I am developing a website using mainly AJAX for saving and retrieving data in order to avoid postbacks (or at least full postbacks).
I "prepare" the page in codebehind, and on client I use JQ and Javascript.
When I want to save data I serialize the elements in a container (using JQ) and then AJAX post to send data to the WebMethod.
This is working well but I have to deal with long name elements ("ctl00$MainContent$grdEmployees$ctl03$ddlRole").
Sometimes is difficult to retrive data from the NameValueColletion as the same WebMethod can be called from different pages, so the "name" of the element is not the same as the control may be nested in other container.
Is there a way to set custom names for ASP.NET controls to avoid this issue?
Or other way to achieve this behavior?
Best regards.
Have you tried to use ClientIDMode="Static" which is found in .NET 4.5.
When a page is render the ids all change as you have noted. However, you set the ClientIDMode to static it will render with the ID that you have put for the control itself. That way you can work with the ID of the control instead of the generated id. If you would like to know more here is a like to the MSDNA about ClientIDMode
http://msdn.microsoft.com/en-us/library/system.web.ui.control.clientidmode(v=vs.110).aspx
In ASP.NET much has been made about the ClientIdMode property that gives developers greater control over the a control's ID attribute as it appears in the HTML.
However little attention appears to have be paid to the way the controls render their Name attribute. It appears to be a simple concatenation of the control's ID and its hierarchy of naming containers.
Given a sufficiently complex web page these names get very long. They not only make the HTML payload big (and ugly) but are also posted back to the server on every postback. (Also, they make their way into the Control State of some third party control suites. )
Why isn't there a ClientNameMode property - or similar? Surely it is as important as the Id attribute? Is it possible to override some method that generates / rehydrates the Name attribute so that we can man handle it to maybe match the Id? (made shorter by the ClientIdMode)
An example of a name of a control on a page that I am working on is
USoWAR1_tabContainer_UDetailsTabContainer_tabContainer_UDetailsTab_UDetails1_UDueDateAndNotifications1_decDetail_DataEntryRow1_datDueDate_DateTimePicker_calendar_AD
As far as I know the only way to alter this functionality is to extend controls into your own and override UniqueID property (e.g. by returning Server-side ID).
I had this same issue, and had to use JS to set the attr after loading.
$('#idofdomobjiwanttoname').attr("name", "whatIWantToNameIt");
Does the ASP.NET ClientServerManager provide some method or property to return the name of an ASP.NET control in the generated html page that could be used to write the javascript (using RegisterClientScriptBlock) in the code-behind? The actual generated control names can be quite long and unknown (I am also using master pages). I would like a generic way to write the javascript text and have the actual names of the controls be added to the javascript string. I would expect some method that I pass in the name of the control and it returns the actual html control name. I have searched in the documentation of the ClientServerManager and could not find anything.
Control.ClientID is rendered as html tag ID, so you can use that property.
If you are worried about control names, check out ClientIdMode where you can specify this and make it much simpler.
http://msdn.microsoft.com/en-us/library/system.web.ui.control.clientidmode.aspx
Would this help your issue?
This I can't work out
I have ASP.Net user control,which is basically two drop downs, that has a public property Index which is calculated from the drop downs, and works fine
I need to access the value of 'Index' from javascript, but accessing via getElementById was completely wrong, can anybody point me in a better direction
Cheers
The property you're talking about is a server side thing and has no presence in Javascript. Basically, whatever ASP.NET does on the server will generate a single HTML page containing a bunch of HTML tags. The browser is not aware of the user control being a single entity at all.
You should calculate the property on the client by looking up the ID of the drop down directly in Javascript. You can do find out the client ID of the drop down by getting its ClientID property.
Create javascript method as a string from server side and use index property to create script string.
register string on which event it is required.
you can take help from following link to register javascript:
http://msdn.microsoft.com/en-us/library/aa479011.aspx
If any server side control is used in javascript method, use ClientID property as ID of the control.
Hope, It helps
Im adding textboxes (not a fixed number of textboxes) dynamically to a form on ASP.NET page, how do i read back data from these textboxes?
Assuming you're wanting to access the controls on the postback you'd probably re-create the dynamic controls exactly as they were created on the initial load, then use the page's FindControls method to find the controls. It would probably help to create the textboxes with IDs like Textbox1, Textbox2, etc.
Look at Request.Params and extract them from there. You will, of course, have to give them ids to be able to tell them apart.
From all the ASP.NET apps I've worked with, .NET likes to use the following algorithm when generating the Id for server controls:
ctl00$cphBody$[ControlID]
Try using this algorithm when accessing your data from the dynamically generated textboxes.
When you add them you should be giving them names/ids, and you can use those to reference them.
If not, walk your DOM in javascript to find them inside the form you made - they'll be in the same order you inserted them.
Lastly, they're all available as post/get inputs to your page, so you should be able to look at them all as long as you assigned them different names.
-Adam
When creating textboxes dynamically (presumably using JavaScript, but same goes for ASP.NET controls) give them names in a specific pattern. The one you will be able to recognize later.
On server-side, in any event handler occurring after Page_Init you can iterate through Request.Form collection.
Do not be tempted to use Request.Param because it can be used to apply cross-site request forgery on your application (an attacker could lure user into issuing a GET request which your application would interpret the same as it would interpret a POST one, which is usually not a good thing).
If you are adding dynamic ASP.NET controls (in Page_Render for example) you can also reconstruct controls and use their properties.
You can use FindControl and pass the textbox ID to get an instance of the textbox when post back. The Text property contains the data, given that we are at page load stage or later in the cycle.
When adding dynamic controls, override the CreateChildControls method and add the dynamic controls to control hierarchy at this stage of the cycle.
Remember that in ASP.Net, every postback is a new instance of your class. If you created these controls during a previous postback or on the first view then they were garbage collected with the rest of that previous instance. So to use the controls in this new instance, you need to create them again. If you need the state information loaded for those controls (including any value entered by the user), you also need to create before the viewstate is loaded, meaning you do it during the Init event, rather than the load event.
To create dynamic controls, I would usually use a ASP.NET PlaceHolder Control and add the dynamic controls to this container.
I would give each dynamic control an ID.
You can then subsequently use FindControl on the PlaceHolder to access the dynamic controls.
I say "dynamic controls" to mean controls you add at run-time