Remove image by src - javascript

I need to remove certain images with a specific src:
http://ukn.cs-mtc.com/wp-content/plugins/download-monitor/page-addon/thumbnail.gif
Is there a way to remove the whole <img> tag with JavaScript?

I had some free time (and a strange urge to write some JavaScript...), so I thought I'd offer this functional approach:
function removeNeighbour(el, elType) {
if (!el) {
return false;
}
else if (el.nextElementSibling) {
var nxt = el.nextElementSibling;
}
else {
var nxt = el.nextSibling;
while (nxt.nodeType !== 1 && nxt.nextSibling) {
nxt = nxt.nextSibling;
}
}
if (elType && nxt.tagName.toLowerCase() == elType.toLowerCase()) {
nxt.parentNode.removeChild(nxt);
}
else if (!elType) {
nxt.parentNode.removeChild(nxt);
}
}
function clearElsWithAttrEquals(el, attr, val, andNeighbour, neighbourType) {
if (!el || !attr || !val) {
return false;
}
else if (document.querySelectorAll) {
var matchingElems = document.querySelectorAll(el + '[' + attr + '="' + val + '"]'),
neighbourType = neighbourType || '';
for (var i = matchingElems.length - 1; i >= 0; i--) {
if (andNeighbour === true) {
removeNeighbour(matchingElems[i], neighbourType);
}
matchingElems[i].parentNode.removeChild(matchingElems[i]);
}
}
else {
var matchingElems = document.getElementsByTagName(el),
len = (matchingElems.length - 1);
for (var i = len; i >= 0; i--) {
if (matchingElems[i][attr] == val) {
matchingElems[i].parentNode.removeChild(matchingElems[i]);
}
}
}
}
clearElsWithAttrEquals('img', 'src', 'http://ukn.cs-mtc.com/wp-content/plugins/download-monitor/page-addon/thumbnail.gif', true, 'p');​​​
JS Fiddle demo.
Quick guide to (and the only documentation I'm ever likely to write for) clearElsWithAttrEquals() function:
clearElsWithAttrEquals(el, attr, val[, andNeighbour[, neighbourType]]);
el : (string) identifies the element type ('img','p','span'...).
attr : (string) identifies which attribute you want to search by ('id', 'src', etc...)
val : (string) this will only match if the value is exactly equal to the string
andNeighbour : (Boolean, optional) do you want to remove the neighbouring element too? Pass true (if yes) or false (if not).
neighbourType : (string, optional) remove the neighbour only if it's of this element-type ('div','hr','span', etc) ; if omitted then the next sibling element will be removed regardless of its type.
References:
document.querySelectorAll() (Compatibility).
nextElementSibling (Compatibility).
nextSibling (Compatibility).
node.nodeType (Compatibility).
parentNode (Compatibility).
removeChild() (Compatibility).
String.toLowerCase().
while (condition) {/*...*/}.

Do you use jQuery? If so,
$('img[src="http://ukn.cs-mtc.com/wp-content/plugins/download-monitor/page-addon/thumbnail.gif"]').remove(); should work.
Otherwise...
var img = document.getElementsByTagName('img');
for(var i=0,i<img.length;i++) {
if(img[i].src == 'http://ukn.cs-mtc.com/wp-content/plugins/download-monitor/page-addon/thumbnail.gif') {
img[i].parentNode.removeChild(img[i]);
}
}

This can be done easily with jQuery:
$('img[src="<path>"]').remove();

Related

How to get the highest level parent of clicked element [duplicate]

