Webpacks build.js 的 OnLoad？

Question

I receive a build.js generated with webpack from other department. I include it in the HTML file with

<script type="module" src="build.js"></script>

But there are a number of asynchronous requests and variables in there that I need to access. I cannot access them until the build.js is completely loaded. How can I check when it has been loaded?

Answer 1

If build.js is your code and you are comfortable in editing it, then you could create a Promise which would automatically be fulfilled when the asynchronous tasks are completed. You can also use multiple promises and call all to ensure that all your variables are in place.

Example for Promise.all , taken from the documentation:

const promise1 = Promise.resolve(3);
const promise2 = 42;
const promise3 = new Promise((resolve, reject) => {
  setTimeout(resolve, 100, 'foo');
});

Promise.all([promise1, promise2, promise3]).then((values) => {
  console.log(values);
});
// expected output: Array [3, 42, "foo"]

If build.js is not something you are comfortable modifying, then you could read it or its documentation and find out whether there is an even hook for the event when its loading is completed.

If all else fails, then you can use setInterval to repeatedly check for all the resources that you need and once they are found, perform the operations you need along with clearInterval to stop the repeated check for them.