I'm trying to learn d3js library. Faced with the problem of the capture table's TD element by clicking. I usually use this way
window.addEventListener("load", function(){
document.getElementById("table_id").addEventListener("click",function(e){
var elem = e.target || e.srcElement;
if(elem.nodeName != "TD") return;
...
}
...
So i need to do something like that in d3js. But I don't know how to substitute .target and .srcElement methods.
What I do have
d3.select(#table_id).on('click',function(){
var elem = ???
In this i have my table. In d3.event such information click clientX=327, clientY=129. The d is undefined
Please, help me to grab TD element in var.
D3js is very flexible and you don't need to use d3.event.target every time.
As you asked, some details missed in your code:
1. Selection
There are two selection functions in d3 :
d3.select() it gets or finds specific tag or element or class or tag id, for example:
d3.select('div') returns first div or d3.select('.active') find tag have class named active. In your case you should used3.select('#table_id') you missed single quotation in select function.
The next d3 selection function is d3.selectAll() that act like d3.select() but the difference is this function select all the parameters, for example :
d3.selectAll('p') return all the p tags or all Id or classes get as parameter.
2. different between this and d
this is an argument that use to select specific tag you try to select or do some stuff on it and is more usable in selectAll function because you don't know which tag selected.
d is an object or DOM that contain all the properties and events.
So I changed your code and hope it's help you to learn d3 better.
d3.select("#table_id").on("click",function(){
var elem=d3.select(this);
if(elem.attr("name")!=="TD")
return;
});
more information here.
Related
I wanted to copy an entire row including its' siblings and contents on button click. When I click the button the element, it appears in the console but doesn't append to the page. This is my code:
It doesn't show any error messages. I've tried innerHTML/outerHTML or append() it doesn't work.
$(document).ready(function() {
$('#addSubFBtn').on('click', function() {
var itm = document.getElementById("trFb");
var wrapper = document.createElement('div');
var el = wrapper.appendChild(itm);
document.getElementById("tbFb").append(el);
console.log(el);
});
});
Seems like what you're trying to do is clone the item after you get it from your document. W3schools website explains how to accomplish this. Check out the link: https://www.w3schools.com/jsref/met_node_clonenode.asp
Once you clone the node, [appendchild] should work as intended
Not sure (as said without seeing related HTML) but i see flaw in your logic:
var itm = document.getElementById("trFb");
still exist on the document(so in the page) so you've to retrieve it before you want to add/move it to another place.
using .removeElement will return you removed element(or null if no element matche the selector) so correct script should be:
var itm=document.getElementById("trFb").parentNode.removeChild(document.getElementById("trFb"));
as shown here to remove element you've to use method on to parent element.
So you can add it to any other element existing.
For more specific use or element created in global JS variable (such an createElement not yet appended) you can see :document.createDocumentFragment(); as explained here https://developer.mozilla.org/en-US/docs/Web/API/Document/createDocumentFragment
I have this html code:
<b class = "edit" id = "foo1">FOO</b>
<b class = "edit" id = "foo2">FOO2</b>
<b class = "edit" id = "foo3">FOO3</b>
And I have this code in jQuery:
$('b.edit').click(function(){
//GET THE ID OF THE b.edit: e.g foo1, foo2, foo3
$('.editP').focus();
});
How can I get the id value of the b.edit, as there are multiple instances of b.edit, and I want to get the specific id of the one clicked? How can I do this?
Thanks, Sorry, I am pretty new to javascript.
I'm assuming from your sample code that you're using jQuery? If so you can get the id as follows:
$('b.edit').click(function(){
this.id;
});
EDIT:
The direct reference to the attribute is indeed more efficient if all that is required is simply the id.
Also can be obtained from the jQuery object:
$('b.edit').click(function(){
$(this).attr('id');
});
Sample fiddle: http://jsfiddle.net/5bQQT/
Try with this:
$('b.edit').click(function(e){ //When you use an event is better
//send the event variable to the
//binding function.
var id = e.target.id; //get the id of the clicked element.
/*do your stuff*/
$('.editP').focus();
});
try this. You can use keyword "this" to retrieve the attr ID...
$('b.edit').click(function(){
alert($(this).attr("id"));
});
$('.edit').click(function(){
var theId = $(this).attr('id');
}
This will get you the ID of anything clicked with a class of .edit
$('.edit').live('click', function() {
alert( this.id );
});
Sample
http://jsfiddle.net/ck2Xk/
When passing a click handler in JQuery, you actually have a reference to something called an event object. This event object has a property called target, which is a reference to the element that was clicked.
$('b.edit').click(function(eventObject){
eventObject.target // this is the element that was clicked.
});
Since you have a reference to the target element, you can do whatever you like. In this case, you could just access eventObject.target.id.
