truncate-html

<h1 align="center">truncate-html</h1> <h5 align="center"> Truncate html string(even contains emoji chars) and keep tags in safe. You can custom ellipsis sign, ignore unwanted elements and truncate html by words. </h5> <div align="center"> <a href="https://github.com/oe/truncate-html/actions/workflows/main.yml"> <img src="https://github.com/oe/truncate-html/actions/workflows/main.yml/badge.svg" alt="Github Actions"> </a> <a href="#readme"> <img src="https://img.shields.io/badge/%3C%2F%3E-typescript-blue" alt="code with typescript"> </a> <a href="#readme"> <img src="https://badge.fury.io/js/truncate-html.svg" alt="npm version"> </a> <a href="https://www.npmjs.com/package/truncate-html"> <img src="https://img.shields.io/npm/dm/truncate-html.svg" alt="npm downloads"> </a> <a href="https://codecov.io/gh/oe/truncate-html"> <img src="https://codecov.io/gh/oe/truncate-html/branch/main/graph/badge.svg" alt="Coverage Status"> </a> </div> **Notice** This is a node module depends on [cheerio](https://github.com/cheeriojs/cheerio) _can only run on nodejs_. If you need a browser version, you may consider [truncate](https://github.com/pathable/truncate) or [nodejs-html-truncate](https://github.com/huang47/nodejs-html-truncate). ```javascript const truncate = require('truncate-html') truncate('<img src="xxx.jpg">Hello from earth!', 2, { byWords: true }) // => <img src="xxx.jpg">Hello from ... ``` ## Installation `npm install truncate-html` or `yarn add truncate-html` ## Try it online Click **<https://npm.runkit.com/truncate-html>** to try. ## API ```ts /** * custom node strategy, default to Cheerio<AnyNode> * * 'remove' to remove the node * * 'keep' to keep the node(and anything inside it) anyway, and won't be counted as there is no text content in it * * Cheerio<AnyNode> truncate the returned node * * undefined or any falsy value to truncate original node */ type ICustomNodeStrategy = (node: Cheerio<AnyNode>) => 'remove' | 'keep' | Cheerio<AnyNode> | undefined /** * truncate-html full options object */ interface IFullOptions { /** * remove all tags, default false */ stripTags: boolean /** * ellipsis sign, default '...' */ ellipsis: string /** * decode html entities(e.g. convert `&` to `&`) before counting length, default false */ decodeEntities: boolean /** * elements' selector you want ignore */ excludes: string | string[] /** * custom node strategy, default to Cheerio<AnyNode> * * 'remove' to remove the node * * 'keep' to keep the node(and anything inside it) anyway, and won't be counted as there is no text content in it * * Cheerio<AnyNode> truncate the returned node * * undefined or any falsy value to truncate original node */ customNodeStrategy: ICustomNodeStrategy /** * how many letters(words if `byWords` is true) you want reserve */ length: number /** * if true, length means how many words to reserve */ byWords: boolean /** * how to deal with when truncate in the middle of a word * 1. by default, just cut at that position. * 2. set it to true, with max exceed 10 letters can exceed to reserver the last word * 3. set it to a positive number decide how many letters can exceed to reserve the last word * 4. set it to negative number to remove the last word if cut in the middle. */ reserveLastWord: boolean | number /** * if reserveLastWord set to negative number, and there is only one word in the html string, when trimTheOnlyWord set to true, the extra letters will be sliced if word's length longer than `length`. * see issue #23 for more details */ trimTheOnlyWord: boolean /** * keep whitespaces, by default continuous paces will * be replaced with one space, set it true to keep them */ keepWhitespaces: boolean } /** * options interface for function */ type IOptions = Partial<IFullOptions> function truncate(html: string | CheerioAPI, length?: number | IOptions, truncateOptions?: IOptions): string // and truncate.setup to change default options truncate.setup(options: IOptions): void ``` ### Default options ```js { stripTags: false, ellipsis: '...', decodeEntities: false, excludes: '', byWords: false, reserveLastWord: false, trimTheOnlyWord: false, keepWhitespaces: false } ``` You can change default options by using `truncate.setup` e.g. ```ts truncate.setup({ stripTags: true, length: 10 }) truncate('<img src="xxx.jpg">Hello from earth!') // => Hello from ``` or use existing [cheerio instance](https://github.com/cheeriojs/cheerio#loading) ```ts import * as cheerio from 'cheerio' truncate.setup({ stripTags: true, length: 10 }) // truncate option `decodeEntities` will not work // you should config it in cheerio options by yourself const $ = cheerio.load('<img src="xxx.jpg">Hello from earth!', { /** set decodeEntities if you need it */ decodeEntities: true /* any cheerio instance options*/ }, false) // third parameter is for `isDocument` option, set to false to get rid of extra wrappers, see cheerio's doc for details truncate($) // => Hello from ``` ## Notice ### Typescript support This lib is written with typescript and has a type definition file along with it. ~~You may need to update your `tsconfig.json` by adding `"esModuleInterop": true` to the `compilerOptions` if you encounter some typing errors, see [#19](https://github.com/oe/truncate-html/issues/19).