We are having an issue where when we open a modal window we are trying to set the focus to the first input element in the modal that is not of type hidden. here is what we are trying:
$("#test-overlay input[type!=hidden]:first").focus();
However, this call works:
$("#test-overlay #loginInput").focus();
The input field has an id of loginInput.
Any thoughts?
The problem is due to the order of precedence in which jQuery interprets the selector. Try the following:
$('#test-overlay input').not('[type=hidden]').first().focus();
This has the added benefit of not using the :first and attribute not equal to selectors since they're jQuery specific and queries using these cannot take advantage of the performance boost provided by the native DOM querySelectorAll() method.
Related
I have a page with duplicate ID's for a form element. The catch is I the elements show up separately based on a toggle. So both ID's never show up simultaneously.
However when I do form validation on that element, it always selects the element displayed last in the code (even if its hidden).
Is there a selector to select the visible duplicate ID?
I've tried the following but to no avail:
$('#my_element:visible').val();
As the myriad of other questions about this premise will tell you, you cannot use the ID selector # in this case; you have to use something like $('div[id=foo]') to find it.
Duplicate IDs are invalid HTML and will nearly always cause issues with scripting. Avoid if at all possible.
The reason this is occurring is because of Duplicate IDs. IDs must be unique for the HTML to be considered valid. Whenever you aren't working against valid HTML, your results are often erratic.
In this case, even though you are only showing one of the forms at a time, they're both still present in the mark up which is why the last one in the code is always the one that's getting run.
Since you're using jQuery, I'd highly recommend using classes for this instead.
Avoid duplicates ids on the page. It is not a valid HTML.
as Rwwl said, duplicate IDs are invalid. Assign classes instead of ids to them.
Then you can do
alert($('.my_element:visible').val());
try :hidden
$("#my_element").find(":hidden").val();
Elements can be considered hidden for several reasons:
They have a CSS display value of none.
They are form elements with type="hidden".
Their width and height are explicitly set to 0.
An ancestor element is hidden, so the element is not shown on the page.
NOTE: Elements with visibility: hidden or opacity: 0 are considered to be visible,
Do not use same id for multiple elements, classes are better!
You can not specify using the # id selector only, you need to be more specific. One way is choose the type of element first then id:
For an input element:
$('input#my_element:visible').val();
or for a div element:
$('div#my_element:visible').val();
An alternative solution to select the element with jQuery and then get value from from the element directly:
$('#my_element:visible')[0].value
I'm trying to select the 3rd element of a JQuery object, by using eq() method. But for some reason the 2nd and 3rd selections pop out in changed order:
var selection = $("[name=input0], [name=input1], [name=input2], [name=input3]");
selection.eq(1); //turns out to be input2!!
What could be the reasons for this behavior? Can I trust acessing it by index in my script?
According to:
https://api.jquery.com/multiple-selector/
The order of the DOM elements in the returned jQuery object may not be identical, as they will be in document order.
With the help of the answers and comments and a bit of reading on the documentation.
Turns out that jQuery selects elements in the order they appear in the DOM (HTML), so:
Using a direct array access to a jQuery selection will work if you use that order, but you can only trust it if you are also responsible for the HTML, and you would need to remember this if you are ever going to change the layout.
Bottom line: not the best way to select a specific element.
I want to toggle(hide/show) an element when a button is being pressed. I have two ways as to implement this:
Find the element according to its class name, e.g $('.my-content')
Find the element according to its relevant DOM position towards the button, e.g. $('#my-button').parent().next().next().next()
However, none of the above seems to me very reliable since in case someone changes the HTML code, the above approaches should not work. Is there something more reliable I am missing?
If it's a specific element, supply it with an Id value and use that
to find it.
If it's a TYPE of element, use a class name.
Other than that, there's no real conventions. Just try and make sure that somebody reading your code understands what is going on.
A very good practice is to decouple HTML, CSS and JS.
When binding javascript to DOM elements you should use javascript selectors.