HTML
<body>
<div class="lol">
<a class="rightArrow" href="javascriptVoid:(0);" title"Next image">
</div>
</body>
Pseudo Code
$(".rightArrow").click(function() {
rightArrowParents = this.dom(); //.dom(); is the pseudo function ... it should show the whole
alert(rightArrowParents);
});
Alert message would be:
body div.lol a.rightArrow
How can I get this with javascript/jquery?
Here is a native JS version that returns a jQuery path. I'm also adding IDs for elements if they have them. This would give you the opportunity to do the shortest path if you see an id in the array.
var path = getDomPath(element);
console.log(path.join(' > '));
Outputs
body > section:eq(0) > div:eq(3) > section#content > section#firehose > div#firehoselist > article#firehose-46813651 > header > h2 > span#title-46813651
Here is the function.
function getDomPath(el) {
var stack = [];
while ( el.parentNode != null ) {
console.log(el.nodeName);
var sibCount = 0;
var sibIndex = 0;
for ( var i = 0; i < el.parentNode.childNodes.length; i++ ) {
var sib = el.parentNode.childNodes[i];
if ( sib.nodeName == el.nodeName ) {
if ( sib === el ) {
sibIndex = sibCount;
}
sibCount++;
}
}
if ( el.hasAttribute('id') && el.id != '' ) {
stack.unshift(el.nodeName.toLowerCase() + '#' + el.id);
} else if ( sibCount > 1 ) {
stack.unshift(el.nodeName.toLowerCase() + ':eq(' + sibIndex + ')');
} else {
stack.unshift(el.nodeName.toLowerCase());
}
el = el.parentNode;
}
return stack.slice(1); // removes the html element
}
Using jQuery, like this (followed by a solution that doesn't use jQuery except for the event; lots fewer function calls, if that's important):
$(".rightArrow").click(function () {
const rightArrowParents = [];
$(this)
.parents()
.addBack()
.not("html")
.each(function () {
let entry = this.tagName.toLowerCase();
const className = this.className.trim();
if (className) {
entry += "." + className.replace(/ +/g, ".");
}
rightArrowParents.push(entry);
});
console.log(rightArrowParents.join(" "));
return false;
});
Live example:
$(".rightArrow").click(function () {
const rightArrowParents = [];
$(this)
.parents()
.addBack()
.not("html")
.each(function () {
let entry = this.tagName.toLowerCase();
const className = this.className.trim();
if (className) {
entry += "." + className.replace(/ +/g, ".");
}
rightArrowParents.push(entry);
});
console.log(rightArrowParents.join(" "));
return false;
});
<div class=" lol multi ">
Click here
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
(In the live examples, I've updated the class attribute on the div to be lol multi to demonstrate handling multiple classes.)
That uses parents to get the ancestors of the element that was clicked, removes the html element from that via not (since you started at body), then loops through creating entries for each parent and pushing them on an array. Then we use addBack to add the a back into the set, which also changes the order of the set to what you wanted (parents is special, it gives you the parents in the reverse of the order you wanted, but then addBack puts it back in DOM order). Then it uses Array#join to create the space-delimited string.
When creating the entry, we trim className (since leading and trailing spaces are preserved, but meaningless, in the class attribute), and then if there's anything left we replace any series of one or more spaces with a . to support elements that have more than one class (<p class='foo bar'> has className = "foo bar", so that entry ends up being p.foo.bar).
Just for completeness, this is one of those places where jQuery may be overkill, you can readily do this just by walking up the DOM:
$(".rightArrow").click(function () {
const rightArrowParents = [];
for (let elm = this; elm; elm = elm.parentNode) {
let entry = elm.tagName.toLowerCase();
if (entry === "html") {
break;
}
const className = elm.className.trim();
if (className) {
entry += "." + className.replace(/ +/g, ".");
}
rightArrowParents.push(entry);
}
rightArrowParents.reverse();
console.log(rightArrowParents.join(" "));
return false;
