Hi
I need to validate two fields in an Asp.net form, where the requirements is like any one of them is required. For example, there is Page title and sub-heading input boxes, so any one of them is required. Can I do it using the validation controls Asp.Net provides?
Any kind of help is greatly appreciated. Thanks in advance.
You can use a CustomValidator control (MSDN) in ASP.NET for special situations that are not supported by any one of the other standard validators. It was created for this reason.
Microsoft describes how to create a custom validation function here.
Here's another tutorial on implementing it.
Or if you google for keywords like "creating a custom validator in asp.net" you can pick and choose from various solutions for your own project.
For your case, as an alternative to using a CustomValidator, you could explicitly change whether your required field validators are enabled by using the ValidatorEnable() JavaScript function.
// disable validation control
ValidatorEnable(RequiredFieldValidator1, false);
You can then write custom logic in JavaScript to determine the case in which each validation control is either enabled or disabled, and tie it to one of the (client-side) events of the text boxes (onblur, onchange, onkeyup, etc).
Then, on the server side you can write similar logic to do the same thing by setting the "Enabled" property and put this logic in your button click event before you check the IsValid state.
If all you are doing is conditionally determining when something is required, changing the enabled state is your best bet. Exactly what can be done is documented in ASP.NET Validation In Depth.
Related
I want to use ASP.NET's native validation inside my ASPxGridView's edit form template. I do not want to use DevEx's validation, but instead have standard ASP.NET validators in the edit form that report to a validation summary within the template. Can anyone point me in the right direction with this? Thanks.
Have a look at this in Devexpress' forum:
http://community.devexpress.com/forums/p/67285/228991.aspx
According to this, "Standard ASP.NET validators do not support callbacks. Fortunately, controls of the ASPxEditors suite have their own validation mechanism." So it seems like the standard ASP.NET validators will not work.
By default, the DevExpress ASPxGridView control works via AJAX callbacks.
Standard ASP.NET validators do not work properly inside callback-based containers:
http://www.aspnettricks.com/archives/validators-inside-update-panel-doesnt-work-properly/
http://www.devexpress.com/issue=Q274114
It is possible to switch the ASPxGridView control to a standard postback mode.
Just set the ASPxGridView.EnableCallBack http://documentation.devexpress.com/#AspNet/DevExpressWebASPxGridViewASPxGridView_EnableCallBackstopic property to “false”.
However, (I think) it is better to use built-in DevExpress ASPxEditors validation. You can always get assistance from the DX team.
I have a website in ASP.NET (WebForms, NOT MVC) which has a survey form divided in several slides. Each slide has a next button that, obviously does a transition (client-side, not post back or remote request) to the next slide.
In each slide I have several ASP.NET controls with their related validators. I want this validators to be triggered when I click the next button (or maybe when each input loses focus?).
I remembered ASP.NET doing client side validation on lost focus, but maybe I'm wrong... (I quit doing ASP.NET development about 3 years now, so I can't remember)
Thanks
UPDATE:
It would be better to make ASP.NET trigger each validator when the associated control lost focus. I remember ASP.NET doing this (or am I dreaming? =P)
First you need to make sure all of your validators have target controls specified using the "TargetControlID" Attribute on the validators.
Then you can set up a validation group per page and specify the group name in your next button and on the controls themselves.
If you are using regular expression validators you can choose them from this website
To Validate Client Side
If you are using custom validators you can create a client function and specify it on the custom validator using the ClientValidationFunction attribute and by setting EnableclientScript = "true" on the custom validator.
Just be sure your client function has sender and args parameters.
It looks like there's a supplied JavaScript function called Page_ClientValidate which should be callable to check the validation manually from JavaScript. I haven't used it, though, so YMMV.
put all your client-side validators into the same validationgroup and with your 'next' button add the same validation group. When you click the button it will automatically trigger all the validators before it does the post-back.
as to manually triggering the validation...
you might also be able to use ValidatorOnSubmit(). I remember doing this in another project but i'm having a hard time finding the code.
It seems that enabling 'SetFocusOnError' on each validator triggers the validation whenever I try to leave the field.
In short decorate your model, now Data Annotations are supported from Asp.Net 4.5
Check my Answer here..Client side webform validations
ASP.NET has a number of nice features regarding making data input pages:
Adding input controls is easy (<asp:...).
