Using DOMParser to Parse HTML Strings

I was playing with the WP Rest API plugin to access content from a WordPress blog into an Ionic 2 app. The WP Rest API returns an HTML string for the content of posts, which can make it hard to deal with. Fortunately though, the DOMParser Web API makes it easy to parse html strings into a fully formed DOM.

First you instantiate a new DOMParser instance and pass it your HTML string using parseFromString(). For this example, let’s say that we stored the HTML string in a variable called htmlContent:

let parser = new DOMParser();
let parsedHtml = parser.parseFromString(htmlContent, 'text/html');

And now parsedHtml is a DOM object that can be interacted with. Let’s extract a few things from it:

// The src of the first image:
let firstImg = parsedHtml.images[0].src;

// The li elements of the second ul element:
let liElements = parsedHtml.getElementsByTagName("ul")[1].children;

Taking the second example with li elements, let’s go a bit further and populate an array with the inner HTML of each element:

let rawLiElements = parsedHtml.getElementsByTagName("ul")[1].children;
let liElements = [];

👉 DOMParser is still experimental, so its implementation is subject to change and support can be limited.