Currently I use this to check if a tab(element) already exists:
if(!$('#'+element).length){
//... code to add new tab if not exists.
} else {
Alert("Tab or portlet already exists...");
}
This is very dirty and I get a "uncaught exception: Syntax error, unrecognized expression: #" from FireBug. If element already exists, the "Alert" doesn't show, I think it hangs at the first exception.
Is there a better way to check if an element exists? (Or a tab)
I am using this for my personal project # http://www.soliman.nl/test/jqueryui/ui_2.php
The problem seems to be in your source - you are passing "#foo" as the parameter element, then prepending another "#". The result is $("##foo"), which just isn't going to work.
please check value of element
coz if this is null or empty your statement become
if(!$('#').length){
or
if(!$('#null').length){
which may through some error
here is working version
<html>
<body>
<p id="test"></p>
</body>
</html>
var element = "test"; //if you try to comment this line or change value , it will give error
if(!$('#'+element).length){
alert("do something");
} else {
alert("Tab or portlet already exists...");
}
Demo
http://jsfiddle.net/J3MdK/
Related
I have been scouring the web for a clear answer on how to query for an element generated by a dom-repeat element from Dart code.
sample.html
<dom-module id="so-sample>
<style>...</style>
<template>
<template is="dom-repeat" items="[[cars]] as="car>
...
<paper-button on-click="buttonClicked">Button</paper-button>
<paper-dialog id="dialog">
<h2>Title</h2>
</paper-dialog>
</template>
</template>
sample.dart
I'll omit the boilerplate code here, such as imports or the query to my database to fill the cars property ; everything works fine.
...
#reflectable
void buttonClicked(e, [_])
{
PaperDialog infos = this.shadowRoot.querySelector("#dialog");
infos.open();
}
This generates the following error :
Uncaught TypeError: Cannot read property 'querySelector' of undefined
I have tried several 'solutions', which are not, since nothing works.
The only thing I saw on quite a lot of threads is to use Timer.run() and write my code in the callback, but that seems like a hack. Why would I need a timer ?
I understand my problem may be that the content of the dom-repeat is generated lazily, and I query the items 'before' they are added to the local DOM.
Another advice I didn't follow is to use Mutation Observers. I read in the polymer API documentation that the observeNodes method should be used instead, as it internally uses MO to handle indexing the elements, but it again seems a bit complicated just to open a dialog.
My final objective is to bind the button of each generated model to a dedicated paper-dialog to display additional information on the item.
Has anyone ever done that ? (I should hope so :p)
Thanks for your time !
Update 1:
After reading Gunter's advices, although none of them actually worked by themselves, the fact that the IDs aren't mangled inside a dom-repeat made me think and query paper-dialog instead of the id itself, and now my dialog pops up !
sample.dart:
PaperDialog infos = Polymer.dom(root).querySelector("paper-dialog");
infos.open();
I now hope that each button will call the associated dialog, since I'll bind data inside the dialog relative to the item I clicked ~
Update 2:
So, nope, the data binding didn't work as expected: All buttons were bound to the item at index 0, just as I feared. I tried several ways to query the correct paper-dialog but nothing worked. The only 'workaround' I found is to query all the paper-dialog into a list and then get the 'index-th' element from that list.
#reflectable
void buttonClicked(e, [_])
{
var model = new DomRepeatModel.fromEvent(e);
List<PaperDialog> dialogs = Polymer.dom(this.root).querySelectorAll("paper-dialog");
dialogs[model.index].open();
}
This code definitely works, but it feels kind of a waste of resources to get all the elements when you really only need one and you already know which one.
So yeah, my initial problem is solved, but I still wonder why I couldn't query the dialogs from their id:
...
<paper-dialog id="dialog-[[index]]">
...
</paper-dialog>
#reflectable
void buttonClicked(e, [_])
{
var model = new DomRepeatModel.fromEvent(e);
PaperDialog dialog = Polymer.dom(this.root).querySelector("dialog-${model.index}");
dialog.open();
}
With this code, dialog is always null, although I can find those dialogs, correctly id-ied, in the DOM tree.
You need to use Polymers DOM API with shady DOM (default). If you enable shadow DOM your code would probably work as well.
