Javascript - how to get the index of an HTML tag using domparser()?

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I need to parse data from an HTML file using DOMParser(). This is the file's structure:

HTML

...
<p>text to ignore</p>
<p>text to ignore</p>
<p>text to ignore</p>
<br/>
<p>text to ignore</p>
<p>text to ignore</p>
<p>text to ignore</p>
<br/>
<p>text to parse</p>
<p>text to parse</p>
<p>text to parse</p>
...

How can I get the index of last "br/" tag, in order to parse all the "p" elements after it?

What I have tried:

JavaScript

var doc = new DOMParser().parseFromString(file, "text/html");
var LastBrIndex = doc.lastIndexOf("<br/>");

TypeError: doc.lastIndexOf is not a function

Posted 8-Aug-23 3:53am

LB2371

Updated 10-Aug-23 6:36am

Deeksha Shenoy

v2

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2 solutions

Solution 1

See Document - Web APIs | MDN[^] for valid methods to access the HTML DOM.

Posted 8-Aug-23 5:48am

Richard MacCutchan

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Richard Deeming · Accepted Answer · 2023-08-09T02:21:00

Assuming all of the elements are siblings, as shown in your question, then you can use the :last-of-type[^] selector to find the last <br> element, and then iterate over its following siblings.

For example:

JavaScript

const doc = new DOMParser().parseFromString(file, "text/html");
const lastBr = doc.querySelector("br:last-of-type");

const elementsToProcess = [];
let el = lastBr ? lastBr.nextElementSibling : doc.firstChild;
while (el) {
    if (el.tagName === "P") { elementsToProcess.push(el); }
    el = el.nextElementSibling;
}

Demo[^]