Basically classes with some custom prefix (like js-) which will be used only for javascript purposes (not css style).
So whenever the DOM tree structure or the CSS class names are changed, you can still have your working JS selector
HTML
<div class="my-content js-toggle-element"></div>
JS
$('.js-toggle-element')
CSS
.my-content{ ... }
Plus, using Javascript Selectors:
makes HTML highly readable: you can easily find out what will happen to that element with that js class
allows you to easily apply/disapply that behaviour also to other elements in the future, simply by adding/removing that class in your HTML and without affecting CSS at all
<div class="my-content js-toggle-element"></div>
...
<div class="another-content-to-toggle js-toggle-element"></div>
Using jQuery will be much easiest way. Like this -
$( ".target" ).toggle();
The matched elements will be revealed or hidden immediately, with no animation, by changing the CSS display property. If the element is initially displayed, it will be hidden; if hidden, it will be shown.
Reference - jQuery Toggle
If the class or the position of the element in DOM is changing then you can try
selecting it with the inner text
$("button:contains('buttontextgoeshere')")
so I have a page with multiple forms and I would like to be able to access input elements of type="datetime" within a particular form. I know I can do $('input[type="datetime"]') but that would give me all input tags on the page. I also cannot use the "form" attribute because not all browser use it (Sigh IE). Worse scenario for me is to do something like:
$(document.forms["..."].elements).each(function() {
if (this.type="datetime") {.....}
});
but I am sure this can be done in jQuery with one selector. Can someone tell me how do this with one selector?
Add id to your form and then select DOM inside of that form as below.
$('#form input[type="datetime"]')
Without seeing some HTML this is just a shot in the dark. But if you give your forms an id you can do:
$("#yourFormId input[type='datetime']");
If you do not have ids, but you know the number, then this might do it:
$("form:eq(4) input[type='datetime']");
There are multiple ways to do it
Solution 1.
use descendant selector
ex:
$('#yourform input[type="datetime"]') //or
$('.yourform input[type="datetime"]') //or
$('form:eq(3) input[type="datetime"]')
Solution 2:
Use context based look up
Ex:
$('input[type="datetime"]', yourform)
I have a page with duplicate ID's for a form element. The catch is I the elements show up separately based on a toggle. So both ID's never show up simultaneously.
However when I do form validation on that element, it always selects the element displayed last in the code (even if its hidden).
Is there a selector to select the visible duplicate ID?
I've tried the following but to no avail:
$('#my_element:visible').val();
As the myriad of other questions about this premise will tell you, you cannot use the ID selector # in this case; you have to use something like $('div[id=foo]') to find it.
Duplicate IDs are invalid HTML and will nearly always cause issues with scripting. Avoid if at all possible.
The reason this is occurring is because of Duplicate IDs. IDs must be unique for the HTML to be considered valid. Whenever you aren't working against valid HTML, your results are often erratic.
In this case, even though you are only showing one of the forms at a time, they're both still present in the mark up which is why the last one in the code is always the one that's getting run.
Since you're using jQuery, I'd highly recommend using classes for this instead.
Avoid duplicates ids on the page. It is not a valid HTML.
as Rwwl said, duplicate IDs are invalid. Assign classes instead of ids to them.
Then you can do
alert($('.my_element:visible').val());
try :hidden
$("#my_element").find(":hidden").val();
Elements can be considered hidden for several reasons:
They have a CSS display value of none.
They are form elements with type="hidden".
Their width and height are explicitly set to 0.
An ancestor element is hidden, so the element is not shown on the page.
NOTE: Elements with visibility: hidden or opacity: 0 are considered to be visible,
Do not use same id for multiple elements, classes are better!
You can not specify using the # id selector only, you need to be more specific. One way is choose the type of element first then id:
For an input element:
$('input#my_element:visible').val();
or for a div element:
$('div#my_element:visible').val();
An alternative solution to select the element with jQuery and then get value from from the element directly:
$('#my_element:visible')[0].value