I'm using a javascript function to set the value of a text field, based on the option chosen from a select field.
The javascript contains a lot of other stuff, but only the following is relevant to this question.
$(function (){
$('.source').live("change", function(e) {
var target = $(this).next('.target')[0];
----other stuff----
});
});
I originally had my form set up as follows, and everything worked fine.
<select class="source"></select>
<input class="target"></input>
I've subsequently added some styling, which has required extra divs.
<select class="source"></select>
<div class="level1">
<div class="level2">
<input class="target"></input>
</div>
</div>
Now the javascript function does not work, because the next method only targets siblings and not descendants.
So my question is, what method should I be using to target a specific descendant?
An important fact: this markup is part of a nested form, and is repeated several times on the same page. It is important that the function targets the correct .target field, i.e. immediately subsequent and descendant.
I've tried obvious candidates – .find(), .children() — but these don't seem to work. Would appreciate any ideas or pointers.
Thanks!
Now that in the new markup structure .target input is wrapped in a div with class level1 you can find that div first using next() and then use find() method to get to the .target input.
$(function (){
$('.source').live("change", function(e) {
var target = $(this).next('.level1').find('.target')[0];
----other stuff----
});
});
Note: Even if you don't pass any selector to next() also it will work fine because it only selects the immediate next sibling optionally filtered by the selector which we pass.
In your case this would work:
$(function (){
$('.source').live("change", function(e) {
var target = $(this).next().find('.target')[0];
----other stuff----
});
})
;
It's a descendant of the sibling, so this should do the trick:
var target = $(this).next('.level1').find('.target')[0];
Related
I dont know Javascript at all, so sorry for asking a question like this...
This is what I have:
$(document).ready(function(){$("#more0").click(function(){$("#update0").slideToggle("normal");});});
$(document).ready(function(){$("#more1").click(function(){$("#update1").slideToggle("normal");});});
$(document).ready(function(){$("#more2").click(function(){$("#update2").slideToggle("normal");});});
$(document).ready(function(){$("#more3").click(function(){$("#update3").slideToggle("normal");});});
$(document).ready(function(){$("#more4").click(function(){$("#update4").slideToggle("normal");});});
$(document).ready(function(){$("#more5").click(function(){$("#update5").slideToggle("normal");});});
$(document).ready(function(){$("#more6").click(function(){$("#update6").slideToggle("normal");});});
$(document).ready(function(){$("#more7").click(function(){$("#update7").slideToggle("normal");});});
$(document).ready(function(){$("#more8").click(function(){$("#update8").slideToggle("normal");});});
$(document).ready(function(){$("#more9").click(function(){$("#update9").slideToggle("normal");});});
$(document).ready(function(){$("#more10").click(function(){$("#update10").slideToggle("normal");});});
And So On.. Until #more30 and #update30...
So... Right now, my pages has 30 lines :)
Is there a way to do it less complicated?
Thanks!
Use attribute selector ^= . The [attribute^=value] selector is used to select elements whose attribute value begins with a specified value.
$(document).ready(function(){
$("[id^='more']").click(function(){
$("#update" + $(this).attr('id').slice(4)).slideToggle("normal");
});
});
Try to use attribute starts with selector to select all the elements having id starts with more , then extract the numerical value from it using the regular expression and concatenate it with update to form the required element's id and proceed,
$(document).ready(function(){
$("[id^='more']").click(function(){
var index = $(this).attr('id').match(/\d+/)[0];
$("#update" + index).slideToggle("normal");
});
});
use attribute start with selector
$(document).ready(function(){
$("[id^='more']").click(function(){
$("[id^='update']").slideToggle("normal");
});
});
//select all elements that contain 'more' in their id attribute.
$('[id^=more]').click(function(){
//get the actual full id of the clicked element.
var thisId = $(this).attr("id");
//get the last 2 characters (the number) from the clicked elem id
var elemNo= thisId.substr(thisId.length-2);
//check if last two chars are actually a number
if(parseInt(elemNo))
{
var updateId = "#update"+elemNo;//combine the "#update" id name with number e.g.5
}
else
{
//if not, then take only the last char
elemNo= thisId.substr(thisId.length-1);
var updateId = "#update"+elemNo;
}
//now use the generate id for the slide element and apply toggle.