The system automatically generates member variable for the controls.
Post-backs automatically populate the members variable with the returned values.
and some not so nice bits
post-backs seem to be tied to JavaScript for even the simplest of cases. For instance, with statically defined pages, using only basic controls, that are known at compile time.
My questions:
Is is possible to get the first list without the second?
What features does that JavaScript give the user?
What does that JavaScript actually do?
What is the technical reasons that it's used even in trivial cases?
As it happens my assumption were in error: See here
It really depends on the types of controls you are trying to use here -- the only ones that implement javascript are those that can't natively cause a postback (ie, an input/submit button are the only two that can). If you are using a LinkButton, ImageButton, or anything that you set "AutoPostBack = true" on will turn javascript on in order to cause a postback.
Other controls can also potentially use javascript if they are more advanced such as the Calendar. The technical reason for using javascript here is to provide automated postback when the controls require more advanced server interaction -- think about it, a link is meant to only ever be a link and if we're trying to make it operate as a button we have to force it to do just that through javascript interaction.
So that being said, yes you can definitely use ASP.NET without it having javascript you just have to avoid the controls that implement it by including functionality you couldn't possibly have without it. You can just as easily add HTML controls and add the runat="server" attribute and gain member variables to the control from code-behind.
Here's what came to my mind:
What features does that JavaScript give the user?
Client side validation.
What does that JavaScript actually do?
For exmaple, it ensures that the correct (server-side) event handlers are called, by setting the __EVENTTARGET hidden field.
Is is possible to get the first list without the second?
You can use normal HTML controls instead of the ASP.NET controls. Then on the server-side, you can read the control's values from the Form collection.
I assume you mean the javascript associated with an <asp:Button /> control, right?
In addition to the reasons mentioned by Fooberichu, the javascript can also help with ASP.NETs client side validation framework.
But I think it's primary use is to alert the framework what events it should fire on the postback in the page behind.
So if you had two buttons on the form, SaveButton and DeleteButton, the javascript helps the framework know whether it should execute the SaveButton_Click event or DeleteButton_Click event.
Hope this helps.
I'm using various ASP.NET controls out of the box such as the CreateUserWizard control, Login control etc... For custom controls, I have sanitized my inputs by making sure they conform to expected values. However, is this required for the controls such as the CreateUserWizard control, or is that handled internally? Do I need to provide any extra server side validation to these controls and, if so, would it be best to do it in the "CreateUserWizardControl_CreatingUser" event?
Thanks
If input is coming from any form, then treat it as suspect. I've included some links here that may help you:
http://www.codersbarn.com/post/2008/11/01/ASPNET-Data-Input-Validation.aspx
If you have request validation enabled then form data with script tags will generate an error automatically.
I have a requirement wherein I have a bunch of about 10 aspx pages.The user shall be able to go from one screen to another using navigation.All the range , custom,regex validators need to file so that data enetered is correct.Required fields need not be entered at this stage and the user can skip required fields. On the last page, I need to find out all the fields which are required and if incomplete want to show the user, these fields are required, sort of summary with link to the page where the control was left blank.
Does any one have any good ideas to achive validation on pages which the user has left and can do validation at the very end before the data is submitted. Any pointers would be greatly appreciated.
Validators form part of the page on which they lie. You cannot use the built-in validator controls to validate input fields on previous pages in the sequence. If you must do it this way, then you should implement your own validation framework which validates data on each page, but provides feedback on the summary page.
You should look into the usability issues faced if you only give feedback to the user at the end of the sequence of pages. He/she will be required to go back a few pages and retry input there. I don't think that is a good option at all.
A much better option would be to use the ASP.NET Wizard control (which loads sequential UI in separate panels, but on the same page). That would enable you to use Validators in conjunction with your setup. This article by Steve C. Orr provides a good introduction to using Validators with the Wizard control.
Alternatively, you can use the AJAX Tab control as others have suggested.
You can achieve this by using i.e. a TabControl (ships with the Ajax Control Toolkit).
Same thing I am applying in Asp.net MVC but I suggest you to use Tab control rather to use Bunch of pages as sshow posted.