# <mutation-observer-import-mixin> Observer > a SuperClass mixin that dynamically imports undefined custom element definitions ## Usage To use this web component in your project you can utilize one of the following styles of syntax. ```js /* In an existing JS module / web component */ import '@lrnwebcomponents/mutation-observer-import-mixin/mutation-observer-import-mixin.js'; /* At top of an application with build routine */ /* Alternatives for top of application */ // via unpkg CDN (good for testing) ``` ## Develop / Demo Run `yarn start` will start a local development server, open your default browser to display it, open your finder to the correct window and start watching the `/src` directory for changes and automatically rebuilding the element and documentation site for the demo. ```bash $ yarn start ``` ## Test ```bash $ yarn run test ``` ## Build Builds ensure that wcfactory can correctly compile your web component project to work on the maximum number of browsers possible. ```bash $ yarn run build ``` ## Contributing 1. Fork it! `git clone https://github.com/elmsln/lrnwebcomponents.git` 2. Create your feature branch: `git checkout -b my-new-feature` 3. Commit your changes: `git commit -m 'Add some feature'` 4. Push to the branch: `git push origin my-new-feature` 5. Submit a pull request :D ## Code style Observer (and all lrnwebcomponents) use [Prettier][prettier] to auto-format JS and JSON. The style rules get applied when you commit a change. If you choose to, you can [integrate your editor][prettier-ed] with Prettier to have the style rules applied on every save. [prettier]: https://github.com/prettier/prettier/ [prettier-ed]: https://github.com/prettier/prettier/#editor-integration [polyserve]: https://github.com/Polymer/polyserve [web-component-tester]: https://github.com/Polymer/web-component-tester ## License [Apache-2.0 License](http://opensource.org/licenses/Apache-2.0).