Problem
When making a file drag and drop box as the example below, we need to add event listeners like dragenter drop to the HTML element.
Solution
The solution is to add the listeners to this.theAliasOfTheElement, and then bind the reference to the element in the render function.
Code
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| import React from "react";
import PropTypes from "prop-types";
const style = {
width: "100%",
height: "100%",
backgroundColor: "yellow",
textAlign: "center",
padding: 40,
};
export default class MyDragAndDrop extends React.PureComponent {
constructor(props) {
super(props);
}
componentDidMount() {
this.dropBox.addEventListener("dragenter", this.onDragEnter);
this.dropBox.addEventListener("dragleave", this.onDragleave);
this.dropBox.addEventListener("drop", this.onDrop);
this.dropBox.addEventListener("dragover", this.onDragOver);
}
componentWillUnmount() {
this.dropBox.removeEventListener("dragenter", this.onDragEnter);
this.dropBox.removeEventListener("dragleave", this.onDragleave);
this.dropBox.removeEventListener("drop", this.onDrop);
this.dropBox.removeEventListener("dragover", this.onDragOver);
}
onDragOver = event => {
event.stopPropagation();
event.preventDefault();
return false;
};
onDragEnter = event => {
event.stopPropagation();
event.preventDefault();
console.debug("dragEnter");
return false;
};
onDragleave = event => {
event.stopPropagation();
event.preventDefault();
console.debug("dragLeft");
return false;
};
onDrop = event => {
event.stopPropagation();
event.preventDefault();
console.debug("drop");
return false;
};
render() {
return (
<div ref={elem => this.dropBox = elem} style={style}>
Drag and drop files here
</div>
);
}
}
|
Result
BEAUTIFUL! I should be a designer :)
EOF