JavaScript: findElementContains(elmName, needle) -- a function, allowing to find the deepest HTML element of given tag name, containing the text node with given text

findElementContains.js

function findElementContains(elmName, needle) {

	var foundTextNode = null;
	var allElms = document.querySelectorAll("*");
	for (var i=0; i < allElms.length; i++) {
		var allChildren = allElms[i].childNodes;
		for (var j=0; j < allChildren.length; j++) {
			if (allChildren[j].nodeType == 3 && allChildren[j].nodeValue.indexOf(needle) > -1) { // text node
				foundTextNode = allChildren[j];
				break;
			}
		}
	}

	if (foundTextNode) {

		var nextParent = foundTextNode.parentNode;
		while(nextParent) {
			if (nextParent.tagName.toLowerCase()==elmName.toLowerCase()) {
				return nextParent;
			}
			nextParent = nextParent.parentNode;
		}
	}

	return undefined;
}