Author: John Au-Yeung

Sometimes, we want to fake click to activate an onclick method with JavaScript.

In this article, we’ll look at how to fake click to activate an onclick method with JavaScript.

How to fake click to activate an onclick method with JavaScript?

To fake click to activate an onclick method with JavaScript, we call the click method.

For instance, we write

document.getElementById("link").click();

to get the element we want to click with getElementById.

Then we call click on it to trigger the click.

Conclusion

To fake click to activate an onclick method with JavaScript, we call the click method.

Sometimes, we want to check if a JSON is empty in Node.js and JavaScript.

In this article, we’ll look at how to check if a JSON is empty in Node.js and JavaScript.

How to check if a JSON is empty in Node.js and JavaScript?

To check if a JSON is empty in Node.js and JavaScript, we use the Object.keys method.

For instance, we write

const empty = Object.keys(myObj).length === 0;

to get an array of property keys in the myObj object with Object.keys.

Then we check if it’s empty by checking if length is 0.

Conclusion

To check if a JSON is empty in Node.js and JavaScript, we use the Object.keys method.

Sometimes, we want to convert a string into a math operator in JavaScript.

In this article, we’ll look at how to convert a string into a math operator in JavaScript.

How to convert a string into a math operator in JavaScript?

To convert a string into a math operator in JavaScript, we use the mathjs package.

For instance, we write

npm install mathjs

Then we write

import { evaluate } from "mathjs";

const myArray = ["225", "+", "15", "-", "10"];
const result = evaluate(myArray.join(" "));

to call evaluate with the string created by combining the substrings into 1 string with join to get the result of the expression.

Conclusion

To convert a string into a math operator in JavaScript, we use the mathjs package.

Sometimes, we want to do something after all files are uploaded with dropzone.js and JavaScript.

In this article, we’ll look at how to do something after all files are uploaded with dropzone.js and JavaScript.

How to do something after all files are uploaded with dropzone.js and JavaScript?

To do something after all files are uploaded with dropzone.js and JavaScript, we listen for the complete event.

For instance, we write

Dropzone.options.filedrop = {
  init() {
    this.on("complete", (file) => {
      if (
        this.getUploadingFiles().length === 0 &&
        this.getQueuedFiles().length === 0
      ) {
        doSomething();
      }
    });
  },
};

to set the Dropzone.options.filedrop.init property to listen to the complete event with the 'on' method.

In the event listener, we get the uploading file’s length and queued file’s length and check if they’re 0.

If they are, then all file uploads are done.

Conclusion

To do something after all files are uploaded with dropzone.js and JavaScript, we listen for the complete event.

Sometimes, we want to use axios download file stream and write file with Node.js and JavaScript.

In this article, we’ll look at how to use axios download file stream and write file with Node.js and JavaScript.

How to use axios download file stream and write file with Node.js and JavaScript?

To use axios download file stream and write file with Node.js and JavaScript, we set the responseType to 'stream'.

For instance, we write

const response = await axios({
  method: "get",
  url: "https://example.com/my.pdf",
  responseType: "stream",
});
response.data.pipe(fs.createWriteStream("/temp/my.pdf"));

to call axios to make a get request to a file.

We set the responseType to 'stream' so axios returns a promise with the file’s stream.

Then we call response.data.pipe with fs.createWriteStream("/temp/my.pdf") to save the stream to /temp/my.pdf.

Conclusion

To use axios download file stream and write file with Node.js and JavaScript, we set the responseType to 'stream'.