In css I have set all the <hr> elements in my html to "display:none;" which works.
I have an onclick event listener set up to change the "display" to "block".
I use:
document.getElementsByTagName("hr").innerHTML.style.display = "block";
I get an error "Cannot read property 'style' of undefined".
Do it the following way:
var hrItems = document.getElementsByTagName("hr");
for(var i = 0; i < hrItems.length; i++) {
hrItems[i].style.display = 'block';
}
This is incorrect in two ways
getElementsByTagName gives you a list on elements and there is no method to operate on all elements, so you'll have to loop through all of them and add the required style individually.
innerHTML returns a string containing the mark up in an element but <hr> doesn't have any thing in it and the style property is on the <hr> itself.
var hrs = document.getElementsByTagName("hr");
for(var i = 0; i < hrs.length; i++) {
hrs[i].style.display = 'block';
}
Simple (and very effective) solution:
tag your body with a class-element
<body class="no_hr"> <article><hr/> TEXT Foo</article> <hr/> </body>
in css don't hide hr directly, but do
.no_hr hr {
display:none;
}
now define a second style in your css
.block_hr hr{
display:block;
}
in your buttons onClick, change the one and only body class from no_hr to block_hr
onclick() {
if ( document.body.className == "no_hr" ) {
document.body.className = "block_hr";
} else {
document.body.className = "no_hr";
}
}
This is a very charming solution, because you don't have to iterate over elements yourself, but let your browsers optimized procedures do their job.
For people who want a solution that doesn't require JavaScript.
Create an invisible checkbox at the top of the document and make sure that people can click on it.
<input type="checkbox" id="ruler"/>
<label for="ruler">Click to show or hide the rules</label>
Then tell the stylesheet that the <hr>s should be hidden by default, but should be visible if the checkbox is checked.
#ruler, hr {display:none}
#ruler:checked ~ hr {display:block}
Done. See fiddle.
getElementsByTagName() returns a node list, and therefore you must iterate through all the results. Additionally, there is no innerHTML property of an <hr> tag, and the style must be set directly on the tag.
I like writing these types of iterations using Array.forEach() and call:
[].forEach.call(document.getElementsByTagName("hr"), function(item) {
item.style.display = "block";
});
Or, make it even easier on yourself and use jQuery:
$("hr").show();
Related
I would like to change the styling attribute values of all elements that have the class "post-feature" and contain an attribute value of "http"
So the div element will look like the following:
<div class="post-feature" style="backgroundimage:url(http://local.test.com/test_image.jpg);">
So far the http check works. But I am not able to set the attribute value.
I have the following code
var features = document.getElementsByClassName(".post-feature")
[0].getAttribute("style");
if (features.includes("http")) {
features.setAttribute("background-color", "orange");
} else {
alert('no change');
}
You can use querySelectorAll('.post-feature[style*="http"]') to find those elements.
Then simply iterate through them and i.e. set their background color with
element.style.backgroundColor = 'orange';
Now, if you want to make sure you only target elements having a background-image and http, you can use this selector:
querySelectorAll('.post-feature[style*="http"][style*="background-image"]')
Also, by adding an i (or I) just before the end bracket [style*="http"i], the value will be compared case-insensitively.
window.addEventListener('load', function() {
var elements = document.querySelectorAll('.post-feature[style*="http"]');
for (var i = 0; i < elements.length; i++) {
elements[i].style.backgroundColor = 'orange'; /* add propert value */
/* replace class
elements[i].className = 'myClass';
*/
/* add a class
elements[i].classList.add('myClass');
*/
}
/* temp log */
console.log('Found ', elements.length,' element(s)');
})
div {
height: 40px;
background-color: gray;
}
div + div {
margin-top: 10px;
}
<div class="post-feature" style="background-image:url(http://local.test.com/test_image.jpg);"></div>
<div class="post-feature"></div>
<div class="post-feature" style="background-image:url(http://local.test.com/test_image.jpg);"></div>
<div class="post-feature"></div>
Updated
To only change styling, like colors etc., you don't even need a script, you can use CSS alone
div {
height: 40px;
background-color: gray;
}
div + div {
margin-top: 10px;
}
/* for elements that contain "http" and "background-image" */
.post-feature[style*="http"i][style*="background-image"i] {
background-color: orange;
}
<div class="post-feature" style="background-image:url(http://local.test.com/test_image.jpg);"></div>
<div class="post-feature"></div>
<div class="post-feature" style="background-image:url(HTTP://local.test.com/test_image.jpg);"></div>
<div class="post-feature"></div>
As a note, and as discussed in a few comments, if to make sure it is the background-image property that also contain the http in its url(), you can adjust the selector to this, which as well can be used without any script, as a CSS rule
.post-feature[style*="background-image:url(http"i] {
background-color: orange;
}
The above selector can of course also be used in the first sample, like this
querySelectorAll('.post-feature[style*="background-image:url(http"i]')
First, you can use querySelctorAll() with a CSS query that selects the elements with the class you desire and, in most cases, you should use this instead of getElementsByClassName() as that returns a "live node list" that causes the DOM to be re-scanned every time you access it.