Since nobody has shown the simplest method yet that doesn't even need jQuery to get the id:
$('.edit').click(function() {
alert(this.id);
});
I never understand why people use jQuery for getting simple attributes which involves two jQuery function calls (and a bunch of overhead to create a jQuery object) instead of one direct attribute reference.
something like this:
var id = $(this).attr('id');
More clearly:
$('b.edit').live('click', function(){
var id = $(this).attr('id');
// in this scope this.id works too
// var id = this.id;
});
This is called event delegation in Javascript. More info can be found in Zakas blog http://www.nczonline.net/blog/2009/06/30/event-delegation-in-javascript/
The idea in few words is you attache the event to a parent node and then waiting for some event on the child node. In the example below I attach the onclick event to the document itself. Then inside the event handler you will write a switch statement to check the clicked element id, then do what you want to do for that element
document.onclick = function(event){
//IE doesn't pass in the event object
event = event || window.event;
//IE uses srcElement as the target
var target = event.target || event.srcElement;
switch(target.id){
case "foo1":
foo1();
break;
case "foo2":
foo2();
break;
case "foo3":
foo3();
break;
//others?
}
};
//some dummy handlers
var foo1 = function(){
alert("You clicked foo1");
};
var foo2 = function(){
alert("You clicked foo2");
};
var foo3 = function(){
alert("You clicked foo3");
};
For how to implement event delegation in jQuery you can check http://api.jquery.com/on/#direct-and-delegated-events
Even though this is not a real answer to your question. I will try to explain why what your asking is not the way to go. Since you are new especially, since learing bad practices could be hard to unlearn. Allways try to search for an ID before finding an element by its Class. Also try to avoid giving every element the same class (and in this case ID to), just give it an encapsulating parent.
Furthermore, the id of an element is really specific and should preferably used to find / select / bind events to. An id should usually be unique for this to work, so in your case a couple of things could be optimized, lets say like:
<div id="foo">
<b id="1">Foo</b>
<b id="2">Other foo</b>
<b id="3">Some foo</b>
</div>
Now if you want to know which was clicked there are multiple ways to accomplish it, but a nice one is simply binding a parent its children (i.e <div id="foo"> .. </div>). This way you can alter the structure of your pretty fast, without changing all the classes and id's.
With jQuery you can get the attribute id using the .attr() function. However I told you the id was pretty specific and thus has its own rights in javascript world. An id can also be directly targeted ('DOMelement.id', but this would be too much to explain for now)
In two ways the <b> can be targetted:
Example a)
var b_elements = $("#foo").children();
Example b)
var b_elements = $("#foo").find('b');
We can add jQuery (or javascript events) to these found elements. The nice thing about jQuery is that it simplifies alot of work. So in your case if you would like to know an id of a certain clicked <b> field you could use a very verbose way:
b_elements.click(function()
{
var clicked_element = $(this);
alert(clicked_element.attr('id'));
});
Verbose because you can do it much much shorter, but who cares about a few bytes when your learning and this makes remembering functions and events alot easier. Say you wanted to get the class edit by finding the where you knew the id that was clicked:
b_elements.click(function()
{
var clicked_element = $(this);
alert(clicked_element.attr('class'));
});
And to conclude, the id of an element is ment to be unique because it makes searching through big documents alot faster. Also don't forget to look and learn plain javascript, as it helps coding in jQuery alot too, but not the other way around. Your given question would require a for loop in plain javascript since it cannot do a lookup by class nor id nor have they have a common parent.
Good luck with learning :)
What I am trying to do is populate data in a select element. I'm using the following code, where a user selects a SubjectCategory from one drop down, which then should populate the next select element's html. The handler itself is working just fine, it returns the correct html I need to place inside the select element.
Also, keep in mind that I eventually clone both of these select elements and will need to populate them accordingly.
The problem is that $elem is always returning null.
I'm guessing that it's a problem with this line of code, however not quite sure (keeping in mind that I'm also cloning these two select elements):
var $elem = $this.closest('div').prev().find('select');
$(".SubjectCategory").live("click", function () {
var $this = $(this);
var $elem = $this.closest('div').next().find('select');
var a = $this.val();
$.get("/userControls/BookSubjectHandler.ashx?category=" + a, {}, function (data) {
$elem.html(data);
});
});
<div class="singleField subjectField">
<label id="Category" class="fieldSml">Subject Matter</label>
<div class="bookDetails ddl"><select id="ddlSubjectMatter" class="fieldSml SubjectCategory"></select></div>
<label id="Subjects" class="fieldSml">Category</label>
<div class="bookDetails ddl" id="subjectMatter"><select id="ddlSubjects" class="fieldSml Subjects"></select></div>
</div>
You're searching inside the <label>, not the next <div> as you want. next only gets one element after the current one.
Try this: It searches for the first div next to your parent element.
var $elem = $this.closest('div').nextAll('div').first().find('select');
Given that the source element has an id of ddlSubjectMatter and the target select element has an id of subjectMatter, it may be a lot simpler to capitalise the first letter of the second id (i.e. make SubjectMatter) then you get the second element by:
var elem = document.getElementById(this.id.replace(/^ddl/,''));
It makes the element relationship independent of the document layout.
Incidentally, it is invalid HTML to have select elements with no options, not that it is a big issue.
Why are you creating an extraneous $this variable? Unless you've omitted code that requires it for a different scope, just call $(this). That might be causing the problem, too.
I googled and googled and I concluded that it's very hard to get answer on my own.