});
Live example:
$(".rightArrow").click(function () {
const rightArrowParents = [];
for (let elm = this; elm; elm = elm.parentNode) {
let entry = elm.tagName.toLowerCase();
if (entry === "html") {
break;
}
const className = elm.className.trim();
if (className) {
entry += "." + className.replace(/ +/g, ".");
}
rightArrowParents.push(entry);
}
rightArrowParents.reverse();
console.log(rightArrowParents.join(" "));
return false;
});
<div class=" lol multi ">
Click here
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js"></script>
There we just use the standard parentNode property (or we could use parentElement) of the element repeatedly to walk up the tree until either we run out of parents or we see the html element. Then we reverse our array (since it's backward to the output you wanted), and join it, and we're good to go.
I needed a native JS version, that returns CSS standard path (not jQuery), and deals with ShadowDOM. This code is a minor update on Michael Connor's answer, just in case someone else needs it:
function getDomPath(el) {
if (!el) {
return;
}
var stack = [];
var isShadow = false;
while (el.parentNode != null) {
// console.log(el.nodeName);
var sibCount = 0;
var sibIndex = 0;
// get sibling indexes
for ( var i = 0; i < el.parentNode.childNodes.length; i++ ) {
var sib = el.parentNode.childNodes[i];
if ( sib.nodeName == el.nodeName ) {
if ( sib === el ) {
sibIndex = sibCount;
}
sibCount++;
}
}
// if ( el.hasAttribute('id') && el.id != '' ) { no id shortcuts, ids are not unique in shadowDom
// stack.unshift(el.nodeName.toLowerCase() + '#' + el.id);
// } else
var nodeName = el.nodeName.toLowerCase();
if (isShadow) {
nodeName += "::shadow";
isShadow = false;
}
if ( sibCount > 1 ) {
stack.unshift(nodeName + ':nth-of-type(' + (sibIndex + 1) + ')');
} else {
stack.unshift(nodeName);
}
el = el.parentNode;
if (el.nodeType === 11) { // for shadow dom, we
isShadow = true;
el = el.host;
}
}
stack.splice(0,1); // removes the html element
return stack.join(' > ');
}
Here is a solution for exact matching of an element.
It is important to understand that the selector (it is not a real one) that the chrome tools show do not uniquely identify an element in the DOM. (for example it will not distinguish between a list of consecutive span elements. there is no positioning/indexing info)
An adaptation from a similar (about xpath) answer
$.fn.fullSelector = function () {
var path = this.parents().addBack();
var quickCss = path.get().map(function (item) {
var self = $(item),
id = item.id ? '#' + item.id : '',
clss = item.classList.length ? item.classList.toString().split(' ').map(function (c) {
return '.' + c;
}).join('') : '',
name = item.nodeName.toLowerCase(),
index = self.siblings(name).length ? ':nth-child(' + (self.index() + 1) + ')' : '';
if (name === 'html' || name === 'body') {
return name;
}
return name + index + id + clss;
}).join(' > ');
return quickCss;
};
And you can use it like this
console.log( $('some-selector').fullSelector() );
Demo at http://jsfiddle.net/gaby/zhnr198y/
The short vanilla ES6 version I ended up using:
Returns the output I'm used to read in Chrome inspector e.g body div.container input#name
function getDomPath(el) {
let nodeName = el.nodeName.toLowerCase();
if (el === document.body) return 'body';
if (el.id) nodeName += '#' + el.id;
else if (el.classList.length)
nodeName += '.' + [...el.classList].join('.');
return getDomPath(el.parentNode) + ' ' + nodeName;
};
I moved the snippet from T.J. Crowder to a tiny jQuery Plugin. I used the jQuery version of him even if he's right that this is totally unnecessary overhead, but i only use it for debugging purpose so i don't care.
Usage:
Html
<html>
<body>
<!-- Two spans, the first will be chosen -->
<div>
<span>Nested span</span>
</div>
<span>Simple span</span>
<!-- Pre element -->
<pre>Pre</pre>
</body>
</html>
Javascript
// result (array): ["body", "div.sampleClass"]
$('span').getDomPath(false)
// result (string): body > div.sampleClass
$('span').getDomPath()
// result (array): ["body", "div#test"]
