How to replace word with javascript? - javascript

In some forum I join, they just replace some link with something like spam or deleted. Example: www.rapidshare.com/download/123 will automatically turn to www.spam.com/download/123 OR word MONEY will change to BOSS.
Its really annoyed me because I have to rename back manually if I want to download. Is there any Javascript that can solve this that will replace back www.spam.com to www.rapidshare.com? I mean in client side.
Thanks

If these URLs are in href attributes...
var replaceHrefAttributes = function (element, search, replace) {
var nodes = element.getElementsByTagName('a');
for (var i = 0, length = nodes.length; i < length; i++) {
var node = nodes[i];
if (node.href == undefined) {
continue;
}
node.href = node.href.replace(new RegExp(search, 'g'), replace);
}
}
Your usage may be something like...
replaceHrefAttributes(document.body, 'www.spam.com', 'www.rapidshare.com');
If these URLs are inline text...
You could iterate over all text nodes, using replace() to replace any string with another.
Here is a general purpose recursive function I've written to do this...
var replaceText = function replaceText(element, search, replace) {
var nodes = element.childNodes;
for (var i = 0, length = nodes.length; i < length; i++) {
var node = nodes[i];
if (node.childNodes.length) {
replaceText(node, search, replace);
continue;
}
if (node.nodeType != 3) {
continue;
}
node.data = node.data.replace(new RegExp(search, 'g'), replace);
}
}
Your usage may be something like...
replaceText(document.body, 'www.spam.com', 'www.rapidshare.com');
If you are curious as to how the code works, here is a brief explanation...
Get all child nodes of the element. This will get text nodes and elements.
Iterate over all of them.
If this node has child nodes of its own, call the function again with element as the element in the loop. continue because we can't modify this as it is not a text node.
If this node's nodeType property is not 3 (i.e. a text node), then continue as again we can't modify any text.
We are confident this is a text node now, so replace the text.
You could make this function more flexible by passing search straight to it, allowing it to search for text using a string or a regular expression.

var a = document.getElementsByTagName('a');
for (var i = 0, len = a.length ; i < len ; i += 1) {
a.firstChild.nodeValue = a.href;
}

Related

How to write Javascript to search nodes - without getElementsByClassName

I'm very new at recursion, and have been tasked with writing getElementsByClassName in JavaScript without libraries or the DOM API.
There are two matching classes, one of which is in the body tag itself, the other is in a p tag.
The code I wrote isn't working, and there must be a better way to do this. Your insight would be greatly appreciated.
var elemByClass = function(className) {
var result = [];
var nodes = document.body; //<body> is a node w/className, it needs to check itself.
var childNodes = document.body.childNodes; //then there's a <p> w/className
var goFetchClass = function(nodes) {
for (var i = 0; i <= nodes; i++) { // check the parent
if (nodes.classList == className) {
result.push(i);
console.log(result);
}
for (var j = 0; j <= childNodes; j++) { // check the children
if (childNodes.classList == className) {
result.push(j);
console.log(result);
}
goFetchClass(nodes); // recursion for childNodes
}
goFetchClass(nodes); // recursion for nodes (body)
}
return result;
};
};
There are some errors, mostly logical, in your code, here's what it should have looked like
var elemByClass = function(className) {
var result = [];
var pattern = new RegExp("(^|\\s)" + className + "(\\s|$)");
(function goFetchClass(nodes) {
for (var i = 0; i < nodes.length; i++) {
if ( pattern.test(nodes[i].className) ) {
result.push(nodes[i]);
}
goFetchClass(nodes[i].children);
}
})([document.body]);
return result;
};
Note the use of a regex instead of classList, as it makes no sense to use classList which is IE10+ to polyfill getElementsByClassName
Firstly, you'd start with the body, and check it's className property.
Then you'd get the children, not the childNodes as the latter includes text-nodes and comments, which can't have classes.
To recursively call the function, you'd pass the children in, and do the same with them, check for a class, get the children of the children, and call the function again, until there are no more children.
Here are some reasons:
goFetchClass needs an initial call after you've defined it - for example, you need a return goFetchClass(nodes) statement at the end of elemByClass function
the line for (var i = 0; i <= nodes; i++) { will not enter the for loop - did you mean i <= nodes.length ?
nodes.classList will return an array of classNames, so a direct equality such as nodes.classList == className will not work. A contains method is better.
Lastly, you may want to reconsider having 2 for loops for the parent and children. Why not have 1 for loop and then call goFetchClass on the children? such as, goFetchClass(nodes[i])?
Hope this helps.