Next, setAttribute() is for setting HTML element attributes. You are asking to change the value of a CSS property. While that could be accomplished with setAttribute('style', value), it is very "old-school" and not the best approach, nor is getAttribute('style') the best way to read a CSS property value (it won't work if the CSS was set from a style sheet).
Also, your code is trying to access: backgroundimage, but the property is accessed as background-image when working in CSS and backgroundImage when accessing it via JavaScript.
To access the inline styles applied to an HTML element, just access the style property of that element, followed by the name of the CSS property you are interested in. For example:
var bColor = element.style.backgroundColor;
If the style has been applied to the element from an internal style sheet or an external style sheet, the above approach won't work for you and you'll need to get it another way, via window.getComputedStyle():
var bColor = window.getComputedStyle(element, null).backgroundColor;
But, note that getComputedStyle() doesn't always return the same value that you set - - it's the value after the browser has computed all factors. In this case, even paths that you wrote as relative references (without the "http") will be returned as absolute paths (with the http).
So, here is a modern approach that correctly checks only the background-image CSS property for the presence of http.
NOTE: This solution tests for http specifically in the background-image property. Unlike most of the other answers given, this code will correctly ignore http in other CSS properties besides background-image. Examine the CSS of the last div to see this in action.
// querySelectorAll() is more efficient than getElementsByClassName()
var features = document.querySelectorAll(".post-feature");
// Loop over the list
for(var i = 0; i < features.length; i++){
// Get access to the background-image property (called backgroundImage from JavaScript) value,
// convert that value to lower case and check to see if "http" is in that value
if(features[i].style.backgroundImage.toLowerCase().indexOf("http") > -1){
// Set the CSS background-color property (called "backgroundColor" in JavaScript) to orange:
features[i].style.backgroundColor = "orange";
// Just for testing:
features[i].textContent = features[i].style.backgroundImage;
} else {
alert("No change");
}
}
.post-feature { width:100%; height:50px; border:1px solid black; background-color:gray; color:yellow; }
<!-- The correct CSS property is "background-image", not "backgroundimage" -->
<div class="post-feature" style="background-image:url(http://local.test.com/test_image.jpg);"></div>
<div class="post-feature" style="background-image:url(test_image.jpg);"></div>
<div class="post-feature" style="background-image:url(http://local.test.com/test_image.jpg);"></div>
<div class="post-feature"
style="border-image: url('http:///images/border.png') 30 30 repeat;background-image:url(test_image.jpg);">I have "http" in one of my CSS properties, but not "background-image", so I shouldn't be orange.</div>
i think some wrong in your code, try this code
element.setAttribute("style", "background-color: orange;"); // bad
or
element.style.backgroundColor = "orange"; // good
Use element.style.backgroundColor and indexOf
var features = document.getElementsByClassName(".post-feature")[0].getAttribute("style");
if (features.indexOf("http") > -1) {
features.style.backgroundColor = "orange";
} else {
alert('no change');
}
check this fiddle
https://jsfiddle.net/vywk72j8/2/
<div class="post-feature" style="background-image:url(http://local.test.com/test_image.jpg);">
tt</div>
var feature = document.getElementsByClassName("post-feature")[0];
if (feature.style.backgroundImage.indexOf("http") !== -1) {
feature.style.backgroundColor = "orange";
} else {
alert('no change');
}
In your code, you are fetching the attribute value in features
var features = document.getElementsByClassName(".post-feature")
[0].getAttribute("style");
Here features is a string containing attribute value, not an element so you cannot use it to set value.
I'd like to remove the ugly focus outline on an input button in firefox. I've tried adding ::-moz-focus-inner {border:0;} as style in my html, which works initially, but not when button elements are re-created via javascript.
I've tried:
cell.style.mozFocusInner.border = "0";
cell.style["-moz-focus-inner"] = "{border:0}";
cell.style["-moz-focus-inner"]["border"] = "0";
etc.
In general, how do I "map" css to javascript?
According to the CSS property to IDL attribute algorithm, a -moz-focus-inner would be camelCased to MozFocusInner. So you could use one of
element.style.MozFocusInner = value;
element.style.setPropertyValue('-moz-focus-inner', value);
element.style.setProperty('-moz-focus-inner', value);
element.style.setProperty('-moz-focus-inner', value, '!important');
But there is a big problem: -moz-focus-inner is not a CSS property, is a pseudo-element.
