function handleTextNode(textNode) {
if(textNode.nodeName !== '#text'
|| textNode.parentNode.nodeName === 'SCRIPT'
|| textNode.parentNode.nodeName === 'STYLE'
) {
//Don't do anything except on text nodes, which are not children
// of <script> or <style>.
return;
}
let origText = textNode.textContent;
let newHtml=origText.replace(/river/g,'<a href="http://www.cnn.com">asdf</a>');
//Only change the DOM if we actually made a replacement in the text.
//Compare the strings, as it should be faster than a second RegExp operation and
// lets us use the RegExp in only one place for maintainability.
if( newHtml !== origText) {
let newSpan = document.createElement('span');
newSpan.innerHTML = newHtml;
textNode.parentNode.replaceChild(newSpan,textNode);
}
}
//Testing: Walk the DOM of the <body> handling all non-empty text nodes
function processDocument() {
//Create the TreeWalker
let treeWalker = document.createTreeWalker(document.body, NodeFilter.SHOW_TEXT,{
acceptNode: function(node) {
if(node.textContent.length === 0) {
//Alternately, could filter out the <script> and <style> text nodes here.
return NodeFilter.FILTER_SKIP; //Skip empty text nodes
} //else
return NodeFilter.FILTER_ACCEPT;
}
}, false );
//Make a list of the text nodes prior to modifying the DOM. Once the DOM is
// modified the TreeWalker will become invalid (i.e. the TreeWalker will stop
// traversing the DOM after the first modification).
let nodeList=[];
while(treeWalker.nextNode()){
nodeList.push(treeWalker.currentNode);
}
//Iterate over all text nodes, calling handleTextNode on each node in the list.
nodeList.forEach(function(el){
handleTextNode(el);
});
}
document.getElementById('clickTo').addEventListener('click',processDocument,false);