$(updateId).slideToggle("normal");
});
Well first of all, you could replace the multiple ready event handler registrations with just one, e.g
$(document).ready(
$("#more0").click(function(){$("#update0").slideToggle("normal");});
//...
);
Then, since your buttons/links has pretty much the same functionality, I would recommend merging these into a single click event handler registration as such:
$(document).ready(
$(".generic-js-hook-class").click(function(){
var toggleContainer = $(this).data('toggleContainer');
$(toggleContainer).slideToggle("normal");
});
);
The above solution uses HTML Data Attributes to store information on which element to toggle and requires you to change the corresponding HTML like so:
<div class=".generic-js-hook-class" data-toggle-container="#relatedContainer">Click me</div>
<div id="relatedContainer>Toggle me</div>
I would recommend you to use Custom Data Attributes (data-*). Here You can store which element to toggle in the data attributes which can be fetched and used latter.
JavaScript, In event-handler you can use .data() to fetch those values.
$(document).ready(function () {
$(".more").click(function () {
$($(this).data('slide')).slideToggle("normal");
});
});
HTML
<div class="more" data-slide="#update1">more1</div>
<div class="more" data-slide="#update2">more2</div>
<div id="update1">update1</div>
<div id="update2">update2</div>
DEMO
I have an element which listens to the onclick event. It calls a function once it was clicked. After that element is a < dd > which I want to select in a CSS selector. The element which is clicked, is a < select >. How would I do that?
This is the HTML:
<select onclick="myFunction();">...</select>
<dd>...</dd>
function myFunction() {
// What do I have to write for the ??????
$$('?????? dd').toggle();
}
Note: There are many of those select/dd combination, so I really have to get the next dd after the firing element.
The minimal change is: Pass this into your function:
<select onclick="myFunction(this);">...</select>
...and then:
function myFunction(select) {
$(select).next().toggle();
}
$ enhances the element, then you can use next to move to the next element. If you like, you can use .next('dd'), but in your case the dd is the next element.
That still uses onxyz attributes, which is a bit old-hat. You might consider hooking things up via observe instead.
I am guessing you mean this:
this.next("dd");
(specifying dd so when there's an error in the mark up, no other element is selected)
If you are trying CSS selectors only, try the following:
$("select + dd").toggle();
Note: this will toggle all dds that follow a select.
Note 2: apparently this does not work in Prototype but it does work in jQuery.
See T.J.Crowder's comment:
[This doesn't work in Prototype] because $ in Prototype looks up elements by ID. $$ is more like
jQuery's $, but what it returns doesn't do set-based operations like
jQuery does (or rather, not the same set-based operations as the ops
you can do on individual elements; you have to use invoke).
next() works on both jQuery as Prototype.
Use:
$(this).next("dd").toggle(); --> this is Jquery
$(element).next("dd").toggle();
see the link Element.next
<select>...</select>
<dd>...</dd>
$('select').change(function(){
$(this).next("dd").toggle();
});
Better use unobtrusive javascript, so your js is better coupled from html markup.
HTML:
<select><option value="test">Test</option></select>
<dd>Test</dd>
JS:
//Event.observe(window, "load", function() {
document.observe('dom:loaded', function() {
$$('select')[0].observe('click', function(event) {
var next = event.element().next();
next.toggle();
});
});
JSFiddle
I have a couple of drop down boxes with ids country1, country2, ... When the country is changed in a drop down the value of the country shoudl be displayed in an alert box.
if I add the onchange handler for one box like this it works fine:
$('#country1') .live('change', function(e){
var selectedCountry = e.target.options[e.target.selectedIndex].value;
alert(selectedCountry);
});
But I need to do this dynamically for all drop down boxes so I tried:
$(document).ready(function() {
$('[id^=country]') .each(function(key,element){
$(this).live('change', function(e){
var selectedCountry = e.target.options[e.target.selectedIndex].value;
alert(selectedCountry);
});
});
});
This doesn't work. No syntax error but just nothing happens when the seleted country is changed. I am sure that the each loop is performed a couple of times and the array contains the select boxes.
Any idea on that?
Thanks,
Paul
The reason .live() existed was to account for elements not present when you call the selector.