$('pre').getDomPath(false)
// result (string): body > div#test
$('pre').getDomPath()
Repository
https://bitbucket.org/tehrengruber/jquery.dom.path
I've been using Michael Connor's answer and made a few improvements to it.
Using ES6 syntax
Using nth-of-type instead of nth-child, since nth-of-type looks for children of the same type, rather than any child
Removing the html node in a cleaner way
Ignoring the nodeName of elements with an id
Only showing the path until the closest id, if any. This should make the code a bit more resilient, but I left a comment on which line to remove if you don't want this behavior
Use CSS.escape to handle special characters in IDs and node names
~
export default function getDomPath(el) {
const stack = []
while (el.parentNode !== null) {
let sibCount = 0
let sibIndex = 0
for (let i = 0; i < el.parentNode.childNodes.length; i += 1) {
const sib = el.parentNode.childNodes[i]
if (sib.nodeName === el.nodeName) {
if (sib === el) {
sibIndex = sibCount
break
}
sibCount += 1
}
}
const nodeName = CSS.escape(el.nodeName.toLowerCase())
// Ignore `html` as a parent node
if (nodeName === 'html') break
if (el.hasAttribute('id') && el.id !== '') {
stack.unshift(`#${CSS.escape(el.id)}`)
// Remove this `break` if you want the entire path
break
} else if (sibIndex > 0) {
// :nth-of-type is 1-indexed
stack.unshift(`${nodeName}:nth-of-type(${sibIndex + 1})`)
} else {
stack.unshift(nodeName)
}
el = el.parentNode
}
return stack
}
All the examples from other ответов did not work very correctly for me, I made my own, maybe my version will be more suitable for the rest
const getDomPath = element => {
let templateElement = element
, stack = []
for (;;) {
if (!!templateElement) {
let attrs = ''
for (let i = 0; i < templateElement.attributes.length; i++) {
const name = templateElement.attributes[i].name
if (name === 'class' || name === 'id') {
attrs += `[${name}="${templateElement.getAttribute(name)}"]`
}
}
stack.push(templateElement.tagName.toLowerCase() + attrs)
templateElement = templateElement.parentElement
} else {
break
}
}
return stack.reverse().slice(1).join(' > ')
}
const currentElement = document.querySelectorAll('[class="serp-item__thumb justifier__thumb"]')[7]
const path = getDomPath(currentElement)
console.log(path)
console.log(document.querySelector(path))
console.log(currentElement)
var obj = $('#show-editor-button'),
path = '';
while (typeof obj.prop('tagName') != "undefined"){
if (obj.attr('class')){
path = '.'+obj.attr('class').replace(/\s/g , ".") + path;
}
if (obj.attr('id')){
path = '#'+obj.attr('id') + path;
}
path = ' ' +obj.prop('tagName').toLowerCase() + path;
obj = obj.parent();
}
console.log(path);
hello this function solve the bug related to current element not show in the path
check this now
$j(".wrapper").click(function(event) {
selectedElement=$j(event.target);
var rightArrowParents = [];
$j(event.target).parents().not('html,body').each(function() {
var entry = this.tagName.toLowerCase();
if (this.className) {
entry += "." + this.className.replace(/ /g, '.');
}else if(this.id){
entry += "#" + this.id;
}
entry=replaceAll(entry,'..','.');
rightArrowParents.push(entry);
});
rightArrowParents.reverse();
//if(event.target.nodeName.toLowerCase()=="a" || event.target.nodeName.toLowerCase()=="h1"){
var entry = event.target.nodeName.toLowerCase();
if (event.target.className) {
entry += "." + event.target.className.replace(/ /g, '.');
}else if(event.target.id){
entry += "#" + event.target.id;
}
rightArrowParents.push(entry);
// }
where $j = jQuery Variable
also solve the issue with .. in class name
here is replace function :
function escapeRegExp(str) {
return str.replace(/([.*+?^=!:${}()|\[\]\/\\])/g, "\\$1");
}
function replaceAll(str, find, replace) {
return str.replace(new RegExp(escapeRegExp(find), 'g'), replace);
}
Thanks
$(".rightArrow")
.parents()
.map(function () {
var value = this.tagName.toLowerCase();
if (this.className) {
value += '.' + this.className.replace(' ', '.', 'g');
}
return value;
})
.get().reverse().join(", ");

