I have a Flex 3 app with a view in a viewstack, and that view must only be created when requested. I have declared validators for each of the controls on the view and I have created a method called checkAllValid() which runs Validator.validateAll(). This works great when I'm actually using the controls (using the change or focusOut events), but how can I get checkAllValid() to run when the view is first displayed to the user, so that they are immediately shown what is invalid once the data is populated in the controls?
I have tried putting the call in various events on the view itself (e.g. creationComplete, updateComplete, show, activate, etc.) but it always shows the following error when I start the application:
'The source attribute must be specified when the property attribute is specified.'
I have also tried setting the creationPolicy on the view to "all" but this does not help.
Some of the validators are only enabled when the form is in a certain state, but I have eliminated that as being the potential problem by commenting out all of my validators except for this most simple one:
<mx:Array id="validators"><mx:StringValidator id="val_Address1" source="{Address1}" property="text" required="true" triggerEvent=""/></mx:Array>
The checkAllValid() method is as simple as follows:
private function checkAllValid():void{
var validationErrors: Array = Validator.validateAll(validators);
}
I have also tried calling the single validator directly rather than using validateAll and the result is the same.
Please help! There must be a way I can force the view to validate when it is shown....
(by the way it's in the Cairngorm MVC framework and I have data bound to the controls)
Got it! I added similar validators to another view and they worked fine. What was the difference? The method that called checkAllValid() was being called on the creationComplete event of an internal container - not the main view component.
So in the end it was nothing to do with the validation itself - just me not fully understanding the creation order.
I'll leave the question on here just in case someone encounters a similar problem with the creation order.
Related
Recently, I discovered that using: someControl.Attributes.Add("customAttr", "customVal") is not compatible with all web browsers. The recommended registration for custom attributes is:
Page.ClientScript.RegisterExpandoAttribute(someControl.ClientID, "customAttr", "customVal")
Okay, here's the problem. I am using a ListView to generate a custom control. In certain scenarios, the ListView must be refreshed/recreated. When this happens, and a ListView item attempts the register (in this case, re-register) the expando attribute, the page throws the following error:
An entry with the same key already exists.
Obviously RegisterExpandoAttribute() does not behave like the Page.Cache object where if a key already exists, the current value is overwritten. I can easily hack my way past this problem but I wonder if there is a more elegant solution to this. For example, there is no method like: Page.ClientScript.IsExpandoAttributeRegistered(...)
Any ideas?
If you're creating a custom control, try doing the RegisterExpandoAttribute call during the control PreRender. I was having issues with the attribute still being registered if the control had been removed and doing that fixed my issue. I would imagine that if you're calling RegisterExpandoAttribute in the PreRender for the control then it shouldn't be called more than once per page load.
I have a drop down in an ASP.NET page. Whenever the value of the drop down changes an ASP.NET AJAX request is made to the server. I also attached a jQuery "change" event handler to that list to execute some code when the value is changed. So, probably two different event handlers are being attached to the same drop down, and it's causing some problems, i.e., sometimes wrong drop down values are sent to the server. I don't know why is this happening but I think attaching two different event handlers to a same drop down may be the reason.
Can anyone tell me what is the problem here? If what I guessed is true, then is there any other way to execute some custom javascript code before asp.net AJAX request is sent ?
Normally the JQuery change() binder respects all previous binds (won't break them). If you want to be sure the methods are called in the correct order, bind ONE master method to the change event, and have that one method call both methods (the qsp and the jquery) in the right order :)
I have a custom class (ServerSideValidator.vb) that validates user input on server side (it doesn't use any of the .NET built in validators, therefore Page.Validate() is not an option for me). I am calling the Validate() method on page.IsPostback event and the class performs without any problem
My issue is, when validation fails (returns false), I want to stop the postback event handler from firing, but load the page along with all the controls and user-input values in them. If I do, Response.End(), the page comes up blank. I can programmatically instruct the page to go to the previous page (original form before postback), but it loses all user-inputs.
I thought of creating a global boolean variable in the page code behind file and check the value before performing any postback method, but this approach takes away from my plan to provide all functionalities inside the class itself. The page object is being referenced to ServerSideValidator.
Seems like all the postback related properties/variables I come across inside Page class are 'Readonly' and I can't assign value(s) to control/prevent postback event from firing.
Any idiea on how I can accomplish this? Please let me know if you need further details
It's probably easier to post back to the same page every time and do your validation there, specifically on the page load event. If the validation fails, you're already on the correct page and don't have to go to a previous page. If the validation succeeds, then you can redirect to another page if you wish, in which case you probably don't need any data.
