rails jquery change event not working - ruby-on-rails

I am building a rails app where I want to simply fire code when a user selects an option on a element (unobtrusively). I have read that the most supported way of doing this is by attaching the element directly to the change event:
$('#country_selection').change(function() { alert('it works'); });
However, for me, this is not working. If I put it in the console, it works just fine. However, putting it in the js file of my view, it does not work. I know my js file is being loaded because inserting a simple alert('in the js file'); returns just fine. The other strange part is that using the live method works:
$('#country_selection').live('change', function() { alert('hello'); });
However, I do not want to do this b/c it is not as supported. The other option I tried which does not work is the 'delegate' method:
$('#country_selection').delegate('change', function() { alert('hello'); });
Why isn't my change function working?

If you have a select element like
<select id="my-select-box">
<option value="1">First Value</option>
<option value="2">Second Value</option>
</select>
Then the following Jquery code should work
$('#my-select-box').change(function() {
alert("hey, i got changed");
});
It is imperative that the DOM is loaded before JQuery binds your code to the selector. To do this, ensure that you have your code within an anonymous function as such:
jQuery(function(){
$('#my-select-box').change(function() {
alert("hey, i got changed");
});
});
This ensures that the DOM is loaded before the JQuery executes and tries to bind. Otherwise the JavaScript will execute before the element is loaded, and it will not execute correctly.

Related

jQuery unobtrusive custom adapter and method in jsFiddle

I cannot make this jsFiddle work but it works in the browser: http://jsfiddle.net/vtortola/jYq2X/
I am trying to add a new custom rule to compare two fields. The custom adapter works, it is being called and setting the options. But the custom method is never called.
I am executing this JS on DOM ready:
$.validator.addMethod("customequal-method", function (val, el, p) {
var $other = $(el).closest('form').find('input[name=' + p.other + ']');
return $other.length && $other.val() == val;
});
$.validator.unobtrusive.adapters.add("customequal", ["other"],
function (options) {
options.rules["customequal-method"] = options.params;
options.messages["customequal-method"] = options.message;
});
$(function(){
$.validator.unobtrusive.parse($('#myform'));
$('[type=button]').click(function(e){e.preventDefault(); $('form').valid();});
$('input[type=text]').blur();
})
These are the fields in HTML:
<input type="text" name="StartDate2" id="StartDate2" value="2"
data-val="true" data-val-customequal="xx xxx" data-val-customequal-other="EndDate2"/>
<input type="text" name="EndDate2" id="EndDate2" value="3"
data-val="true" data-val-customequal="xx xx" data-val-customequal-other="StartDate2"/>
I have been trying different things but nothing seems to work.
Any idea?
Your fiddle is not working because:
all your code runs in the DOM ready so you are adding your custom unobtrusive.adapters.add after the unobtrusive.validator plugin called unobtrusive.parse(document) which registers all the inputs without your custom validator
if you call .validate() multiple times it only registers the rules for the first time and does not override them on subsequent calls. So although you've called unobtrusive.parse again in the DOM loaded this time with the custom adapter added it still won't have any effect.
So you have two ways to fix it:
Register your custom adapters before the DOM loaded event, you can do this with changing your fiddle to use
"No wrap - in <head>"
Demo JSFiddle.
Or
Remove the already added validator object with using $('#myform').data('validator', null) before calling unobtrusive.parse manually:
$(function () {
$('#myform').data('validator', null);
$.validator.unobtrusive.parse($('#myform'));
$('[type=button]').click(function (e) {
e.preventDefault();
$('form').valid();
});
$('input[type=text]').blur();
})
Demo JSFiddle.

Jquery mobile How to tap the screen to no avail

I tested on the Apple device, and when I click on the screen when there is no effect. This is my code. Click on the events of this writing there are questions?
<script>
$(function() {
$('#test').tap(function() {
$('#menuNum').text('1');
})
})
</script>
You need to change few things.
Do not use $(function() { or classic document ready to check for a correct state, they can cause problems with jQuery Mobile. Instead use jQuery Mobile alternative called page events.
Then don't bind tap event like that, use proper modern way of doing that. In your case element must be loaded into the DOM for that kind of binding to work. And because of $(function() { sometimes it can happen that element is still loading when binding is executed. So use it like this:
$(document).on('tap','#test',function() {
$('#menuNum').text('1');
});
This method don't care if element exist or not, it will even work if element is loaded into the DOM after binding process.
Working example: http://jsfiddle.net/Gajotres/SQ7DF/
In the end you want something like this:
$(document).on('pagebeforeshow', '#index', function(){
$(document).on('tap','#test',function() {
alert('Tap');
});
});