~~ ```ts import truncate, { type IOptions } from 'truncate-html' const html = '<img src="abc.png">italicboldThis is a string for test.' const options: IOptions = { length: 10, byWords: true } truncate(html, options) // => <img src="abc.png">italicbold... ``` ### custom node truncate strategy In complex html string, you may want to keep some special elements and truncate the others. You can use `customNodeStrategy` to achieve this: * return `'remove'` to remove the node * `keep` to keep the node(and anything inside it) anyway, and won't be counted as there is no text content in it * `Cheerio<AnyNode>` to truncate the returned node, or any falsy value to truncate the original node. ```ts import truncate, { type IOptions, type ICustomNodeStrategy } from 'truncate-html' // argument node is a cheerio instance const customNodeStrategy: ICustomNodeStrategy = node => { // remove img tag if (node.is('img')) { return 'remove' } // keep italic tag and its children if (node.is('i')) { return 'keep' } // truncate summary tag that inside details tag instead of details tag if (node.is('details')) { return node.find('summary') } } const html = '<div><img src="abc.png">italicbold<details><summary>Click me</summary>Some details</details>This is a string</div> for test.' const options: IOptions = { length: 10, customNodeStrategy } truncate(html, options) // => <div>italicbold<details><summary>Click me</summary>Some details</details>Th...</div> ``` ### About final string length If the html string content's length is shorter than `options.length`, then no ellipsis will be appended to the final html string. If longer, then the final string length will be `options.length` + `options.ellipsis`. And if you set `reserveLastWord` to true or none zero number or using `customNodeStrategy`, the final string will be various. ### About html comments All html comments `` will be removed ### About dealing with none alphabetic languages When dealing with none alphabetic languages, such as Chinese/Japanese/Korean, they don't separate words with whitespaces, so options `byWords` and `reserveLastWord` should only works well with alphabetic languages. And the only dependency of this project `cheerio` has an issue when dealing with none alphabetic languages, see [Known Issues](#known-issues) for details. ### Using existing cheerio instance If you want to use existing cheerio instance, truncate option `decodeEntities` will not work, you should set it in your own cheerio instance: ```js var html = '<img src="abc.png">This is a string for test.' const $ = cheerio.load(`${html}`, { decodeEntities: true /** other cheerio options */ }, false) // third parameter is for `isDocument` option, set to false to get rid of extra wrappers, see cheerio's doc for details truncate($, 10) ``` ## Examples ```javascript var truncate = require('truncate-html') // truncate html var html = '<img src="abc.png">This is a string for test.' truncate(html, 10) // returns: <img src="abc.png">This is a ... // truncate string with emojis var string = 'poo 💩💩💩💩💩' truncate(string, 6) // returns: poo 💩💩... // with options, remove all tags var html = '<img src="abc.png">This is a string for test.' truncate(html, 10, { stripTags: true }) // returns: This is a ... // with options, truncate by words. // if you try to truncate none alphabet language(like CJK) // it will not act as you wish var html = '<img src="abc.png">This is a string for test.' truncate(html, 3, { byWords: true }) // returns: <img src="abc.png">This is a ... // with options, keep whitespaces var html = ' <img src="abc.png">This is a string for test.' truncate(html, 10, { keepWhitespaces: true }) // returns: <img src="abc.png">This is a ... // combine length and options var html = '<img src="abc.png">This is a string for test.' truncate(html, { length: 10, stripTags: true }) // returns: This is a ... // custom ellipsis sign var html = '<img src="abc.png">This is a string for test.' truncate(html, { length: 10, ellipsis: '~' }) // returns: <img src="abc.png">This is a ~ // exclude some special elements(by selector), they will be removed before counting content's length var html = '<img src="abc.png">This is a string for test.' truncate(html, { length: 10, ellipsis: '~', excludes: 'img' }) // returns: This is a ~ // exclude more than one category elements var html = '<img src="abc.png">This is a string<div class="something-unwanted"> unwanted string inserted ( ´•̥̥̥ω•̥̥̥` ）</div> for test.' truncate(html, { length: 20, stripTags: true, ellipsis: '~', excludes: ['img', '.something-unwanted'] }) // returns: This is a string for~ // handing encoded characters var html = ' test for encoded string' truncate(html, { length: 20, decodeEntities: true }) // returns: test for encode... // when set decodeEntities false var html = ' test for encoded string' truncate(html, { length: 20, decodeEntities: false // this is the default value }) // returns:  test for <p... // and there may be a surprise by setting `decodeEntities` to true when handing CJK characters var html = ' test for 中文 string' truncate(html, { length: 20, decodeEntities: true }) // returns: test for 中文 str... // to fix this, see below for instructions // custom node strategy to keep some special elements var html = '<img src="abc.png">italicboldThis is a string for test.' truncate(html, { length: 10, customNodeStrategy: node => { if (node.is('img')) { return 'remove' } if (node.is('i')) { return 'keep' } } }) // returns: italicboldThis is a ... // custom node strategy to truncate summary instead of original node var html = '<div><details><summary>Click me</summary>Some details</details>other things</div>' truncate(html, { length: 10, customNodeStrategy: node => { if (node.is('details')) { return node.find('summary') } } }) // returns: <div><details><summary>Click me</summary>Some details</details>ot...</div> ``` for More usages, check [truncate.spec.ts](./test/truncate.spec.ts) ## Credits Thanks to: - [@calebeno](https://github.com/calebeno) es6 support and unit tests - [@aaditya-thakkar](https://github.com/aaditya-thakkar) emoji truncating support