I'm trying to figure out how to bind a javascript event to a select element in GWT, however the select element isn't being built in GWT, but comes from HTML that I'm scraping from another site (a report site from a different department). First, a bit more detail:
I'm using GWT and on load, I make an ajax call to get some HTML which includes, among other things, a report that I want to put on my page. I'm able to get the HTML and parse out the div that I'm interested in. That's easy to display on my page.
Here's where I get stuck: On the portion of the page I'm using, there's a select element which I can easily locate (it has an id), but would like to capture event if my user changes that value (I want to capture changes to the select box so I can make another ajax call to replace the report, binding to the select on that page, and starting the whole process again).
So, I'm not sure how, once I get the HTML from a remote site, how to bind an event handler to an input on that fragment, and then insert the fragment into my target div. Any advice or pointers would be greatly appreciated!
How about this:
Element domSelect = DOM.getElementById("selectId");
ListBox listBox = ListBox.wrap(domSelect);
listBox.addChangeHandler(new ChangeHandler() {
void onChange(ChangeEvent event) {
// Some stuff, like checking the selected element
// via listBox.getSelectedIndex(), etc.
}
});
You should get the general idea - wrap the <select> element in a ListBox. From there, it's just a matter of adding a ChangeHandler via the addChangeHandler method.
Related
Example: We have an employee list page, that consists of filter criteria form and employee list grid. One of the criteria you can filter by is manager. If the user wants to pick a manager to filter by, he uses the lookup control and popup window is opened, that also has filter criteria and employee list grid.
Now the problem is, that if the popup window is not an iframe, some of the popup elements will have same names and ids as the owner page. Duplicate ids cause Kendo UI to break as by default MVC wrapper generates script tags with $("#id").kendoThingie.
I have used iframe in the past, but content that does not fit in iframe window like long dropdown lists gets cut off and now IE11 especially causes various issues like https://connect.microsoft.com/IE/feedback/details/802251/script70-permission-denied-error-when-trying-to-access-old-document-from-reloaded-iframe.
What would be the best solution here? Generate unique ids for all elements on Razor pages? Modify partial page content that is retrieved by Ajax making ids unique? Something else?
It sounds like you are using a partial page as the content to a Kendo window. If this is the case then just provide your partial with a prefix like so at the top of the page.
#{
ViewData.TemplateInfo.HtmlFieldPrefix = "MyPrefix"
}
Now when you create a kendo control via the MVC wrapper like so
#(Html.Kendo().DropDownListFor(o => o.SomeProperty)
.....
)
The name attribute will be generated as "MyPrefix.SomeProperty" and the id attribute will be generated as "MyPrefix_SomeProperty". When accessing it within Jquery I like a shorter variable name so I usually do
string Prefix = ViewData.TemplateInfo.HtmlFieldPrefix
After setting the prefix. Then use
var val = $('##(Prefix)_SomeProperty').data('kendoDropDownList').value();
Note after this change. If you are posting a form from that partial you will need to add the following attribute to your model parameter on the controller method like so. So that binding happens correctly.
[HttpPost]
public ActionResult MyPartialModal([Bind(Prefix = "MyPrefix")] ModeViewModel model) {
.....
}
Now with all of that said. As long as you keep your prefixes different for each partial your control ids and names will be unique. To ensure this I usually make my prefix name be the same as my cshtml page that I am creating. You would just need to worry about JS function names. Also, note when closing a kendo window all DOM still exist. You just hide it. If this causes you the same issue you just need to be sure to clear the DOM of the modal on close. Similar to how BurnsBA mentioned. Note because of this is the reason why I try to make sure I use the least amount of kendo windows as possible and just reuse them via the refresh function pointing to a different URL.
$('#my-window').data('kendoWindow').refresh({
url: someUrlString
, data: {
someId: '#Model.MyId'
}
}).open().center();
Then on the modal page itself. When posting I do the following assuming nothing complicated needs to happen when posting.
var form = $('#my-form'); //Probably want this to be unique. What I do is provide a GUID on the view model
$('#my-window').data('kendoWindow').refresh({
url: form.attr('action')
, data: form.serialize()
, type: 'POST'
}).open().center();
We do something similar, and have the same problem. We have create/edit/delete popups that fetch data via ajax. Different viewmodels might reference the same model on the same page, and if you open multiple popups (create item type 1, create item type 2) then the second and subsequent popups can be broken (kendo ui error such that a dropdown is now just a plain textbox). Our solution is to delete all dom entries when the popup is closed so there are no conflicts between ids in different popups. We use bootstrap, so it looks like
<script type="text/javascript">
$('body').on(
// hook close even on bootstrap popup
'hidden.bs.modal', '.modal',
function () {
$(this).removeData('bs.modal');
$(this).find('.modal-content').html(''); // clear dom in popup
});
</script>
Note that our popup has some outer html elements and identifiers, but the content is all in
<div class="modal-content"> ... </div>
I've already asked a similar question, but I really can't figure out how to connect these elements together. I'm still not very good with Handlers, and I guess my question is:
How can I access UI Widgets (and their children) while outside of the doGet() function?
My use case is this: I have a list of projects/IDs. I have all the data I want based on the ID that will populate the Project Details tab of this application. I created 'unique' Buttons for each of these Projects, and threw them into a Grid. Now, I want to generate the Project Details (detailPanel) Widgets specifically for each Button if/when it is clicked.