jQuery UI in Backbone View adds elements, but doesn't respond to events

I'm building an app in which I'm using Django on the backend and jQuery UI/Backbone to build the front. I'm pulling a Django-generated form into a page with jQuery.get() inside of a Backbone View. That part works fine, but now I want to add some jQuery UI stuff to the form (e.g. a datepicker, some buttons that open dialogs, etc). So, here's the relevant code:
var InstructionForm = Backbone.View.extend({
render: function() {
var that = this;
$.get(
'/tlstats/instruction/new/',
function(data) {
var elements = $(data);
$('#id_date', elements).datepicker();
that.$el.html(elements.html());
}
};
return this;
}
});
The path /tlstats/instruction/new/ returns an HTML fragment with the form Django has generated. What's happening is that input#id_date is getting the hasDatePicker class added and the datepicker div is appended to my <body> element (both as expected), but when I click on input#id_date, nothing happens. No datepicker widget appears, no errors in the console. Why might this be happening?
Also, somewhat off-topic, but in trying to figure this problem out on my own, I've come across several code examples where people are doing stuff like:
$(function() {
$('#dialog').dialog(...);
...
});
Then later:
var MyView = Backbone.View.extend({
initialize(): function() {
this.el = $('#dialog');
}
});
Isn't this defeating the purpose of Backbone, having all that jQuery UI code completely outside any Backbone structure? Or do I misunderstand the role of Backbone?
Thanks.
I think your problem is right here:
$('#id_date', elements).datepicker();
that.$el.html(elements.html());
First you bind the datepicker with .datepicker() and then you throw it all away by converting your elements to an HTML string:
that.$el.html(elements.html());
and you put that string into $el. When you say e.html(), you're taking a wrapped DOM object with event bindings and everything else and turning into a simple piece of HTML in a string, that process throws away everything (such as event bindings) that isn't simple HTML.
Either give .html() the jQuery object itself:
$('#id_date', elements).datepicker();
that.$el.html(elements);
or bind the datepicker after adding the HTML:
that.$el.html(elements);
that.$('#id_date').datepicker();

jQuery / jQuery UI - $("a").live("click", ...) not working for tabs

So I have some jQuery UI tabs. The source code is as follows:
HTML:
<div class="tabs">
<ul>
<li>Ranges</li>
<li>Collections</li>
<li>Designs</li>
</ul>
<div id="ranges"></div>
<div id="collections"></div>
<div id="designs"></div>
</div>
jQuery:
$(document).ready(function() {
$(".tabs").tabs();
});
My problem is that I am trying to make each tab load a page into the content panel on click of the relevant link. To start with I am just trying to set the html of all the panels on clicking a link. From the code below, if I use method 1, it works for all links. However if I use method 2 it doesn't - but only for the links in the tabs (i.e. the labels you click to select a tab).
Method 1 (works for all links all the time, but would not be applied to links which are added after this is called):
$("a").click(function () {
$("#ranges, #collections, #designs").html("clicked");
});
Method 2 (works for all links which are not "tabified"):
$("a").live("click", function () {
$("#ranges, #collections, #designs").html("clicked");
});
Does anyone know why it is behaving like this? I would really like to get method 2 working properly as there may well be links which I need to add click events to which are added after the page is originally loaded.
Thanks in advance,
Richard
PS yes the function calls for .live and .click are both in the $(document).ready() function, before anyone says that that may be the problem - otherwise it wouldn't work at all..
Edit:
The solution I came up with involves an extra attribute in the anchors (data-url) and the following code (which outputs a 404 not found error if the page cannot be loaded). I aim to expand this over the next few weeks / months to be a lot more powerful.
$(".tabs").tabs({
select: function (event, ui) {
$(ui.panel).load($(ui.tab).attr("data-url"), function (responseText, textStatus, XMLHttpRequest) {
switch (XMLHttpRequest.status) {
case 200: break;
case 404:
$(ui.panel).html("<p>The requested page (" + $(ui.tab).attr("data-url") + ") could not be found.</p>");
break;
default:
$(ui.panel).html("<p title='Status: " + XMLHttpRequest.status + "; " + XMLHttpRequest.statusText + "'>An unknown error has occurred.</p>");
break;
};
});
}
});
I don't know if I understand what you are going for but basically you want to do something once a tab is clicked?
Here's the docs for setting up a callback function for selecting a tab.
EDIT: Don't know if that link is working correctly, you want to look at select under Events. But basically it is:
$("#tabs").tabs({
select: function(event, ui) { ... }
});
Where ui has information on the tab that was clicked.
jQuery UI tabs has an outstanding issue where return false; is used instead of event.preventDefault();. This effectively prevents event bubbling which live depends on. This is scheduled to be fixed with jQuery UI 1.9 but in the meantime the best approach is use the built in select event as suggested by #rolfwaffle.
Maybe the tabs() plugin that you are using is calling event.preventDefault(); (Reference) once it has created it's tabs.
Then it captures the click event and the bubbling stops, so it doesn't invoke your click-function. In jQuery this is done with
$(element).click(function(){
// Do stuff, then
return false; // Cancels the event
});
You'd have to alter the tabs() plugin code and remove this return false; statement, OR if you are lucky, the plugin might have an option to disable that behavior.
EDIT: Now I see you're using jQuery UI. Then you should check the documentation there, since it is an awesome plugin, it will do anything you want if you do the html right and pass it the right options.