Replace text in the middle of a TextNode with an element

I want to insert html tags within a text node with TreeWalker, but TreeWalker forces my html brackets into & lt; & gt; no matter what I've tried. Here is the code:
var text;
var tree = document.createTreeWalker(document.body,NodeFilter.SHOW_TEXT);
while (tree.nextNode()) {
text = tree.currentNode.nodeValue;
text = text.replace(/(\W)(\w+)/g, '$1<element onmouseover="sendWord(\'$2\')">$2</element>');
text = text.replace(/^(\w+)/, '<element onmouseover="sendWord(\'$1\')">$1</element>');
tree.currentNode.nodeValue = text;
}
Using \< or " instead of ' won't help. My workaround is to copy all of the DOM tree to a string and to replace the html body with that. It works on very simple webpages and solves my first problem, but is a bad hack and won't work on anything more than a trivial page. I was wondering if I could just work straight with the text node rather than use a workaround. Here is the code for the (currently buggy) workaround:
var text;
var newHTML = "";
var tree = document.createTreeWalker(document.body);
while (tree.nextNode()) {
text = tree.currentNode.nodeValue;
if (tree.currentNode.nodeType == 3){
text = text.replace(/(\W)(\w+)/g, '$1<element onmouseover="sendWord(\'$2\')">$2</element>');
text = text.replace(/^(\w+)/, '<element onmouseover="sendWord(\'$1\')">$1</element>');
}
newHTML += text
}
document.body.innerHTML = newHTML;
Edit: I realize a better workaround would be to custom tag the text nodes ((Customtag_Start_Here) etc.), copy the whole DOM to a string, and use my customs tags to identify text nodes and modify them that way. But if I don't have to, I'd rather not.
To 'change' a text node into an element, you must replace it with an element. For example:
var text = tree.currentNode;
var el = document.createElement('foo');
el.setAttribute('bar','yes');
text.parentNode.replaceChild( el, text );
If you want to retain part of the text node, and inject an element "in the middle", you need to create another text node and insert it and the element into the tree at the appropriate places in the tree.
Edit: Here's a function that might be super useful to you. :)
Given a text node, it runs a regex on the text values. For each hit that it finds it calls a custom function that you supply. If that function returns a string, then the match is replaced. However, if that function returns an object like:
{ name:"element", attrs{onmouseover:"sendWord('foo')"}, content:"foo" }
then it will split the text node around the match and inject an element in that location. You can also return an array of strings or those objects (and can recursively use arrays, strings, or objects as the content property).
Demo: http://jsfiddle.net/DpqGH/8/
function textNodeReplace(node,regex,handler) {
var mom=node.parentNode, nxt=node.nextSibling,
doc=node.ownerDocument, hits;
if (regex.global) {
while(node && (hits=regex.exec(node.nodeValue))){
regex.lastIndex = 0;
node=handleResult( node, hits, handler.apply(this,hits) );
}
} else if (hits=regex.exec(node.nodeValue))
handleResult( node, hits, handler.apply(this,hits) );
function handleResult(node,hits,results){
var orig = node.nodeValue;
node.nodeValue = orig.slice(0,hits.index);
[].concat(create(mom,results)).forEach(function(n){
mom.insertBefore(n,nxt);
});
var rest = orig.slice(hits.index+hits[0].length);
return rest && mom.insertBefore(doc.createTextNode(rest),nxt);
}
function create(el,o){
if (o.map) return o.map(function(v){ return create(el,v) });
else if (typeof o==='object') {
var e = doc.createElementNS(o.namespaceURI || el.namespaceURI,o.name);
if (o.attrs) for (var a in o.attrs) e.setAttribute(a,o.attrs[a]);
if (o.content) [].concat(create(e,o.content)).forEach(e.appendChild,e);
return e;
} else return doc.createTextNode(o+"");
}
}
It's not quite perfectly generic, as it does not support namespaces on attributes. But hopefully it's enough to get you going. :)
You would use it like so:
findAllTextNodes(document.body).forEach(function(textNode){
replaceTextNode( textNode, /\b\w+/g, function(match){
return {
name:'element',
attrs:{onmouseover:"sendWord('"+match[0]+"')"},
content:match[0]
};
});
});
function findAllTextNodes(node){
var walker = node.ownerDocument.createTreeWalker(node,NodeFilter.SHOW_TEXT);
var textNodes = [];
while (walker.nextNode())
if (walker.currentNode.parentNode.tagName!='SCRIPT')
textNodes.push(walker.currentNode);
return textNodes;
}
or if you want something closer to your original regex:
replaceTextNode( textNode, /(^|\W)(\w+)/g, function(match){
return [
match[1], // might be an empty string
{
name:'element',
attrs:{onmouseover:"sendWord('"+match[2]+"')"},
content:match[2]
}
];
});
Function that returns the parent element of any text node including partial match of passed string:
function findElByText(text, mainNode) {
let textEl = null;
const traverseNodes = function (n) {
if (textEl) {
return;
}
for (var nodes = n.childNodes, i = nodes.length; i--;) {
if (textEl) {
break;
}
var n = nodes[i], nodeType = n.nodeType;
// Its a text node, check if it matches string
if (nodeType == 3) {
if (n.textContent.includes(text)) {
textEl = n.parentElement;
break;
}
}
else if (nodeType == 1 || nodeType == 9 || nodeType == 11) {
traverseNodes(n);
}
}
}
traverseNodes(mainNode);
return textEl;
}
Usage:
findElByText('Some string in document', document.body);