Edit: This isn't exactly what you asked for, but I have a feeling it will do what you want while fitting into the existing ASP.NET validation design. See http://www.dotnetcurry.com/ShowArticle.aspx?ID=197 and https://web.archive.org/web/20211020145934/https://www.4guysfromrolla.com/articles/073102-1.aspx
Basically, you create a custom class just like you have now, but inherit from BaseValidator. To follow your design, you can create an enum called ValidationType which has Alphabetic, Alphanumeric, etc. In your custom class, create a property called ValidationType that uses the ValidationType enum. Of course you have to add all the validation logic. Then in your aspx page, you can add your custom validator to the page and set ValidationType="Alphabetic", etc. with full IntelliSense support.
Since you use BaseValidator, all the regular validation techniques will work including Page.Validate(), Page.IsValid, etc. You can even create client-side validation JavaScript if you wish.
Having said this, someone has probably already done most of this for you.
I am creating a series of client side component controls on the fly that are nested inside a update panel. The first time I create the controls, everything works as desired, however, when i trigger an update on the update panel and it does a partial postback the controls come back with several javascript errors describing how the control is already registered on the page.
I get a series of errors that say something about like:
"Error: Sys.InvalidOperationException: Two components with the same id "master_ctl40_CCB_PALETTES" can't be added to the application"
Any ideas anyone?
Try these tricks:
On Page_Load put uxFailedControl.ID = DateTime.Now.ToString(); It will ensure your control has unique ID every time page reloads (fully or partially), so theoretically you shouldn't see anymore "same id" errors.
If you display your control in Modal Popup: Every time you hide the popup from the server, remove the control from it's container (Panel, Page, Control, etc.) Use uxModalPopupPanel.Controls.Clear(); or uxModalPopupPanel.Remove(uxFailedControl);
When you are done with debugging set ScriptMode property of your ScriptManager to "Release". It will prevent internal AJAX exceptions to be bubbled up to the browser.
In which event are you adding the components to the update panel? I.e. have you placed them inside the page load event without a postback check or have you placed them inside the update panel load event? etc...
Looks like your client object is being created more than once.
If you want your client side controls to be replaced when the update panel they're in refreshes, they should inherit from Sys.UI.Control, which takes takes an element in its constructor. When that element is replaced by the update panel, the client object will be disposed and then re-created. If you're currently using a ScriptComponentDescriptor on the server side to define the client control instance, you'll want to switch to a ScriptControlDescriptor.
By the sounds of it, your client objects just inherit from Sys.Component, which will hang around until they're manually disposed, which is why you're getting an error about having more than one component with the same ID.
I would advise against using a new ID every post back - this will just keep creating new client objects without ever cleaning up the old ones.
I have asp.net form that contains fields. When I access this window, my javascript functions can access the fields via the DOM with the getElementById() method and when I postpack to the server I am receiving the updates made by the client.
However, when I launch the form as a child window using Telerik's RadWindow control, the javascript can not access the hidden fields on the child form. Instead I get null.
My questions are:
Are hidden fields on a child window
not accessible when the window is
launched from a parent asp.net form?
Has anyone attempted this with Telerik controls and run into issues?
EDIT
Craig pointed out that the id may be different. Two additional questions then:
Can you ensure that the id you assign at the server is actually used?
Is using getElementByName() a better mechanism to access DOM elements?
To get the ID of your asp.net control do something like this:
<%= theControl.ClientID %>
getElementByName is not as commonly used as getElementById. The ID attribute is supposed to be unique for each element on the page whereas the name attribute can be duplicated.
It is quite possible that the element's ID is not what you think it is. Check the rendered page and see if the ID is there. I am guessing that the page is given a different ID since it is rendered inside another control.
If that is the case, you can have the form render some script that returns the element ID by accessing the controls client ID.
David, I'm sending you this answer because I saw the same issue in my code, and the only REAL solution I found was that I had to support the "OnClick" function in two places... In my case, I was using PetersDatePackage, but it was on a Telerik RAD Strip.
In my case, the control was on a .ascx page, and the JS code was as follows:
function OnIncidentDateChange(ctrl, dtDate, bErr)
{
var weekday = new Array(7);
weekday[0] = "Sunday";
weekday[1] = "Monday";
weekday[2] = "Tuesday";
weekday[3] = "Wednesday";
weekday[4] = "Thursday";
weekday[5] = "Friday";
weekday[6] = "Saturday";
<%=LabelDayOfWeek.ClientID %>.innerText = weekday[dtDate.getDay()];
}
But, this itself was not enough. I had to add THIS code to my parent page. The page that holds the controls for the Telerik strip.
// Dummy function?
function OnIncidentDateChange()
{
}
Once I did that, it worked...
I'm not certain why, to tell you the truth, and it makes no sense to me, and may just be a issue with the PDP package...
I use getElementsByName for checkboxes within the same group.
As for the control's ID, TonyB has the right idea, but make sure you refer to the ClientID property in the PreRender event handler, because if you do it too early in the page life cycle, it will not be available yet).
Is it possible the that javascript is trying to get a reference to the hidden field before the RadWindow has loaded it? I believe I've run into this before and had to use setTimeout to get around the problem.