Best way to extract innerText around getSelection ()

Question

I am working on a Chrome extension that will extract a simple text url from a selection, but the selection will always be part of the URL, so I need to scan left and right. I need to extract 500 characters around the selection from innerText, since I do not want to parse the html elements, nor do I want to reassemble the textContent.

Here is what I have so far, it works very well, but I feel that there is a better way that does not change the document object and then restores it back to its original state ...

// create a random 8 digit number - or bigger since we don't want duplicates var randId = Math.floor(Math.random()*(90000000)[phone]); var selection = document.getSelection(); var selectionRange = selection.getRangeAt(0); // backup content, and then clone selection the user has made var selectionContents = selectionRange.cloneContents(); var selectionContentsTxt = selectionContents.textContent; // add random number to previous selection, this will expand selection selectionContents.textContent = randId; selectionRange.insertNode(selectionContents); // find the random number in the document (in innerText in document.body) var everything = document.body.innerText; var offset = everything.indexOf(randId); // restore backed up content to original state,- replace the selection selectionContents = selectionRange.extractContents(); selectionContents.textContent = selectionContentsTxt; selectionRange.insertNode(selectionContents); // now we have the selection location offset in document.body.innerText everything = document.body.innerText; var extract = everything.substring(offset-250, offset+250); 

Instance

contains the extracted text, line breaks, etc., which are evaluated by the browser. This, by the way, will be Chrome only because I do not need cross-compatibility at all. Now I can parse the selection - from the middle to the edges to find the URL, note that starting the parsing from the middle is important, so I didn’t just extract the innerText from the parentNode of my getSelection () without knowing the offset ...

Is there a better way to do this? maybe copying the whole document into DOMParser, but how can I apply getSelection from the original document to it?

------ UPDATE ------

I simplified the code above (forgot to mention that I work with mouse clicks to detect a click event, after double-clicking to select text) and now it finds caretOffset in document.body.innerText, but it still changes the document and then restores it, so still thinking of a better way to do it. I am wondering if insertNode and deleteContents are bad in some way?

 var randId = Math.floor(Math.random()*(90000000)[phone]); var range = document.caretRangeFromPoint(event.clientX, event.clientY); range.insertNode(document.createTextNode(randId)); var everything = document.body.innerText; var offset = everything.indexOf(randId); range.deleteContents(); var everything = document.body.innerText; var extract = everything.substring(offset-250, offset+250); document.getSelection().anchorNode.parentNode.normalize(); 

Any thoughts?