I am completely a beginner in java script. As i know, by using this line of code:
document.getElementById('ID').value
It looks in the entire PHP file to find the value of that id (it's a text input). Is there any alternative for the documents on that line of code that let me to search only in a class?
for example i have a class called number, so :
this.block = $("#number");
can i use something like that:
this.block.getElementById('ID').value;
Or there is any another line of code that give me the value of a text input? Thanks a lot
You can use
$("#number").find("#id")
to search descendants of #number.
But if your class is number you should use $(".number") instead since that is the class selector.
I have 2 diferent divs: [Div1] and [Div2].
My goal is that when i click on some event, i want [Div1] to be the exactly the same as the [Div2].
I used this code:
document.getElementById("div1")=document.getElementById("div2");
This is a javascript error and i dont know how to do anything like this.
I cant copy every element cuz those might change based on the users actions.
I found something about cloning a node but i couldn't put it to work.
Any sugestions?
Well depending on what you mean by "exactly the same" (sharing the same reference? duplication of values?), you might want to try cloning:
Try:
var node = document.getElementById("div2");
var node2 = node.cloneNode(true); //creates deep clone with events you can do something with
///Or you could just copy the markup over
document.getElementById("div1").innerHTML = node2.innerHTML;
Use jquery instead; when the user clicks the button/any action, use the following snippet:
$("div1").html($("div2").html());
I can't seem to figure out how to clear the text from a razor Textbox.
I've tried this:
#Html.TextBoxFor(m => m.Field)
$(document).ready(function () {
$(".link").click(function () {
$("#Field").value = "";
return false;
});
});
Didn't work.
The correct way to SET the value with jQuery is to use val and pass it a value. So to clear it, use this:
$("#Field").val("")
Look at the jQuery API for val:
http://api.jquery.com/val/
If you wanted to use basic Javascript, you use .value = "", but since you are selecting an element with jQuery, you must use jQuery methods, like val.
You have several options though. This is similarly very easy with basic Javascript:
document.getElementById("Field").value = "";
If you still wanted to use jQuery but use value, you need to get the DOM element, like:
$("#Field")[0].value = "";
// or
$("#Field").get(0).value = "";
If you are using jQuery, you might as well stick with val(). The nice thing with this is that calling .val("") will not bomb the program if the element isn't found. If you use any of the other methods I mentioned, they will bomb if the element doesn't exist. So it's up to you what you really want. You can always check to see if $("#Field").length is greater than 0 before using get(0) or [0], but that's kind of overkill.
Another possible problem is that the id of the element may not be "Field". I forget what MVC does to generate the actual HTML, but it's up to you to use something like Firebug or Developer Tools to investigate and see what the id actually is. Then, you may have to replace it for "Field".
So, I have some code that should do four things:
remove the ".mp4" extension from every title
change my video category
put the same description in all of the videos
put the same keywords in all of the videos
Note: All of this would be done on the YouTube upload page. I'm using Greasemonkey in Mozilla Firefox.
I wrote this, but my question is: how do I change the HTML title in the actual HTML page to the new title (which is a Javascript variable)?
This is my code:
function remove_mp4()
{
var title = document.getElementsByName("title").value;
var new_title = title.replace(title.match(".mp4"), "");
}
function add_description()
{
var description = document.getElementsByName("description").value;
var new_description = "Subscribe."
}
function add_keywords()
{
var keywords = document.getElementsByName("keywords").value;
var new_keywords = prompt("Enter keywords.", "");
}
function change_category()
{
var category = document.getElementsByName("category").value;
var new_category = "<option value="27">Education</option>"
}
remove_mp4();
add_description();
add_keywords();
change_category();
Note: If you see any mistakes in the JavaScript code, please let me know.
Note 2: If you wonder why I stored the current HTML values in variables, that's because I think I will have to use them in order to replace HTML values (I may be wrong).
A lot of things have been covered already, but still i would like to remind you that if you are looking for cross browser compatibility innerHTML won't be enough, as you may need innerText too or textContent to tackle some old versions of IE or even using some other way to modify the content of an element.