PaperDialog infos = new Polymer.dom(this).querySelector("#dialog")
TableElement table = new TableElement();
document.body.children.add(table);
table.children.add(new Element.html("<tr><td>test</td></tr>"));
The above code snippet returns the error: "Uncaught Bad state: No element". Reading the API docs on the DartLang website this is because when using the Element.html(" ") constructor, "the HTML fragment is parsed as if it occurred within the context of a <body> tag". Therefore, we would need to write:
new Element.html("<table><tr><td>test</td></tr></table>")
However, reading "dart in action" Chris Buckett uses this exact same syntax when building a table.
Has something changed or am I misunderstanding something?
This is a browser "feature". A <tr> element can't exist on its own and is just dropped from the HTML when it finds one.
The docs to new Element.html() says
Creates an HTML element from a valid fragment of HTML.
Alternatively you can use
table.append(
new TableRowElement()..append(new TableCellElement()..text = 'test'));
DartPad example
I am currently using Select2 in a project and would like to add a option to my select list that shows up regardless of what the user types or searches. The idea is to have a "Add new" option always present in the list.
I do not think my code is necessary here (but if needed I may provide) as the only thing i'm lacking knowledge in this specific topic is on how to keed the option always showing.
I thought of using the matcher attribute, but i'm not sure how.
I've managed to do it setting a new matcher, the problem was I was not sure on how to create a new matcher and still use the select2 default one.
Something else I was missing was the full version of select2.
function newMatcher(term, text){
//The "ADD NEW" String is the text in the option I want to always show up.
//The code after OR looks for the actual results for the user's search
if ((text.toUpperCase().indexOf("ADD NEW") > -1)
|| (text.toUpperCase().indexOf(term.toUpperCase()) > -1)) {
return true;
}
}
$(document).ready(function() {
$.fn.select2.amd.require(['select2/compat/matcher'], function (oldMatcher) {
$('select').select2({
matcher: oldMatcher(newMatcher)
})
})
});
Hi I have a working FilteringSelect which reads from a URL. Entering names will query the database and return the appropriate JSON to populate the filtering select, I can select a value and it stores the ID.
<div data-dojo-type="ComboBoxReadStore" data-dojo-id="assignedUserIdstore"
data-dojo-props="url:'Welcome.do?call=JS&actionRefId=142',
requestMethod:'get'"></div>
<input id='assignedUserId' name='value(assignedUserId)'
data-dojo-type='dijit.form.FilteringSelect'
data-dojo-props="store:assignedUserIdstore, pageSize:5, labelAttr:
'label',queryExpr: '*${0}*', autoComplete: false" />
The issue comes with setting the default value. I have this
<script type='text/javascript'>dojo.ready(function(
{dijit.byId('assignedUserId').setValue('25');});
</script>
This appears to work after a fashion - it does call the server and the server returns this
{ "id":"25", "name":"John Smith" "label":"John Smith"}
However it does nothing to actually populate the filtering select with neither a display nor an actual value for the input. I tried to set the value to the name but that had no effect either. Having it return a collection instead of a single item does not help either.
The comboreadstore is defined as
<script type="text/javascript">
require([
"dojo/_base/declare",
"dojox/data/QueryReadStore",
"dojo/parser",
"dijit/form/FilteringSelect"],
function(declare, QueryReadStore){
declare("ComboBoxReadStore", QueryReadStore, {
fetch:function(request) {
// This results in a xhr request to the following URL (in case of GET):
// /url.php?q=<searchString>
request.serverQuery = {q:request.query.name};
return this.inherited("fetch", arguments);
}
});
}
);
</script>
Using dojo.ready doesn't guarantee that the data you're fetching is ready/loaded. It does fire when dojo is ready and all your required assets have been loaded. So i think you're trying to set the FilteringSelect to a value which doesn't exist in the store yet. You could solve this by waiting with setting the value untill the store is ready. How to do that depends on the store you are using which i can't really make up out of your code. I'm not familiar with ComboBoxReadStore. After some googling i found out it might be an extension of dojox.data.QueryReadStore, which is outdated and unfinished. If so i'de suggest you switch to using dojo.store if possible.
Furthermore: The setValue method on dijits is deprecated, you should be using set('key', val).
I have a JQM apps and I am incorporating Backbone.
Since my initial javascript code is huge, I am only extracting what I believe is problematic.
