================
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[](http://badge.fury.io/js/css-keyframer)
[](https://david-dm.org/tsuyoshiwada/css-keyframer/)
Dynamic css animation keyframes Manipulation library.
See demo page: https://tsuyoshiwada.github.io/css-keyframer/
## Description
css-keyframer.js provides a Low-level API that add to the head element dynamically generates a style element.
Therefore, linking to the DOM element must be handled by the user side.
### WHY?
When you want to apply the same animation to multiple elements, it is inefficient to update the in-line style of all the elements.
If you reuse one of `@keyframes` it can be realized efficient animation.
## Install
You can install the [css-keyframer.js](https://www.npmjs.com/package/css-keyframer) from [npm](https://www.npmjs.com/).
```bash
$ npm install css-keyframer --save
```
or Download the [css-keyframer.min.js](https://raw.githubusercontent.com/tsuyoshiwada/css-keyframer/master/css-keyframer.min.js)
## Getting started
In the following example, to apply the spin animation to `div.element`.
```html
```
```javascript
import CSSKeyframer from "css-keyframer";
const keyframer = new CSSKeyframer({ /* options */ });
// CSS property will be added vendor-prefix is automatically!
keyframer.register("spin", [
{ transform: "rotate(0deg)" },
{ transform: "rotate(360deg)" }
]);
document.querySelector(".element").style[keyframer.animationProp.js] = "spin 1500ms linear infinite";
```
### Options
To the constructor of `CSSKeyframer` You can specify the following options.
| Key | Default | Description |
|:----------------|:-------------------|:------------------------------------------------------------------------------------------------------------------------------|
| `namePrefix` | `""` | Grant prefix to `@keyframes`. |
| `styleDataName` | `"data-keyframes"` | To specify the attributes to be used in the style element. |
| `pretty` | `false` | Output pretty code `@keyframes`. Primarily used for debugging applications. |
| `useAgent` | `null` | Specify the UserAgent to be used for inline-style-prefixer. When set to `null`, it is judged automatically. **since: v1.0.0** |
## API
### getKeyframesString(name: string, keyframe: Object | Array): string
**since: v1.0.0**
Get CSS string containing the keyframes.
```javascript
keyframer.getKeyframesString("spin", {
"0%": { transform: "rotate(0deg)" },
"100%": { transform: "rotate(360deg)" }
});
// or Array style
keyframer.getKeyframesString("spin", [
{ transform: "rotate(0deg)" },
{ transform: "rotate(360deg)" }
]);
// Result (pretty: true)
// @keyframes spin {
// 0% {
// transform: rotate(0deg);
// }
// 100% {
// transform: rotate(360deg);
// }
// }
```
### getKeyframeStylesheet(name: string, keyframe: Object | Array): string
**since: v1.0.0**
Get a style element containing a keyframe as a string.
It is an API that you do not normally use. But, this is a useful API for Server-side Rendering.
```javascript
keyframer.getKeyframeStylesheet("spin", {
"0%": { transform: "rotate(0deg)" },
"100%": { transform: "rotate(360deg)" }
});
// or Array style
keyframer.getKeyframeStylesheet("spin", [
{ transform: "rotate(0deg)" },
{ transform: "rotate(360deg)" }
]);
// Result (pretty: true)
//
```
### register(name: string, keyframe: Object | Array): void
Register the `@keyframes`.
If `@keyframes` of the same name exists overwrites it.
**Example:**
```javascript
// Object style
keyframer.register("spin", {
"0%": { transform: "rotate(0deg)" },
"100%": { transform: "rotate(360deg)" }
});
// or Array style
keyframer.register("spin", [
{ transform: "rotate(0deg)" },
{ transform: "rotate(360deg)" }
]);
// Result (pretty: true)
//
```
### unregister(name: string): void
Unregister the `@keyframes`.
**Example:**
```javascript
keyframer.unregister("spin");
```
### unregisterAll(): void
Unregister all `@keyframes`.
**Example:**
```javascript
keyframer.unregisterAll();
```
### contains(name: string): boolean
Check whether the specified @keyframes exists.
**Example:**
```javascript
keyframer.contains("spin"); // true or false
```
### animationProp: { js: string, css: string }
**since: v1.0.0**
It provides the name of the property required for the animation of the set with a vendor prefix. (CSS and JS)
**Example:**
```javascript
import CSSKeyframer from "css-keyframer";
const keyframer = new CSSKeyframer();
keyframer.register("spin", [
{ transform: "rotate(0deg)" },
{ transform: "rotate(360deg)" }
]);
document.querySelector(".target").style[keyframer.animationProp.js] = "spin 1500ms linear infinite";
```
## License
Released under the [MIT Licence](./LICENSE)
## ChangeLog
See [CHANGELOG.md](./CHANGELOG.md).
## Author
[tsuyoshiwada](https://github.com/tsuyoshiwada)
## Development
Initialization of the project.
```bash
$ cd /your/project/dir
$ git clone https://github.com/tsuyoshiwada/css-keyframer.git
```
Install some dependencies.
```bash
$ npm install
```
Start the development and can you see demo page (access to the `http://localhost:3000/`).
```bash
$ npm start
```
Run lint and testing.
```bash
$ npm test
```
Generates build file.
```bash
$ npm run build
```
## Contribution
Thank you for your interest in css-keyframer.js.
Bugs, feature requests and comments are more than welcome in the [issues](https://github.com/tsuyoshiwada/css-keyframer/issues).
**Before you open a PR:**
Be careful to follow the code style of the project. Run `npm test` after your changes and ensure you do not introduce any new errors or warnings.
All new features and changes need documentation.
Thanks!