Files
template/src/mixins/mutating.js
T
2018-03-30 10:51:26 -07:00

53 lines
1.6 KiB
JavaScript

// Copyright 2018 The Distill Template Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
export const Mutating = (superclass) => {
return class extends superclass {
constructor() {
super();
// set up mutation observer
const options = {childList: true, characterData: true, subtree: true};
const observer = new MutationObserver( () => {
observer.disconnect();
this.renderIfPossible();
observer.observe(this, options);
});
// ...and listen for changes
observer.observe(this, options);
}
connectedCallback() {
super.connectedCallback();
this.renderIfPossible();
}
// potential TODO: check if this is enough for all our usecases
// maybe provide a custom function to tell if we have enough information to render
renderIfPossible() {
if (this.textContent && this.root) {
this.renderContent();
}
}
renderContent() {
console.error(`Your class ${this.constructor.name} must provide a custom renderContent() method!` );
}
}; // end class
}; // end mixin function