I am following the advices and calls steps cited here:
jqm-config.js from http://coenraets.org/blog/2012/03/using-backbone-js-with-jquery-mobile/
http://jquerymobile.com/test/docs/pages/backbone-require.html
I have a major problem, and this is the behaviour, the problem comes from this code:
var r = Backbone.Router.extend
router: ...
"page": "pageDisplay"
...
pageDisplay: function(){
c = new AView(); // Backbone.View ...fetch() data...
$(c.el).page(); // Call to JQM to add its extra stuff; seems done correctly
$.mobile.changePage( "#" + c.id, {changeHash: false}); // line 50
}
When following the links of <a href="#page" >, I come as expected to the
page "#page" properly processed. But once there, if I click a refresh, which is indirectly reprocessed by the same router rule, I end up with the following error:
Uncaught TypeError: Cannot call method 'trigger' of undefined
I downloaded the jquery mobile development code and observed this:
// JQM1.1.2 - Line #3772 Show a specific page in the page container.
$.mobile.changePage = function( toPage, options ) {
if ( isPageTransitioning ) {
pageTransitionQueue.unshift(arguments );
return;
}
var settings = $.extend( {}, $.mobile.changePage.defaults, options);
// Make sure we have a pageContainer to work with.
settings.pageContainer = settings.pageContainer || $.mobile.pageContainer;
// Make sure we have a fromPage.
settings.fromPage = settings.fromPage || $.mobile.activePage;
// Line #3788
var mpc = settings.pageContainer, // Line #3789
pbcEvent = new $.Event("pagebeforechange" ),
triggerData = { toPage: toPage, options: settings };
// Let listeners know we're about to change the current page.
mpc.trigger( pbcEvent, triggerData ); // Line #3794
The Uncaught TypeError is caused by Line #3794, because mpc is undefined.
So, from JQM, In the Chrome inspector, I can see also that settings.fromPage is undefined and settings.pageContainer is undefined. I kind of imagine, that JQM cannot make an assumption on the fromPage, and therefore, cannot proceed on my refresh. All the options I have tried on the $mobile.changePage() have not succeed. I am out of ideas.
UPDATE/ Online site with the minimum to reproduce the problem:
apartindex, access the website with the bug
Any help will be appreciated.
The dextoInit function that calls the router code is called in $(document).ready() which does not guarantee that the jQuery mobile page has actually been set up successfully. But the router code calls $.mobile.changePage which depends on jQuery Mobile being initialized.
Putting it into mobileinit or pageinit should work.
(Unfortunately I can't modify the code and test it easily.)
Although, this fix it for the moment, it does have drawbacks. See below.
$(document).bind("pageinit", function(){
console.log('bindtomobileinit: event pageinit received');
if ( !window.AppNode.router ){
window.AppNode.router = new AppNode.singletons.router();
console.log("mobileRouter.js: Starting b history");
console.log('mobileRouter.js: About to launch Backbone history');
Backbone.history.start();
}
});
Registering to pageinit has a weird effect of being fired twice. I see that 2 nodes have been added to the Dom: the default "loading" jquery mobile div (related to pageinit:1), and my data-role page (pageinit:2). So on a "refresh browser click", my situation leaves me waiting for a first pageinit, creating an unexpected jquery mobile dom element (a default page created to display the waiting JQM circle animation), which trigger the router creation, and allows the Backbone.history call which then deal with my "" home page. The second pageinit do not interfere with the settings since I execute it only once.
I am really disappointed by this setup. I will leave this question for now, since it does sort of work.
I've found the source of the problem to be jquery-mobile version 1.3.0. When I fall back to either JSM 1.2.0 or 1.2.1, the "Uncaught TypeError: Cannot call method 'trigger' of undefined" problem goes away.
BTW, I am not using Backbone.
I had fixed this problem by using method append(), but not html()
$('body').append(view.render().$el);
I was able to resolve this issue by changing the page data property from "data-role" to "data-mobile-page" as what is referenced in line 4042 of jqm 1.3.2
fromPage.data( "mobile-page" )._trigger( "beforehide", null, { nextPage: toPage } );
Setting
$.mobile.autoInitializePage = true;
In your jquery mobile config file, some place like:
$(document).on("mobileinit", function () {...});
May help.