How to remove specific characters in a particular element

How do i remove the character "," from a div. for example,
<div class="something">This, is, the, text. </div>
Now i want to remove all the ","s from that div using javascript.
Please forgive me for being too noob in javascript.
var elements = document.getElementsByClassName("something");
elements[0].innerHTML = elements[0].innerHTML.replace(/,/g,'');
Check this example out:
http://jsfiddle.net/QpJNZ/
Update:
var elements = document.getElementsByClassName("something");
for (var i = 0; i < elements.length; ++i) {
elements[i].innerHTML = elements[i].innerHTML.replace(/,/g,'');
}
This is how to make this work for more than one element.
Check this example out:
http://jsfiddle.net/VBEaQ/2/
If the element only contains text and no other elements, you can simply do get the inner content of the element then perform string replacement:
element.innerHTML = element.innerHTML.replace(/,/g, '');
To replace all occurrences of a character sequence, you have to use a regular expression with the global modifier.
If the element contains other elements, you can iterate over all child text nodes:
function replace(element, needle, repl) {
var children = element.childNodes, // get a list of child nodes
pattern = new RegExp(needle, 'g'), // prepare pattern
child, i, l;
for(i = 0, l = children.length; i < l; i++) {
child = children[i];
if(child.nodeType === 3) { // if we deal with a text node
child.nodeValue = child.nodeValue.replace(pattern, repl); // replace
}
}
}
Things to watch out for:
If the text you are searching for contains special regular expression characters, you have to properly escape them first.
If you want to replace the text inside child elements as well, you have to call this function recursively for each element node (nodeType is 1).
Reference: String.replace, Node.childNodes, Node.nodeType, Node.nodeValue, RegExp