Given an element, you can read the computed styles of its pseudo-elements via getComputedStyle:
getComputedStyle(element, '::-moz-focus-inner').borderTopWidth; // 1px
However, you can't set them directly. If you want to do that, you can:
Conditionally set the desired styles in a stylesheet, and use JS to trigger that condition whenever you want. For example, add a class.
document.getElementById('enable').addEventListener('click', function() {
document.getElementById('target').classList.remove('no-focus-inner');
});
document.getElementById('disable').addEventListener('click', function() {
document.getElementById('target').classList.add('no-focus-inner');
});
.no-focus-inner::-moz-focus-inner {
border: none;
}
<ol>
<li><button id="enable">Enable inner outline</button> or <button id="disable">Disable inner outline</button></li>
<li>Press Tab key</li>
<li><button id="target">Focus me to check if I have inner outline</button></li>
</ol>
Create a new stylesheet with the desired rulesets, and append it to the document.
var styleSheet = document.createElement('style');
styleSheet.textContent = '#target::-moz-focus-inner { border: none; }';
document.getElementById('enable').addEventListener('click', function() {
if(styleSheet.parentNode) document.head.removeChild(styleSheet);
});
document.getElementById('disable').addEventListener('click', function() {
document.head.appendChild(styleSheet);
});
<ol>
<li><button id="enable">Enable inner outline</button> or <button id="disable">Disable inner outline</button></li>
<li>Press Tab key</li>
<li><button id="target">Focus me to check if I have inner outline</button></li>
</ol>
Maybe this works without javascript: https://css-tricks.com/forums/topic/button-padding-issue/
::moz-focus-inner is a pseudo-element. In this link are several ways how to modify pseudo-elements dynamically (with javascript) http://pankajparashar.com/posts/modify-pseudo-elements-css/
cited from http://pankajparashar.com/posts/modify-pseudo-elements-css/ :
<p class="red">Hi, this is a plain-old, sad-looking paragraph tag.</p>
.red::before {
content: 'red';
color: red;
}
Method 1
Write separate classes attached with pseudo element for each style and then using JavaScript or jQuery toggle between these classes.
.green::before {
content: 'green';
color: green;
}
$('p').removeClass('red').addClass('green');
...
Common css-styles (not pseudo-elements) can be modified using javascript like this:
cited from https://www.kirupa.com/html5/setting_css_styles_using_javascript.htm :
Every HTML element that you access via JavaScript has a style object. This object allows you to specify a CSS property and set its value. For example, this is what setting the background color of an HTML element whose id value is superman looks like:
var myElement = document.querySelector("#superman");
myElement.style.backgroundColor = "#D93600";
To affect many elements, you can do something as follows:
var myElements = document.querySelectorAll(".bar");
for (var i = 0; i < myElements.length; i++) {
myElements[i].style.opacity = 0;
}
In a nutshell, to style elements directly using JavaScript, the first step is to access the element. I am using the querySelector method to make that happen. The second step is just to find the CSS property you care about and give it a value. Remember, many values in CSS are actually strings. Also remember that many values require a unit of measurement like px or em or something like that to actually get recognized.
I need to hide all the elements that have the string "replies-36965584" anywhere in their IDs.
HTML:
<div id="replies-36965584_1">aaaa</div>
<div id="replies-36965584_2">aaaa</div>
<div id="replies-36965584_3">aaaa</div>
<div id="replies-36965584_4">aaaa</div>
<div id="replies-36222224_2">nnnn</div>
JavaScript:
document.getElementById("replies-36965584").style.display="none"
How can I modify this JS to select the first four elements?
You can do this with CSS and attribute selectors.
[att^=val]
Represents an element with the att attribute whose value begins with the prefix "val". If "val" is the empty string then the selector does not represent anything.
Source: http://www.w3.org/TR/css3-selectors/#attribute-substrings
jsfiddle
CSS
[id^="replies-36965584_"] {
display: none;
}
Is using jQuery an option? If so, this is dead simple:
$(document).ready(function(){
$('div[id^="replies-36965584"]').hide();
});
If you're unfamiliar with jQuery, here's a link to get started: http://learn.jquery.com/javascript-101/getting-started/
EDIT: Fixed syntax error.
EDIT: Added jsFiddle: http://jsfiddle.net/xbVp9/
If you don't know certain literal values but you know the general pattern and only the number will change, then I will consider some matching with regular expresiion.
You can do it the painful way:
var o = document.getElementsByTagName("div");
for (var i=0;i<o.length;i++) {
if(o[i].id.indexOf('replies-36965584') == 0) {
o[i].style.display = 'none';
}
}
The only way to do this with vanilla javascript that I know of, is to fetch all the divs on the page, and test the id's for the ones you want.
var divs = document.getElementsByTagName('div');
for (var i = 0; i < divs.length; ++i) {
var div = divs[i];
if (/replies-36965584/.test(div.id)) {
div.style.display = 'none';
}
}
How do I change the CSS property display, in JavaScript, from display:none to display:normal for these divs?