$('[id^=country]') .each(function(key,element){ iterates over elements that have an id that starts with country, but only those that exist when you run the selector. It won't work for elements that you create after you call .each(), so using .live() wouldn't do you much good.
Use the new style event delegation syntax with that selector and it should work:
$(document).on('change', '[id^=country]', function(e) {
// ...
});
Replace document with the closest parent that doesn't get dynamically generated.
Also, consider adding a class to those elements along with the id attribute.
Instead of incremental ids I'd use a class. Then the live method is deprecated but you may use on with delegation on the closest static parent or on document otherwise.
$('#closestStaticParent').on('change', '.country', function() {
// this applies to all current and future .country elements
});
You don't need an each loop this way; plus events are attached to all the elements in the jQuery collection, in this case all .country elements.
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.
This question already has answers here:
jquery stop child triggering parent event
(7 answers)
Closed 8 years ago.
I am not sure this is really bubbling, I will explain.
I have this:
<div>
<div>
text here
</div>
</div>
How to bind an on click event so that it will affect only the enclosed div? If I set it like this:
jQuery('div').bind('click', function() {
jQuery(this).css('background','blue');
});
it makes blue all the divs. If I add false as the third argument(prevent bubbling) to the bind function it does nothing.
How can I solved this?
http://api.jquery.com/event.stopPropagation/
Add event.stopPropagation(); inside the hander.
(It might be better, though, to assign an ID or class to the nested DIV so you can be sure it's the only one affected.)
You should really use identifiers like IDs or classes, but for your example, you could do this:
jQuery('div > div').bind('click', function() {
jQuery(this).css('background','blue');
});
...which will bind the handler to any div that is a direct descendant of another div.
So either make your initial selection specific to the element(s) you want to affect, or use event delegation, placing a handler on an ancestor, and testing for the element you want.
Delegation example: http://jsbin.com/ehemac/edit#javascript,live
<div id="container">
<div class="outer">
<div>
text here
</div>
</div>
<div class="outer">
<div>
text here
</div>
</div>
</div>
jQuery('#container').delegate( '.outer > div', 'click', function() {
jQuery(this).css('background','blue');
});
This uses the delegate()[docs] method that places a handler on the ancestor with the ID #container.
The first argument to .delegate() is a selector. Any elements that are clicked inside #container will have that selector compared against the element clicked. If the selector matches, the handler will be invoked.
http://jsfiddle.net/vol7ron/WzSkj/
Targeting the last descendant
Credit to Patrick DW:
jQuery('div:not(:has(div))').bind('click', function() {
jQuery(this).css('background','blue');
});
This should be all you need as it will look at all div and find those that don't have child divs (thus, they will be the last descendant of that element type. You could further filter this to make sure they have a parent that is a div, if you wanted to exclude those divs that are standalone.
Older Answer:
This is not by any means meant to be a complete/robust plugin. It serves as only an example of how to target the last element in a chain. See the revision history for a way to do it w/o the plugin. This should be modified if you wish to use it for production.
Plugin:
(function($){
$.fn.lastDescendant = function(el){
var found = jQuery(el + ':first').siblings(el).andSelf();
var prev, curr;
var stack = this;
for (var i=0,n=found.length; i<n; i++){
curr = found.eq(i).find(el);
while (curr.length){
prev = curr;
curr = curr.find(el);
}
stack = stack.add(prev);
}
return stack;
};
})( jQuery );
Example Call:
jQuery.fn.lastDescendant('div')
.click(function(){
jQuery(this).css("background","#09c");
});
Note:
this will not select the first (ancestor) element. If you want to select that as well, you could wrap the whole thing in a new div, and then do the above.
if I were to make this a production plugin, I would include checking the parameter, and allow you to be able to pass in an object and a starting point (so that siblings are not selected)
To fix this just use a more specific selector
jQuery('div > div').bind('click', function() {
jQuery(this).css('background','blue');
})
The best way to solve it would be to give your inner div an identifiable feature such as a class, e.g., <div class="inner"></div>.
Alternatively, change your selector:
$('div > div').click(function() {
$(this).css('background', 'blue');
}
try giving the inner div an id tag and refer to it...
<div><div id=foo>text goes here</div></div>
...
$('#foo').bind('click', function() {
$(this).css('background','blue');
});
HTH
-- Joe