Category: JavaScript

Sometimes, we want to fix Error: Cannot resolve module ‘style-loader’ with JavaScript.

In this article, we’ll look at how to fix Error: Cannot resolve module ‘style-loader’ with JavaScript.

How to fix Error: Cannot resolve module ‘style-loader’ with JavaScript?

To fix Error: Cannot resolve module ‘style-loader’ with JavaScript, we install style-loader and add it to the Webpack config.

To install it, we run

npm install style-loader css-loader --save

to install the style-loader and css-loader packages.

Then in our Webpack config file, we write

module.exports = {
  //...
  module: {
    loaders: [
      {
        test: /\.jsx?$/,
        loader: "babel-loader",
        include: path.join(_dirname, "app"),
      },
      {
        test: /\.css$/,
        loader: "style-loader!css-loader",
      },
    ],
    resolve: {
      extensions: ["", ".js", ".jsx", ".css"],
    },
  },
};

to use the css-loader for importing CSS fiiles.

Conclusion

To fix Error: Cannot resolve module ‘style-loader’ with JavaScript, we install style-loader and add it to the Webpack config.

Sometimes, we want to save canvas as png image with JavaScript.

In this article, we’ll look at how to save canvas as png image with JavaScript.

How to save canvas as png image with JavaScript?

To save canvas as png image with JavaScript, we can use the FileSaver.js library.

We install it with

npm install file-saver --save

Then we use it by writing

import { saveAs } from "file-saver";

const canvas = document.getElementById("my-canvas");

//...

canvas.toBlob((blob) => {
  saveAs(blob, "image.png");
});

We select the canvas with getElementById.

Then we call canvas.toBlob with a callback that calls saveAs to save the blob with the canvas content to image.png.

Conclusion

To save canvas as png image with JavaScript, we can use the FileSaver.js library.

Sometimes, we want to get an object’s methods with JavaScript.

In this article, we’ll look at how to get an object’s methods with JavaScript.

How to get an object’s methods with JavaScript?

To get an object’s methods with JavaScript, we can use the array filter method and Object.keys method.

For instance, we write

const myObj = { myFn() {}, abc: true };
const allKeys = Object.keys(myObj);
const fnKeys = allKeys.filter((key) => typeof myObj[key] == "function");
console.log(fnKeys);

to call Object.keys with myObj to get an array of property kets in myObj as a string array.

Then we call allKeys.filter with a callback that checks if myObj[key] is a function with the typeof operator.

And an array of method keys are returned by filter.

Conclusion

To get an object’s methods with JavaScript, we can use the array filter method and Object.keys method.

Sometimes, we want to find by key deep in a nested array with JavaScript.

In this article, we’ll look at how to find by key deep in a nested array with JavaScript.

How to find by key deep in a nested array with JavaScript?

To find by key deep in a nested array with JavaScript, we can recursively search each level of the nested array.

For instance, we write

const deepSearchByKey = (object, originalKey, matches = []) => {
  if (object !== null) {
    if (Array.isArray(object)) {
      for (const arrayItem of object) {
        deepSearchByKey(arrayItem, originalKey, matches);
      }
    } else if (typeof object === "object") {
      for (const key of Object.keys(object)) {
        if (key === originalKey) {
          matches.push(object);
        } else {
          deepSearchByKey(object[key], originalKey, matches);
        }
      }
    }
  }

  return matches;
};

to define the deepSearchByKey function.

In it, we check if object isn’t null.

If it is, then we check if object is an array with Array.isArray.

If it is, then we call deepSearchByKey to search for the key we’re looking for.

Otherwise, if object is an object, which we check with typeof object === "object", then we loop through the keys of the object that we get from Object.keys.

If key equals originalKey then we push the object to matches.

Otherwise, we call deepSearchByKey to search the object[key] object.

Conclusion

To find by key deep in a nested array with JavaScript, we can recursively search each level of the nested array.

Sometimes, we want to declare array of objects with JavaScript.

In this article, we’ll look at how to declare array of objects with JavaScript.

How to declare array of objects with JavaScript?

To declare array of objects with JavaScript, we can use the array fill method.

For instance, we write

const arr = new Array(5).fill({ test: "a" });

to create an array with 5 empty slots with Array(5).

Then we call fill with each slot with the { test: "a" } object.

Conclusion

To declare array of objects with JavaScript, we can use the array fill method.