#hide_0 { display:none }
#hide_1 { display:none }
#hide_2 { display:none }
#hide_3 { display:none }
#hide_4 { display:none }
#hide_5 { display:none }
Only one at a time. I need to display one and hide the rest.
What I used:
var persistent_element='hide_1';
function link_update(link_display)
{
var local_element;
local_element=document.getElementById(persistent_element);
local_element.style.display='none';
local_element=document.getElementById(link_display);
local_element.style.display='block';
persistent_element=link_display;
}
How I connected it : m4 is a minified - connects onclick to these methods
m4('l1',function {return link_update(hide_1);});
m4('l2',function {return link_update(hide_2);});
m4('l3',function {return link_update(hide_3);});
m4('l4',function {return link_update(hide_4);});
m4('l5',function {return link_update(hide_5);});
m4('l6',function {return link_update(hide_6);});
To use javascript to change the style, you can do it like this:
// hide an element
document.getElementById("hide_0").style.display = "none";
// show a block element
document.getElementById("hide_1").style.display = "block";
// to go back to the default or CSS specified value
document.getElementById("hide_2").style.display = "";
So, if you wanted to hide all and show one, you could do that with this function:
function showOneHideOthers(base, len, numToShow) {
// objects must have ids like base_0, base_1, etc...
for (var i = 0; i < len; i++) {
if (i != numToShow) {
document.getElementById(base+i).style.display = "none";
}
}
document.getElementById(base+numToShow).style.display = "block";
}
showOneHideOther("hide_", 6, 2);
P.S. normal is not a valid value for the display property. The typical values are block, none and inline and there are others like inline-block, table, etc....
Your question is not particularly clear, but the essence of what you want to do is simple. You can get a reference to a DOM element which has an id using getElementById, and you can change the display property:
document.getElementById("hide_0").style.display = "none"; //or "block"
However, you have several element that you want to hide/show (I'm not sure when you want to do so), so it may be easier to use a different method of selecting the elements (such as getElementsByTagName, or getElementsByClassName, but it depends on your HTML and what you're actually trying to do).
You can set a css property on an element using the style method.
div.style.display = '';
Please refer to the following codes :
<div id="message-1" onclick="javascript:showresponddiv(this.id)>
</div>
<div id="respond-1" style="display:none;">
</div>
<div id="message-2" onclick="javascript:showresponddiv(this.id)>
</div>
<div id="respond-2" style="display:none;">
</div>
<script type="text/javascript">
function showresponddiv(messagedivid){
var responddivid = messagedivid.replace("message-", "respond-");
if (document.getElementById(responddivid).style.display=="none"){
document.getElementById(responddivid).style.display="inline";
} else {
document.getElementById(responddivid).style.display="none";
}
}
</script>
The codes above already success make the respond div appear when user click on message div. The respond div will disappear when user click on message div again. Now my question is how to make the respond div of 1st message disappear when user click on 2nd message to display the respond div of 2nd message?
You should give the "respond" divs a common class:
<div id="respond-1" class="response' style="display:none;"></div>
Then you can get all divs by using getElementsByTagName, compare the class and hide them on a match:
function hideAllResponses() {
var divs = document.getElementsByTagName('div');
for(var i = divs.length; i-- ;) {
var div = divs[i];
if(div.className === 'response') {
div.style.display = 'none';
}
}
}
We cannot use getElementsByClassName, because this method is not supported by IE8 and below. But of course this method can be extended to make use of it if it is supported (same for querySelectorAll). This is left as an exercise for the reader.
Further notes:
Adding javascript: to the click handler is syntactically not wrong but totally unnecessary. Just do:
onclick="showresponddiv(this.id)"
If you have to do a lot of DOM manipulation of this kind, you should have a look at a library such as jQuery which greatly simplify such tasks.
Update: If always only one response is shown and you are worried about speed, then store a reference to opened one:
var current = null;
function showresponddiv(messagedivid){
var id = messagedivid.replace("message-", "respond-"),
div = document.getElementById(id);
// hide previous one
if(current && current !== div) {
current.style.display = 'none';
}
if (div.style.display=="none"){
div.style.display="inline";
current = div;
}
else {
div.style.display="none";
}
}
Edit: Fixed logic. See a DEMO.
You can add some class to all divs with id="respond-"
e.g
<div id="respond-1" class="classname" style="display:none;"></div>
<div id="respond-2" class="classname" style="display:none;"></div>
Now at first row of your function "showresponddiv()" you should find all divs with class "classname" and hide them.
With jQuery it is simple code:
$(".classname").hide();
jQuery - is a Javascript Library that helps you to easy manipulate with DOM and provides cross-browser compatibility.
Also you can look to Sizzle - it is a JavaScript CSS selector engine used by jQuery for selecting DOM elements