how to postback part of a page in ASP.NET - asp.net

I know that update panels help rendering part of a page, but what I'm asking is how to postback part of a page to server not all. I have a page that has several inside each a form that postsback some info to server. I want each submit button to postback only it's own form information not all others too.
The actual problem is that when I submit one of the forms required field of other forms won't let me do the postback. So a rephrased question might be, how do I disable validation for a button and enable it for others?

You need to use validation groups. For example:
<asp:requiredfieldvalidator
ValidationGroup=“val_grp_1”
ErrorText=“Missing Value”
ControlToValidate=“txt_firstname”
runat=“server”/>
And then on your submit button, you reference the group you want to have validated:
<asp:button
text=“Group1”
ValidationGroup=“val_grp_1”
runat=“server”/>

Related

How to prevent validation for an event handler of a user control?

I have a user control with a delete button. When a button is clicked, an event fires which deletes a record from the database. Now, the control is placed in Default.aspx. The whole body markup of Default.aspx (including the user control with its button itself) resides in <form runat="server"> as required by ASP.NET. Everything works so far.
However, the problem is when I put some validation controls inside Default.aspx (meaning inside <form runat="server"> because otherwise the page will report server errors). When validation controls are added, the delete button in the user control stops working. Clicking on this button no longer triggers the event as before.
Now, I disabled event validation in Default.aspx using EnableEventValidation="false" directive. I am also including UnobtrusiveValidationMode = System.Web.UI.UnobtrusiveValidationMode.None; in the code behind file. However, none of this helps.
How do I fix this problem and make the button clickable?
Update:
I know for sure that the validation controls are causing the problem, because I only need to add EnableClientScript="False" to each of them, and the button becomes clickable. But I don't want to rewrite validation on the client side manually!
It turns out the PostBack cannot occur if the form is not IsValid regardless of what element causes it. As long as that element (button) is inside the form with runat="server"that is invalid, the posback will not happen.
A very simple workaround is to just make the Button in my user control bypass validation: CausesValidation="False" (thanks to this question).
Another solution and maybe a more efficient one, is to use ValidationGroup. This way, all TextBoxes together with the Submit Button will belong to one group, and those controls that do not belong to that group will NOT be validated. In fact, they might have their own ValidationGroup; this will avoid interference between different controls within one Web Form.

Validator behavior inside ASCX

I have some input fields, regular expression validators, and custom validators inside an ASP.NET ASCX control. The behavior is a bit odd in that it works the following way:
If a client side validator flags an error message and I tab away from the input field and click submit then the page posts as it should. However, if a client side validator has flagged an error and instead I correct the error and click submit button then the error is cleared but the page is not submitted until I click the submit button a second time.
My question is how do I change this behavior such that I only need to click the submit button once to both clear the error and postback the page? Also, is this "behavior" standard?
Update: This behavior occurs without using the user control. I believe it is specific behavior to the CompareValidator. Nope, same behavior occurs with custom validator. If I don't "tab away" and click the button then I must click it twice to get the postback to occur. The first click just clears the validators.
The issue is that the CustomValidator has display type as Dynamic and not Static. This post helped me to discover the answer
RequiredFieldValidator have to click twice
I will give credit for anyone who explains why it causes this behavior.

ASP.NET validation controls

I have a situation where I have a form that has some validation controls for required fields. They fire just fine if the user does not have the required fields.
The thing is I also have a menu above the form which allows the user to select another location which is then reflected on the form.
This is where I run into an issue...
If the user already selected a location and then wishes to change to a different location, the form does not allow for this as required fields have not been entered.
I was wondering if there is a way to tell the validation controls not to fire in these situation.
My other option would be to do a validation on click of the submit button in which case I would not be able to take advantage of the ASP.NET required validation control.
Basically I want the validation to occur for the required fields only if the submit button is clicked.
Look at CausesValidation and ValidationGroup properties. I think they will help you to solve your problem
On the menu item set CausesValidation to false.
You can also use validation groups and set the validationgroup property of the validator and the submit button to the same value.

ASP.NET - RequiredFieldValidator to validate only particular controls

I have a web form. There are many different sections. I can say that each section displays data of a datatable. At each section I have OK and Cancel buttons. When I press OK any changes to the table in the database takes place. I've also put some Requiredfieldvalidators. Let's say I'm inserting a new record in the section one and the fields are correctly typed. When I press OK I get error message raised by the rest of the validators that are on the other sections. Isn't there any way that when I press OK button of a particular section to get validation errors of that same area? So what I probably need is a button that will not serve as the hole page submitter but rather a submitter of a specific section.
Place a ValidationGroup on the RequiredFieldValidator's. Then place the same ValidationGroup on the correct submit button. When its clicked, only validation controls that are a part of the group are validated.
http://msdn.microsoft.com/en-us/library/ms227424.aspx
I think janhartmann is correct ValidationGroup can help you solve the issue.Have a look at this article

ASP.NET - Separate validation of two forms on one page?

I have what should be a fairly simple ASP.NET question, and one I thought I had found a workaround for in the past, but this time I'm having no end of bother trying to get a working solution for it.
I have an ASP.NET page with a number of input controls and a series of form validators for them. I wish the page to have separate forms where only some validators are fired by submit button A and others are fired by submit button B. An example would be a site that included a site search box with validation, and a comments section or form to fill in on the same page. When submitting comments you would not want the search validation to fire, and when running a search you would not want the comment form validators to fire.
What I need is a kind of 'validation panel', or separate form tags to enclose these sections in. Can anyone help?
You can use ValidationGroup property for this.
But don't forget, you can not have more then one form in your asp.net page.

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