JS hasAttribute with data attribute value

Is there a native way, no jQuery, to check if a dom element has the attribute with the selected value. For example:
//assume doc has
data-mod="do" defined
This will be true:
document.hasAttribute('data-mod');
but this will be false:
document.hasAttribute('data-mod="do"')
Is there any way to natively check for a data attribute on a DOM element with the value?
You have to access the attribute's value via getAttribute and compare it to your expected string:
if (node.getAttribute('data-mod') === 'do') {
...
}
For modern browsers you can use matches:
if (node.matches('[data-mod="do"]')) {
...
}
… or for [data-*] attributes you can use dataset:
if (node.dataset.mod === 'do') {
...
}
You can do it properly with dataset,
if (elementNode.dataset['mod'] == 'do') {
//your code goes here.
}
By using dataset you can access the data-attributes of an element easily.
Yes, here it goes:
var selector = document.getElementsByTagName("H1")[0]; //Exemple of a h1
if (selector.getAttribute('data-mod') == "do"){
//Do your logic
}
This may work...
var list = document.querySelectorAll('[data-mod="do"]');
You could use Element.attributes
function data(el, dataName, dataValue) {
for (var i = 0; i < el.attributes.length; i++) {
if (/^(data)(?=-\w+|=[^=]*$|=$|$)/g.test(el.attributes[i].name)) {
if (dataName && el.attributes[i].name === "data-" + dataName) {
if (dataName && dataValue
&& el.attributes[i].name === "data-" + dataName
&& el.attributes[i].value === dataValue) {
return true
}
return true
} else {
return true
}
}
}
return false
}
var elems = document.querySelectorAll("div");
for (var i = 0; i < elems.length; i++) {
console.log(data(elems[i]))
}
var _name = "prop", _value = "123";
console.log("element #"
+ elems[1].id
+" has `data-*` attribute name:"
+_name
+", value:"+_value
, data(elems[1], _name, _value))
<div data="abc">abc</div>
<div id="prop" data-prop="123">123</div>
<div>no data</div>

Does an Inverse querySelector exist?

I know I can can use querySelector to locate an element in a document
var element = document.querySelector(".myclass")
but does there exist a inverse querySelector such that:
var selector = document.inverseQuerySelector(element);
Assert.AreEqual(element, document.querySelector(selector));
the returned selector of inverseQuerySelector always uniquely identifies the specified element?
You can create one that can work in all cases. In two ways:
Using nth-child ( which is using index)
The solution is the following:
function getMyPathByIndex(element){
if(element == null)
return '';
if(element.parentElement == null)
return 'html'
return getMyPathByIndex(element.parentElement) + '>' + ':nth-child(' + getMyIndex(element) + ')';
}
function getMyIndex(element){
if(element == null)
return -1;
if(element.parentElement == null)
return 0;
let parent = element.parentElement;
for(var index = 0; index < parent.childElementCount; index++)
if(parent.children[index] == element)
return index + 1;
}
For instance, the element:
<a id="y" class="vote-up-off" title="This answer is useful">up vote</a>
You can get this element in this page just by typing in the console:
document.querySelector('a[title="This answer is useful"]');
has it unique querySelector:
html>:nth-child(2)>:nth-child(5)>:nth-child(1)>:nth-child(1)>:nth-child(3)>:nth-child(2)>:nth-child(6)>:nth-child(1)>:nth-child(1)>:nth-child(1)>:nth-child(1)>:nth-child(1)>:nth-child(2)
Using attributes for a "human readable" way:
Get the attributes of the elements ( only the explicit attributes).
Get the entire path to the element.