I have the Project ID attached to each Button (uniquely) through a Hidden, but I can't seem to attach the Project Details tab (detailPanel) to the Button so that, when clicked, I can set the values for the TextBox, DateBox, ListBox, etc. Widgets of the detailPanel.
I think I'm missing something obvious about this. I want to avoid attaching each child Widget of the detailPanel as a callbackElement of the Button at all costs. There are around 40 elements (I've lost count), and it seems really inefficient. I'm almost sure that if I can add one Widget as a callback element, that I get access to all child Widgets. But I tried, and that doesn't seem to be the case.
Here is the link to the public UiApp, which shows the UI. And the sister Script Project (uneditable).
You dont need to add callback elements that you will write to, callback elements are only for reading their data. If the detailspanel id is dynamic have a hidden that has its id stored inside and pass it to the handler. from your handler you getelementbyid and set its data.
I have a basic ASP.Net MVC 3 application which has a number of controllers and a number of actions (and subsequently views)
A common feature of the application is to show a pop-up dialog window for basic user input. One of the key features of this dialog process is a faded mask that gets shown behind the dialog box.
Each of these dialog window controls is in a separate Partial View page.
Now, some view pages may use multiple dialog boxes, and therefore include multiple partial views in them - which as is would mean multiple instances of the "mask" element.
What I am trying to find a solution for is to only need to create one instance of a "mask" element regardless of the number of dialog partial views I include, and then the script in each partial dialog will have access to this element (so basically it just needs to be on the page somewhere)
The only real idea I have come up with so far is to add the "mask" element to the master page (or in the original view page) and this will mean it only gets added once. The problem here is that it will be added even when it is not needed (albeit one small single element)
I can live with this, but I would like to know if there is a better way to handle these kinds of scenarios?
A quick idea that came to mind is some kind of master page inheritance hierarchy, So I may have a DialogMasterPage that inherits from the standard current master page. How does that sound for an approach?
Thanks
To do something like this, where each module can register their need for a certain thing in the master page, you can use HttpContext to store a flag of whether you need to write the mask div, and just set that property in each partial. At the end of the master page, if the flag is set, you can then write the mask div if its set to true.
Obviously to make this cleaner you could wrap it all in an HtmlHelper extension or something.
My initial thought is for you to use something like jQuery UI where it handles the masking for you or if you are using something custom you can load the content for the dialog via ajax then show it in the single dialog on the master page.
I have a web page consisting of a dropdown menu. What i want is the contents of other dropdown menus present in the page must change according to what has been selected in the first dropdown box. For example if a dropdown consists of Degree as its element. If i select Degree element then another dropdown must show only degree courses. This must happen automatically without clicking any button. How can i achieve this?
I would make this a comment, but I do not have commenting abilities. You are going to want to use $.post with jquery and ajax to accomplish this: http://api.jquery.com/jQuery.post/ . Ajax with JQuery is not difficult to do.
You will want to use the onchange event of the first drop down to use a jquery ajax $.post call to post to the server, passing the selection from the drop down as a parameter. The page that it post's to should us GET to get the selected attribute from the drop down, and then retrieve ( from the database or where ever) the options that go into the second drop down, based on the parameter. The code should be written out to the page. The jquery ajax call has a way to get the response and let you define a custom function to be run once the post returns. The return should be what you had written out to the page, and then you can just update the second drop down list with the returned data inside this function.
I hope this helps!
I'm wracking my brain on this one.
After an HTML document loads in a browser, I want to be able to monitor
the page in case any content on it changes for any reason.
Is there a Javascript function with which I can track 'what has
changed' on the webpage. This should be irrespective of the type of content on the HTML page.
I have two examples for you to ponder on:
Ex1:
Say in an HTML document there are two select boxes s1 and s2.
The items list in s2 depends on selections in s1 (page is not
refreshed — that is, s2 is loaded through Ajax or something).
So after the HTML page loads I need to get a notification whenever s2
is populated...
Ex2:
Say, in an HTML page, there's a link, Onclicking which a light pop-up
div is created with some text.
How can I capture the content of this dynamic pop-up?
In all this discussion, I'm not taking into account any particular
format of HTML...the HTML content can be anything...I just need
to keep tracking if any content changes after the page loads...
Ideally I need to achieve this using JavaScript (client-side
scripting).
How can I achieve this?
You can keep track of changes in a textbox using onkeyup. This will tell you every time someone makes a change in a given textbox.
This could potentially fire alot of events. However, using onblur won't necessarily tell you about changes in the textbox and onchange's browser coverage is spotty at best.
If you are using AJAX, you could setup the response function to handle a home grown "event listening" system. So after the response does what it needs to do, it could call any methods that were registered with it, passing in the response text when necessary.
So from your examples above, in Ex1, when the AJAX returns from S1, it would load S2, then call a method saying S2 had changed. In Ex2, when the new AJAX returns the DIV's contents, after loading it into the DIV, it call a different method (or possibly the same depending on what your trying to do) and alerts it that the DIV has new contents.
You could set your "watcher" script as a timer, running a diff function on the current document.body.innerHTML and a stored version captured on load. Depending on how fast the diff will run will give you an idea on what timer interval to use.
This may not capture changes in form elements, but for those, it's easier to loop through all form elements in every form on the page.
Here's someone's diff function I found on Google: http://snowtide.com/jsdifflib