115 lines
2.6 KiB
Markdown
115 lines
2.6 KiB
Markdown
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# srcset
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> Parse and stringify the HTML `<img>` [srcset](https://www.smashingmagazine.com/2013/08/webkit-implements-srcset-and-why-its-a-good-thing/) attribute.
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Can be useful if you're creating a build-tool.
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## Install
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```
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$ npm install srcset
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```
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## Usage
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How an image with `srcset` might look like:
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```html
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<img
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alt="The Breakfast Combo"
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src="banner.jpg"
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srcset="banner-HD.jpg 2x, banner-phone.jpg 100w"
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>
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```
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Then have some fun with it:
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```js
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const srcset = require('srcset');
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const parsed = srcset.parse('banner-HD.jpg 2x, banner-phone.jpg 100w');
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console.log(parsed);
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/*
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[
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{
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url: 'banner-HD.jpg',
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density: 2
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},
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{
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url: 'banner-phone.jpg',
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width: 100
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}
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]
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*/
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parsed.push({
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url: 'banner-super-HD.jpg',
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density: 3
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});
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const stringified = srcset.stringify(parsed);
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console.log(stringified);
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/*
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banner-HD.jpg 2x, banner-phone.jpg 100w, banner-super-HD.jpg 3x
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*/
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```
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## API
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### .parse(string, options?)
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Parse the HTML `<img>` [srcset](http://mobile.smashingmagazine.com/2013/08/21/webkit-implements-srcset-and-why-its-a-good-thing/) attribute.
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Accepts a “srcset” string and returns an array of objects with the possible properties: `url` (always), `width`, `height`, and `density`.
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#### string
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Type: `string`
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A “srcset” string.
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#### options
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Type: `object`
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##### strict
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Type: `boolean`\
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Default: `false`
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When enabled, an invalid “srcset” string will cause an error to be thrown. When disabled, a best effort will be made to parse the string, potentially resulting in invalid or nonsensical output.
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### .stringify(SrcSetDefinitions, options?)
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Stringify `SrcSetDefinition`s. Accepts an array of `SrcSetDefinition` objects and returns a “srcset” string.
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#### srcsetDescriptors
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Type: `array`
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An array of `SrcSetDefinition` objects. Each object should have a `url` field and may have `width`, `height` or `density` fields. When the `strict` option is `true`, only `width` or `density` is accepted.
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#### options
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Type: `object`
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##### strict
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Type: `boolean`
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Default: `false`
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Enable or disable validation of the SrcSetDefinitions. When true, invalid input will cause an error to be thrown. When false, a best effort will be made to stringify invalid input, likely resulting in invalid srcset value.
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---
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<div align="center">
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<b>
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<a href="https://tidelift.com/subscription/pkg/npm-srcset?utm_source=npm-srcset&utm_medium=referral&utm_campaign=readme">Get professional support for this package with a Tidelift subscription</a>
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</b>
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<br>
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<sub>
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Tidelift helps make open source sustainable for maintainers while giving companies<br>assurances about security, maintenance, and licensing for their dependencies.
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</sub>
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</div>
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