Use the multiple attribute selector to unify all the features.
Using the same elemen before has it unique querySelector:
html>body>div>div>div>div>div>div>table>tbody>tr>td>div>a[id="y"][class="vote-up-off"][title="This
answer is useful"]
test if the solution is the correct by:
// e is an element and e must exist inside the page
document.querySelector( getMyPathByIndex(e)) === e &&
document.querySelectorAll( getMyPathByIndex(e)).length === 1
The code solutions is the follow:
function convertAttributesToQuerySelector(element){
var tagName = element.tagName.toLowerCase();
var result = tagName;
Array.prototype.slice.call(element.attributes).forEach( function(item) {
if(element.outerHTML.contains(item.name))
result += '[' + item.name +'="' + item.value + '"]';
});
return result;
//["a[id="y"]", "a[class="vote-up-off"]", "a[title="This answer is useful"]"]
}
function getMyPath(element){
if(element.parentElement.tagName == 'HTML')
return 'html';
return getMyPath(element.parentElement) + '>' + element.parentElement.tagName.toLowerCase() ;
//"html>body>div>div>div>div>div>div>table>tbody>tr>td>div"
}
function myUniqueQuerySelector(element){
var elementPath = getMyPath(element);
var simpleSelector = convertAttributesToQuerySelector(element);
return elementPath + '>' + simpleSelector;
}
You can always test if the solution is the correct by:
// e is an element and e must exist inside the page
document.querySelector( myUniqueQuerySelector(e)) === e &&
document.querySelectorAll( myUniqueQuerySelector(e)).length === 1
No, because there are many selectors (probably infinite) that can select the same element.
For a function to be inversable (even in math), it's mapping has to be 1 to 1, this is not the case.
BTW, Because of that, you could create some that may work only in some cases. For example:
function inverseForElementWithUniqueId(element){
return '#' + element.id;
}
var selector = inverseForElementWithUniqueId(element);
Assert.AreEqual(element, document.querySelector(selector)); //True
(code which indeed may look trivial)
But as said, because of the theory, this would work only in a subset of the cases.
But, it would work only sometimes
I mixed the 2 solutions proposed to have a result readable by humans and which gives the right element if there are several similar siblings:
function elemToSelector(elem) {
const {
tagName,
id,
className,
parentNode
} = elem;
if (tagName === 'HTML') return 'HTML';
let str = tagName;
str += (id !== '') ? `#${id}` : '';
if (className) {
const classes = className.split(/\s/);
for (let i = 0; i < classes.length; i++) {
str += `.${classes[i]}`;
}
}
let childIndex = 1;
for (let e = elem; e.previousElementSibling; e = e.previousElementSibling) {
childIndex += 1;
}
str += `:nth-child(${childIndex})`;
return `${elemToSelector(parentNode)} > ${str}`;
}
Test with:
// Select an element in Elements tab of your navigator Devtools, or replace $0
document.querySelector(elemToSelector($0)) === $0 &&
document.querySelectorAll(elemToSelector($0)).length === 1
Which might give you something like, it's a bit longer but it's readable and it always works:
HTML > BODY:nth-child(2) > DIV.container:nth-child(2) > DIV.row:nth-child(2) > DIV.col-md-4:nth-child(2) > DIV.sidebar:nth-child(1) > DIV.sidebar-wrapper:nth-child(2) > DIV.my-4:nth-child(1) > H4:nth-child(3)
Edit: I just found the package unique-selector
you can use this :
const querySelectorInvers = (elem) => {
let query = "";
document.querySelectorAll('*').forEach((el) => {
if (el !== elem) {
query += ":not(" + el.tagName + ")";
}
});
return query;
}

