElementById('container'))
36```
37
38## Upgrading to 4.0
39
40Should be straightforward. You might need to alter you code slightly if you:
41
42- Are using `allowedTypes` (add `text` to the list)
43- Rely on there being a container `<div>` without a class name around your rendered markdown
44- Have implemented a custom `text` renderer
45
46See [CHANGELOG](CHANGELOG.md) for more details.
47
48## Notes
49
50If you don't need to render HTML, this component does not use `dangerouslySetInnerHTML` at all -
51this is a Good Thing™.
52
53## Options
54
55- `source` or `children` - _string_ The Markdown source to parse (**required**)
56- `className` - _string_ Class name of the container element. If none is passed, a container will not be rendered.
57- `escapeHtml` - _boolean_ Setting to `false` will cause HTML to be rendered (see notes below about proper HTML support). Be aware that setting this to `false` might cause security issues if the
58 input is user-generated. Use at your own risk. (default: `true`).
59- `skipHtml` - _boolean_ Setting to `true` will skip inlined and blocks of HTML (default: `false`).
60- `sourcePos` - _boolean_ Setting to `true` will add `data-sourcepos` attributes to all elements,
61 indicating where in the markdown source they were rendered from (default: `false`).
62- `rawSourcePos` - _boolean_ Setting to `true` will pass a `sourcePosition` property to all renderers with structured source position information (default: `false`).
63- `includeNodeIndex` - _boolean_ Setting to `true` will pass `index` and `parentChildCount` props to all renderers (default: `false`).
64- `allowedTypes` - _array_ Defines which types of nodes should be allowed (rendered). (default: all
65 types).
66- `disallowedTypes` - _array_ Defines which types of nodes should be disallowed (not rendered).
67 (default: none).
68- `unwrapDisallowed` - _boolean_ Setting to `true` will try to extract/unwrap the children of
69 disallowed nodes. For instance, if disallowing `Strong`, the default behaviour is to simply skip
70 the text within the strong altogether, while the behaviour some might want is to simply have the
71 text returned without the strong wrapping it. (default: `false`)
72- `allowNode` - _function_ Function execute if in order to determine if the node should be allowed.
73 Ran prior to checking `allowedTypes`/`disallowedTypes`. Returning a truthy value will allow the
74 node to be included. Note that if this function returns `true` and the type is not in
75 `allowedTypes` (or specified as a `disallowedType`), it won't be included. The function will
76 receive three arguments argument (`node`, `index`, `parent`), where `node` contains different
77 properties depending on the node type.
78- `linkTarget` - _function|string_ Sets the default target attribute for links. If a function is
79 provided, it will be called with `url`, `text`, and `title` and should return a string
80 (e.g. `_blank` for a new tab). Default is `undefined` (no target attribute).
81- `transformLinkUri` - _function|null_ Function that gets called for each encountered link with a
82 single argument - `uri`. The returned value is used in place of the original. The default link URI
83 transformer acts as an XSS-filter, neutralizing things like `javascript:`, `vbscript:` and `file:`
84 protocols. If you specify a custom function, this default filter won't be called, but you can
85 access it as `require('react-markdown').uriTransformer`. If you want to disable the default
86 transformer, pass `null` to this option.
87- `transformImageUri` - _function|null_ Function that gets called for each encountered image with a
88 single argument - `uri`. The returned value is used in place of the original.
89- `renderers` - _object_ An object where the keys represent the node type and the value is a React
90 component. The object is merged with the default renderers. The props passed to the component
91 varies based on the type of node.
92- `plugins` - _array_ An array of unified/remark parser plugins. If you need to pass options to the plugin, pass an array with two elements, the first being the plugin and the second being the options - for instance: `{plugins: [[require('remark-shortcodes'), {your: 'options'}]]`. (default: `[]`) Note that [not all plugins can be used](https://github.com/rexxars/react-markdown/issues/188#issuecomment-404710893).
93- `parserOptions` - _object_ An object containing options to pass to [remark-parse](https://github.com/remarkjs/remark/tree/master/packages/remark-parse).
94
95## Parsing HTML
96
97If you are in a trusted environment and want to parse and render HTML, you will want to use the `html-parser` plugin. For a default configuration, import `react-markdown/with-html` instead of the default:
98
99```js
100const ReactMarkdown = require('react-markdown/with-html')
101
102const markdown = `
103This block of Markdown contains <a href="https://en.wikipedia.org/wiki/HTML">HTML</a>, and will require the <code>html-parser</code> AST plugin to be loaded, in addition to setting the <code class="prop">escapeHtml</code> property to false.
104`
105
106<ReactMarkdown
107 source={markdown}
108 escapeHtml={false}
109/>
110```
111
112If you want to specify options for the HTML parsing step, you can instead import the HTML parser plugin directly:
113
114```js
115const ReactMarkdown = require('react-markdown')
116const htmlParser = require('react-markdown/plugins/html-parser')
117
118// See https://github.com/aknuds1/html-to-react#with-custom-processing-instructions
119// for more info on the processing instructions
120const parseHtml = htmlParser({
121 isValidNode: node => node.type !== 'script',
122 processingInstructions: [/* ... */]
123})
124
125<ReactMarkdown
126 source={markdown}
127 escapeHtml={false}
128 astPlugins={[parseHtml]}
129/>
130```
131
132## Node types
133
134The node types available are the following, and applies to both `renderers` and
135`allowedTypes`/`disallowedTypes`:
136
137- `root` - Root container element that contains the rendered markdown
138- `text` - Text rendered inside of other elements, such as paragraphs
139- `break` - Hard-break (`<br>`)
140- `paragraph` - Paragraph (`<p>`)
141- `emphasis` - Emphasis (`<em>`)
142- `strong` - Strong/bold (`<strong>`)
143- `thematicBreak` - Horizontal rule / thematic break (`<hr>`)
144- `blockquote` - Block quote (`<blockquote>`)
145- `delete` - Deleted/strike-through (`<del>`)
146- `link` - Link (`<a>`)
147- `image` - Image (`<img>`)
148- `linkReference` - Link (through a reference) (`<a>`)
149- `imageReference` - Image (through a reference) (`<img>`)
150- `table` - Table (`<table>`)
151- `tableHead` - Table head (`<thead>`)
152- `tableBody` - Table body (`<tbody>`)
153- `tableRow` - Table row (`<tr>`)
154- `tableCell` - Table cell (`<td>`/`<th>`)
155- `list` - List (`<ul>`/`<ol>`)
156- `listItem` - List item (`<li>`)
157- `definition` - Definition (not rendered by default)
158- `heading` - Heading (`<h1>`-`<h6>`)
159- `inlineCode` - Inline code (`<code>`)
160- `code` - Block of code (`<pre><code>`)
161- `html` - HTML node (Best-effort rendering)
162- `virtualHtml` - When not using the HTML parser plugin, a cheap and dirty approach to supporting simple HTML elements without a complete parser.
163- `parsedHtml` - When using the HTML parser plugin, HTML parsed to a React element.
164
165Note: Disallowing a node will also prevent the rendering of any children of that node, unless the
166`unwrapDisallowed` option is set to `true`. E.g., disallowing a paragraph will not render its
167children text nodes.
168
169## Developing
170
171```bash
172git clone git@github.com:rexxars/react-markdown.git
173cd react-markdown
174npm install
175npm test
176```
177
178## License
179
180MIT © [Espen Hovlandsdal](https://espen.codes/)
181
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