Creating a regex that ignores everything inside <code> blocks

I'm adding emoticons to user input with:
function emoticons(html){
for(var emoticon in emotes){
for(var i = 0; i < emotes[emoticon].length; i++){
// Escape bad characters like )
var r = RegExp.escape(emotes[emoticon][i]);
// Set the regex up to replace all matches
r_escaped = new RegExp(r, "g");
// Replace the emote with the image
html = html.replace(r_escaped,"<img src=\""+icon_folder+"/face-"+emoticon+".png\" class=\"emoticonimg\" />");
}
}
return html;
}
The problem is sometimes the user input is in <code>xxx</code> blocks. Is there a way to get the emoticons function to ignore everything inside the code blocks if they exists. As they won't always exist?
Thanks
In order to do this easily, I'd work only with text nodes (not serialised HTML) and skip code elements.
You tagged it jquery, so there is some jQuery convenience code to ease cross browser issues with utility functions. It is very easily modified to work without jQuery, however.
var searchText = function(parentNode, regex, callback, skipElements) {
skipElements = skipElements || ['script', 'style'];
var node = parentNode.firstChild;
do {
if (node.nodeType == 1) {
var tag = node.tagName.toLowerCase();
if (~$.inArray(tag, skipElements)) {
continue;
}
searchText.call(this, node, regex, callback);
} else if (node.nodeType == 3) {
while (true) {
// Does this node have a match? If not, break and return.
if (!regex.test(node.data)) {
break;
}
node.data.replace(regex, function(match) {
var args = $.makeArray(arguments),
offset = args[args.length - 2],
newTextNode = node.splitText(offset);
callback.apply(window, [node].concat(args));
newTextNode.data = newTextNode.data.substr(match.length);
node = newTextNode;
});
}
}
} while (node = node.nextSibling);
};
searchText($('body')[0], /:\)/, function(node, match) {
var img = $('<img />')[0];
img.src = 'http://www.gravatar.com/avatar/80200e1488ab252197b7f0f51ae230ef?s=32&d=identicon&r=PG';
img.alt = match;
node.parentNode.insertBefore(img, node.nextSibling);
}, ['code']);
jsFiddle.
I wrote this function recently, it should do what you hope to achieve.

Javascript to replace text in Gmail message (Chrome Extension)

I'm trying to write a Chrome Extension which will replace a string of text in Gmail messages.
If I open a Gmail message and click the print button to see it in print view and run the extension it works well and replaces all instances of the string.
However, if I run the extension in the normal Gmail discussion view it causes the page to refresh and it does not actually replace any of the text.
Here is the code I'm using. Any ideas what I'm doing wrong?
function doIt(){
findAndReplace("Father","Mother");
}
var haystackText = "";
function findAndReplace(needle, replacement) {
if (haystackText.length == 0) {
haystackText = document.body.innerHTML;
}
var match = new RegExp(needle, "ig");
var replaced = "";
if (replacement.length > 0) {
replaced = haystackText.replace(match, replacement);
document.body.innerHTML = replaced;
}
}
doIt();
Update:
Here is the updated code I'm using after Felix Kling's help. Similar issue to the one above, it works in print preview but not in the regular Gmail view. It does not however reload the page.
function findAndReplace(root, needle, replacement) {
var children = root.childNodes;
var pattern = new RegExp(needle, 'ig');
var node;
for(var i = 0, l = children.length; i < l; i++) {
node = children[i];
if(node.nodeType === 3) { // we have a text node
node.nodeValue = node.nodeValue.replace(pattern, replacement);
} else if(node.nodeType === 1) { // Element node
findAndReplace(node, needle, replacement);
}
}
}
function doIt(){
findAndReplace(document,"Father","Mother");
}
doIt();
It's because you are changing the whole document. You are basically destroying and creating every element of the page.
document.body.innerHTML = replaced;
inserts every element of the page anew, so all JavaScript code is executed again etc.
You should only change those text nodes that contain the text you are looking for. That means you have to recursively traverse the DOM (not the whole, start at the message list), test the node type and value and perform the necessary actions.
Update: Example
function findAndReplace(root, needle, replacement) {
var children = root.childNodes,
pattern = new RegExp(needle, 'ig');
node;
for(var i = 0, l = childNodes.length; i < l; i++) {
node = children[i];
if(node.nodeType === 3) { // we have a text node
node.nodeValue = node.nodeValue.replace(pattern, replacement);
} else if(node.nodeType === 1) { // Element node
findAndReplace(node, needle, replacement);
}
}
}
This is a simple example. I actually don't know how well it performs, but I think you have no other choice. Further things to consider are e.g. escaping special regular expressions characters in the search string.
To learn more about JavaScript and DOM, I recommend to read:
MDN - JavaScript Guide
MDN - DOM reference (espcially the introduction)

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