add class with JavaScript

I am writing some vanilla JavaScript to create a nice navigation menu. I am stuck on adding an active class.
I am getting elements by class name NOT by id. The below code works if substituted with id, however, I need it to apply to more than one element.
HTML
<img class="navButton" id="topArrow" src="images/arrows/top.png" />
<img class="navButton" id="rightArrow" src="images/arrows/right.png" />
JS
var button = document.getElementsByClassName("navButton");
button.onmouseover = function() {
button.setAttribute("class", "active");
button.setAttribute("src", "images/arrows/top_o.png");
}
No answers containing jQuery please.
document.getElementsByClassName returns a node list. So you'll have to iterate over the list and bind the event to individual elements. Like this...
var buttons = document.getElementsByClassName("navButton");
for(var i = 0; i < buttons.length; ++i){
buttons[i].onmouseover = function() {
this.setAttribute("class", "active");
this.setAttribute("src", "images/arrows/top_o.png");
}
}
In your snippet, button is an instance of NodeList, to which you can't attach an event listener directly, nor can you change the elements' className properties directly.
Your best bet is to delegate the event:
document.body.addEventListener('mouseover',function(e)
{
e = e || window.event;
var target = e.target || e.srcElement;
if (target.tagName.toLowerCase() === 'img' && target.className.match(/\bnavButton\b/))
{
target.className += ' active';//set class
}
},false);
Of course, my guess is that the active class needs to be removed once the mouseout event fires, you might consider using a second delegator for that, but you could just aswell attach an event handler to the one element that has the active class:
document.body.addEventListener('mouseover',function(e)
{
e = e || window.event;
var oldSrc, target = e.target || e.srcElement;
if (target.tagName.toLowerCase() === 'img' && target.className.match(/\bnavButton\b/))
{
target.className += ' active';//set class
oldSrc = target.getAttribute('src');
target.setAttribute('src', 'images/arrows/top_o.png');
target.onmouseout = function()
{
target.onmouseout = null;//remove this event handler, we don't need it anymore
target.className = target.className.replace(/\bactive\b/,'').trim();
target.setAttribute('src', oldSrc);
};
}
},false);
There is some room for improvements, with this code, but I'm not going to have all the fun here ;-).
Check the fiddle here
Here is a method adapted from Jquery 2.1.1 that take a dom element instead of a jquery object (so jquery is not needed). Includes type checks and regex expressions:
function addClass(element, value) {
// Regex terms
var rclass = /[\t\r\n\f]/g,
rnotwhite = (/\S+/g);
var classes,
cur,
curClass,
finalValue,
proceed = typeof value === "string" && value;
if (!proceed) return element;
classes = (value || "").match(rnotwhite) || [];
cur = element.nodeType === 1
&& (element.className
? (" " + element.className + " ").replace(rclass, " ")
: " "
);
if (!cur) return element;
var j = 0;
while ((curClass = classes[j++])) {
if (cur.indexOf(" " + curClass + " ") < 0) {
cur += curClass + " ";
}
}
// only assign if different to avoid unneeded rendering.
finalValue = cur.trim();
if (element.className !== finalValue) {
element.className = finalValue;
}
return element;
};
getElementsByClassName() returns HTMLCollection so you could try this
var button = document.getElementsByClassName("navButton")[0];
Edit
var buttons = document.getElementsByClassName("navButton");
for(i=0;buttons.length;i++){
buttons[i].onmouseover = function(){
this.className += ' active' //add class
this.setAttribute("src", "images/arrows/top_o.png");
}
}
There is build in forEach loop for array in ECMAScript 5th Edition.
var buttons = document.getElementsByClassName("navButton");
Array.prototype.forEach.call(buttons,function(button) {
button.setAttribute("class", "active");
button.setAttribute("src", "images/arrows/top_o.png");
});
I like to use a custom "foreach" function of sorts for these kinds of things:
function Each( objs, func )
{
if ( objs.length ) for ( var i = 0, ol = objs.length, v = objs[ 0 ]; i < ol && func( v, i ) !== false; v = objs[ ++i ] );
else for ( var p in objs ) if ( func( objs[ p ], p ) === false ) break;
}
(Can't remember where I found the above function, but it has been quite useful.)
Then after fetching your objects (to elements in this example) just do
Each( elements, function( element )
{
element.addEventListener( "mouseover", function()
{
element.classList.add( "active" );
//element.setAttribute( "class", "active" );
element.setAttribute( "src", "newsource" );
});
// Remove class and new src after "mouseover" ends, if you wish.
element.addEventListener( "mouseout", function()
{
element.classList.remove( "active" );
element.setAttribute( "src", "originalsource" );
});
});
classList is a simple way for handling elements' classes. Just needs a shim for a few browsers. If you must use setAttribute you must remember that whatever is set with it will overwrite the previous values.
EDIT: Forgot to mention that you need to use attachEvent instead of addEventListener on some IE versions. Test with if ( document.addEventListener ) {...}.
Simply add a class name to the beginning of the funciton and the 2nd and 3rd arguments are optional and the magic is done for you!
function getElementsByClass(searchClass, node, tag) {
var classElements = new Array();
if (node == null)
node = document;
if (tag == null)
tag = '*';
var els = node.getElementsByTagName(tag);
var elsLen = els.length;
var pattern = new RegExp('(^|\\\\s)' + searchClass + '(\\\\s|$)');
for (i = 0, j = 0; i < elsLen; i++) {
if (pattern.test(els[i].className)) {
classElements[j] = els[i];
j++;
}
}
return classElements;
}

Highlight Text in textarea when a Hashtag typed followed by one or more character