As a side note innerHTML is considered from a great majority of people as deprecated though some others still use it. (i'm not here to debate about is it good or not to use it but this is just a little remark for you to checkabout)
Regarding remarks, i would suggest minimizing the number of functions you create by creating some more generic versions for editing or adding purposes, eg you could do the following :
/*
* #param $affectedElements the collection of elements to be changed
* #param $attribute here means the attribute to be added to each of those elements
* #param $attributeValue the value of that attribute
*/
function add($affectedElements, $attribute, $attributeValue){
for(int i=0; i<$affectedElements.length; i++){
($affectedElements[i]).setAttribute($attribute, $attributeValue);
}
}
If you use a global function to do the work for you, not only your coce is gonna be easier to maintain but also you'll avoid fetching for elements in the DOM many many times, which will considerably make your script run faster. For example, in your previous code you fetch the DOM for a set of specific elements before you can add a value to them, in other words everytime your function is executed you'll have to go through the whole DOM to retrieve your elements, while if you just fetch your elements once then store in a var and just pass them to a function that's focusing on adding or changing only, you're clearly avoiding some repetitive tasks to be done.
Concerning the last function i think code is still incomplete, but i would suggest you use the built in methods for manipulating HTMLOption stuff, if i remember well, using plain JavaScript you'll find yourself typing this :
var category = document.getElem.... . options[put-index-here];
//JavaScript also lets you create <option> elements with the Option() constructor
Anyway, my point is that you would better use JavaScript's available methods to do the work instead of relying on innerHTML fpr anything you may need, i know innerHTML is the simplest and fastest way to get your work done, but if i can say it's like if you built a whole HTML page using and tags only instead of using various semantic tags that would help make everything clearer.
As a last point for future use, if you're interested by jQuery, this will give you a different way to manipulate your DOM through CSS selectors in a much more advanced way than plain JavaScript can do.
you can check out this link too :
replacement for innerHTML
I assume that your question is only about the title changing, and not about the rest; also, I assume you mean changing all elements in the document that have "title" as name attribute, and not the document title.
In that case, you could indeed use document.getElementsByName("title").
To handle the name="title" elements, you could do:
titleElems=document.getElementsByName("title");
for(i=0;i<titleElems.length;i++){
titleInner=titleElems[i].innerHTML;
titleElems[i].innerHTML=titleInner.replace(titleInner.match(".mp4"), "");
}
For the name="description" element, use this: (assuming there's only one name="description" element on the page, or you want the first one)
document.getElementsByName("description")[0].value="Subscribe.";
I wasn't really sure about the keywords (I haven't got a YouTube page in front of me right now), so this assumes it's a text field/area just like the description:
document.getElementsByName("keywords")[0].value=prompt("Please enter keywords:","");
Again, based on your question which just sets the .value of the category thingy:
document.getElementsByName("description")[0].value="<option value='27'>Education</option>";
At the last one, though, note that I changed the "27" into '27': you can't put double quotes inside a double-quoted string assuming they're handled just like any other character :)
Did this help a little more? :)
Sry, but your question is not quite clear. What exactly is your HTML title that you are referring to?
If it's an element that you wish to modify, use this :
element.setAttribute('title', 'new-title-here');
If you want to modify the window title (shown in the browser tab), you can do the following :
document.title = "the new title";
You've reading elements from .value property, so you should write back it too:
document.getElementsByName("title").value = new_title
If you are refering to changing text content in an element called title try using innerHTML
var title = document.getElementsByName("title").value;
document.getElementsByName("title").innerHTML = title.replace(title.match(".mp4"), "");
source: https://developer.mozilla.org/en-US/docs/DOM/element.innerHTML
The <title> element is an invisible one, it is only displayed indirectly - in the window or tab title. This means that you want to change whatever is displayed in the window/tab title and not the HTML code itself. You can do this by changing the document.title property:
function remove_mp4()
{
document.title = document.title.replace(title.match(".mp4"), "");
}
I use this code to get value from an input box:
var suggest_type = document.getElementById('ac-type').value;
Now I need to apply my js code on several other pages. I heard that it's not nice to repeat an ID on one website. So, I'm thinking to change to use class like this:
var suggest_type = document.getElementByClass('ac-type').value;
This doesn't get the value. How can I use class to get value?
You should stick with using ID's - they only have to be unique within a page.
If you must use classes, you need to use getElementsByClassName():
var elems = document.getElementsByClassName('ac-type');
var value = elems[0].value;
However this function is not well supported on older browsers, which is another good reason to stick with IDs.
Its absolutely fine to repeat ids across a website just not on a single html document.
ID's should be unique within one html page.
It's actually :
var suggest_type = document.getElementsByClassName('ac-type')[0].value;
But I agree with Jon Taylor, ID's can be the same within a website, as long they are not duplicated on the same page.
try using this:
var elements = document.getElementsByClassName('ac-type'); // this is an array containing all matched elements
Use jquery just by using -
$('.ac-type').val();
you will get value.