I am trying to use jquery or JavaScript to get a property of clicked element. I can use "this.hash" for example - it returns hash value I presume.
Now I would like to get name of the class of clicked element.
Is it even possible? How? And where would I find this kind of information?
jQuery documentation? - All I can find is methods and plugins, no properties.. if its there - please provide me with link.
JavaScript documentation? - is there even one comprehensive one? again please a link.
DOM documentation? - the one on W3C or where (link appreciated).
And what is this.hash? - DOM JavaScript or jQuery?
In jQuery, if you attach a click event to all <div> tags (for example), you can get it's class like this:
Example: http://jsfiddle.net/wpNST/
$('div').click(function() {
var theClass = this.className; // "this" is the element clicked
alert( theClass );
});
This uses jQuery's .click(fn) method to assign the handler, but access the className property directly from the DOM element that was clicked, which is represented by this.
There are jQuery methods that do this as well, like .attr().
Example: http://jsfiddle.net/wpNST/1/
$('div').click(function() {
var theClass = $(this).attr('class');
alert( theClass );
});
Here I wrapped the DOM element with a jQuery object so that it can use the methods made available by jQuery. The .attr() method here gets the class that was set.
This example will work on every element in the page. I'd recommend using console.log(event) and poking around at what it dumps into your console with Firebug/Developer tools.
jQuery
$(window).click(function(e) {
console.log(e); // then e.srcElement.className has the class
});
Javascript
window.onclick = function(e) {
console.log(e); // then e.srcElement.className has the class
}
Try it out
http://jsfiddle.net/M2Wvp/
Edit
For clarification, you don't have to log console for the e.srcElement.className to have the class, hopefully that doesn't confuse anyone. It's meant to show that within the function, that will have the class name.
$(document).click(function(e){
var clickElement = e.target; // get the dom element clicked.
var elementClassName = e.target.className; // get the classname of the element clicked
});
this supports on clicking anywhere of the page. if the element you clicked doesn't have a class name, it will return null or empty string.
$('#ele').click(function() {
alert($(this).attr('class'));
});
And here are all of the attribute functions.
http://api.jquery.com/category/attributes/
You can use element.className.split(/\s+/); to get you an array of class names, remember elements can have more than one class.
Then you can iterate all of them and find the one you want.
window.onclick = function(e) {
var classList = e.srcElement.className.split(/\s+/);
for (i = 0; i < classList.length; i++) {
if (classList[i] === 'someClass') {
//do something
}
}
}
jQuery does not really help you here but if you must
$(document).click(function(){
var classList =$(this).attr('class').split(/\s+/);
$.each( classList, function(index, item){
if (item==='someClass') {
//do something
}
});
});
There's a way to do this without coding. Just open the console of your browser (f12?) and go to element you want. After that, hover or click the item you want to track.
Every change done on the DOM will be for a few seconds marked (or lightened) as another color on the console. (Watch the screen capture)
On the example, each time I hover a "colorItem", the 'div' parent and the "colorItem" class appears lightened. So in this case the clicked class will be 'swiper-model-watch' or 'swiper-container' (class of the lightened div)
How can I get attributes values from an container using jquery ?
For example:
I have container div as:
<div id = "zone-2fPromotion-2f" class = "promotion">
here how can I get attribute id value using jquery and than how can I trim the value to get component information ?
update : how can i get attribute values ?
UPDATE: If I have multiple components on page with same div information than how would I know what attribute value is for which component ?
Thanks.
First, that seems to be a ridiculously long ID -- I'm sure it could be made much shorter while still retaining its uniqueness.
Anyway, on to the answer: First you need a way of accessing your "container" div. Typically, one might use a class or ID to get an element. For example, you could "select" this div with the following call to jQuery:
var container = jQuery('#zone-3a...'); // Fill in ... with really long ID
But, since you're asking how to retrieve the ID, I'm presuming that selecting it via the ID is not an option. You could also select it using the class, although it's not guarenteed to be the only element on the page with that class:
var container = jQuery('.promotion');
There are other ways to narrow down the search, such as:
jQuery('div.promotion');
jQuery('div.promotion:first');
Once you have a reference to your "container", you can retrieve the ID like so:
container.attr('id'); // => zone-3a...
// or:
container[0].id; // => zone-3a...
So assuming your div looks like this.
<div id="foo"/>
You could get the ID attribute by using the attr method.
$("div").attr("id);
That assumes that you only have one div on the page. Not really sure what component information you are looking to get?
You read node attributes with the attr() method.
var id = $( '.promotion' ).attr( 'id' );
In terms of parsing that ID for any other arbitrary information, I can't say since it looks like you're using some sort of proprietary format of which I have no knowledge.
loop thru and get all divs with the class promotion and get the id of each...
$('div.promotion').each(function(){
var attr = $(this).attr('id'); // or whatever attribute
});
or single
var myDivClass = $('zone-3a-2f-2f-2fPortal-2fPages-2fHome-2fZones-2fLeft-2f-7ccomponent-3a-2f-2f-2fSpm-2fComponents-2fPromotion-2f').attr('class');
or another single
var myDivID = $('.promotion').attr('id');