I want to be able to let the user wile typing in the text area if he typed a hash-tag followed by one or more character as he type the text get highlighted till he hits space.
The thing is i want to achieve something like Facebook's new hash-tag feature, I've done the logic the coding but still not able to achieve it visually.
The approach i tried is by using Jquery as follows:
<textarea id="txtArea">Here is my #Hash</textarea>
$("#txtArea").onkeyup(function(){
var result = $("#txtArea").match(/ #[\w]+/g);
//result = '#Hash'
});
But i couldn't complete & i don't know where to go from here so any solution, advice, plugin that i could use i'll be very grateful.
I don't believe there is any way to highlight words (other than one single highlight) within a basic textarea as it does not accept markup, you could turn the textarea into a small Rich Text editor, but that seems a little overcomplicated. I would probably go for similar approach to the editor here on SO, and have a preview window below so that you can see what is being marked. You could use something like this, of course you may want to change how it works a little to suit your exact needs. It should at least give you some ideas.
CSS
#preview {
height: 2em;
width: 12em;
border-style: solid;
border-width: 1px;
}
.hashSymbol {
color: #f90;
}
HTML
<textarea id="userInput"></textarea>
<div id="preview"></div>
Javascript
/*jslint maxerr: 50, indent: 4, browser: true */
(function () {
"use strict";
function walkTheDOM(node, func) {
func(node);
node = node.firstChild;
while (node) {
walkTheDOM(node, func);
node = node.nextSibling;
}
}
function getTextNodes(element) {
var nodes = [];
walkTheDOM(element, function (node) {
if (node.nodeType === 3) {
nodes.push(node);
}
});
return nodes;
}
function escapeRegex(string) {
return string.replace(/[\[\](){}?*+\^$\\.|]/g, "\\$&");
}
function highlight(element, string, classname) {
var nodes = getTextNodes(element),
length = nodes.length,
stringLength = string.length,
rx = new RegExp("\\B" + escapeRegex(string)),
i = 0,
index,
text,
newContent,
span,
node;
while (i < length) {
node = nodes[i];
newContent = document.createDocumentFragment();
text = node.nodeValue;
index = text.search(rx);
while (index !== -1) {
newContent.appendChild(document.createTextNode(text.slice(0, index)));
text = text.slice(index + stringLength);
span = document.createElement("span");
span.className = classname;
span.appendChild(document.createTextNode(string));
newContent.appendChild(span);
index = text.search(rx);
}
newContent.appendChild(document.createTextNode(text));
node.parentNode.replaceChild(newContent, node);
i += 1;
}
}
function addEvent(elem, event, fn) {
if (typeof elem === "string") {
elem = document.getElementById(elem);
}
function listenHandler(e) {
var ret = fn.apply(null, arguments);
if (ret === false) {
e.stopPropagation();
e.preventDefault();
}
return ret;
}
function attachHandler() {
window.event.target = window.event.srcElement;
var ret = fn.call(elem, window.event);
if (ret === false) {
window.event.returnValue = false;
window.event.cancelBubble = true;
}
return ret;
}
if (elem.addEventListener) {
elem.addEventListener(event, listenHandler, false);
} else {
elem.attachEvent("on" + event, attachHandler);
}
}
function emptyNode(node) {
while (node.firstChild) {
node.removeChild(node.firstChild);
}
}
function toPreviewHighlight(e, to) {
if (typeof to === "string") {
to = document.getElementById(to);
}
var value = e.target.value,
tags = value.match(/\B#\w+/g) || [],
index = tags.length - 1,
lookup = {},
fragment,
length,
tag;
while (index >= 0) {
tag = tags[index];
if (!tag.length || tag === "#" || tag.charAt(0) !== "#" || lookup[tag]) {
tags.splice(index, 1);
} else {
lookup[tag] = true;
}
index -= 1;
}
fragment = document.createDocumentFragment();
fragment.appendChild(document.createTextNode(value));
index = 0;
length = tags.length;
while (index < length) {
tag = tags[index];
highlight(fragment, tag, "hashSymbol");
index += 1;
}
emptyNode(to);
to.appendChild(fragment);
}
addEvent("userInput", "keyup", function (e) {
toPreviewHighlight(e, "preview");
});
}());
On jsfiddle
This code is slightly modified from other questions and answers here on SO (resusing code is good)
if text contains '#' change color of '#'
How to extract value between # and space in textarea value
Using JavaScript, I want to use XPath to look for the presence of a string, then refresh the page based on that

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