Bind jQuery UI autocomplete using .live()

I've searched everywhere, but I can't seem to find any help...
I have some textboxes that are created dynamically via JS, so I need to bind all of their classes to an autocomplete. As a result, I need to use the new .live() option.
As an example, to bind all items with a class of .foo now and future created:
$('.foo').live('click', function(){
alert('clicked');
});
It takes (and behaves) the same as .bind(). However, I want to bind an autocomplete...
This doesn't work:
$('.foo').live('autocomplete', function(event, ui){
source: 'url.php' // (surpressed other arguments)
});
How can I use .live() to bind autocomplete?
UPDATE
Figured it out with Framer:
$(function(){
$('.search').live('keyup.autocomplete', function(){
$(this).autocomplete({
source : 'url.php'
});
});
});
jQuery UI autocomplete function automatically adds the class "ui-autocomplete-input" to the element. I'd recommend live binding the element on focus without the "ui-autocomplete-input"
class to prevent re-binding on every keydown event within that element.
$(".foo:not(.ui-autocomplete-input)").live("focus", function (event) {
$(this).autocomplete(options);
});
Edit
My answer is now out of date since jQuery 1.7, see Nathan Strutz's comment for use with the new .on() syntax.
If you are using the jquery.ui.autocomplete.js try this instead
.bind("keydown.autocomplete") or .live("keydown.autocomplete")
if not, use the jquery.ui.autocomplete.js and see if it'll work
If that doesn't apply, I don't know how to help you bro
Just to add, you can use the .livequery plugin for this:
$('.foo').livequery(function() {
// This will fire for each matched element.
// It will also fire for any new elements added to the DOM.
$(this).autocomplete(options);
});
To get autocomplete working when loaded dynamically for the on() event used in jQuery > 1.7, using the syntax Nathan Strutz provides in his comment:
$(document).on('focus', '.my-field:not(.ui-autocomplete-input)', function (e) {
$(this).autocomplete(options)
});
where .my-field is a selector for your autocomplete input element.
.live() does not work with focus.
also keyup.autocmplete does not make any sense.
Instead the thing I have tried and working is this
$(document).ready(function(){
$('.search').live('keyup' , function()
{
$(this).autocomplete({ source : 'url.php' });
});
})
This works perfectly fine.
You can't. .live() only supports actual JavaScript events, not any custom event. This is a fundamental limitation of how .live() works.
You can try using this:
$('.foo').live('focus.autocomplete', function() {
$(this).autocomplete({...});
});
After reading and testing everyone else's answers I have updated it for the current version of JQuery and made a few tweaks.
The problem with using keydown as the event that calls .autocomplete() is that it fails to autocomplete for that first letter typed. Using focus is the better choice.
Another thing I have noticed is that all of the given solutions result in .autocomplete() being called multiple times. If you are adding an element dynamically to the page that will not be removed again, the event should only be fired once. Even if the item is to be removed and added again, the event should be removed and then added back each time the element is removed or added so that focusing on the field again will not unnecessarily call .autocomplete() every time.
My final code is as follows:
$(document).on('focus.autocomplete', '#myAutocomplete', function(e){
$(this).autocomplete(autocompleteOptions);
$(document).off('focus.autocomplete', '#myAutocomplete');
});
autocomplete is not an event rather a function that enables autocomplete functionality for a textbox.
So if you can modify the js that creates the textboxes dynamically to wrap the textbox element in as a jquery object and call autocomplete on that object.
I just noticed you edited your post with this answer. It was obvious to me so I'm posting it below for others. Thank you.
$(function()
{
$('.search').live('keyup.autocomplete', function()
{
$(this).autocomplete({ source : 'url.php' });
});
});
This works for me:
$(function()
{
$('.item_product').live('focus.autocomplete', function()
{
$(this).autocomplete("/source.php/", {
width: 550,
matchContains: true,
mustMatch: false,
selectFirst: false,
});
});
});
You can just put the autocomplete inside input live event, like this:
$('#input-element').live('input', function(){
$("#input-element").autocomplete(options);
});

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