Handling Exceptions That Happen In A MVC Controller Constructor?
Apr 22, 2010
What's the best way to handle exceptions that happen from within a controller's constructor?
All I can think of to do is use Application_OnError() or put a try/catch in my ControllerFactory.
Neither of these solutions seem ideal. Application_OnError is to broad - I have some non-mvc content in the site that has its own error handling. Using a try/catch block seems kinda hacky.
If I'm serving different content type -html/text/json/rss.... I would like to be able to handle the exception from within the action method instead of having to write all kinds of conditions to determine what kind of error message to serve.
I have a datasource that uses a business logic object for the select event. How can I catch an exception that occurs in the business logic layer and pass it to my presentation layer to display to the user in a label?
The default behavior of a [WebMethod] attributed static method on an aspx page is to return the error to the caller. We are accessing these methods using json, and the only way we have found of capturing exceptions is either a try/catch in every webmethod on the site or using a javascript callback with the error (which has the unacceptable downside of exposing the error to the client).
Is there any way to globally handle these exceptions using the HealthMonitoring setup in ASP.NET?
I have what is probably a basic question, but I am rather new to writing exception handling code. I thought I understood the concept, but apparently I don't, heres the code:
[Code]....
If I enter in any non-integer values, the textbox is set to nothing and the label displays the error message. However, now that I have verified the textbox contains an integer, I want to continue on and use that value. The remaining code works fine unless there was an exception, in which case the conversion to an int value for x throws an error.
All the examples I have looked at demos the structure of try-catch-finally, but in this instance I am not performing any clean up, I want to execute code when a valid value is entered into the textbox.
I have error handling in Application_Error event of globals.asax file. Inside this event, I'm using Response.Redirect(~errorview.aspx) method, for redirection to site which is able to handle errors in user friendly way.
Everything works fine, unless exception is rising in Application_Start event. When error occurs there, my application gets trapped in infinite loop with the Application_Error method hit repeatedly. What is more, the page I'm redirecting to never gets hit. Changing Response.Redirect(~errorview.aspx) method to Response.Redirect(~errorview.aspx, false) changes nothing.
The good news is, when Response.Redirect(~errorview.aspx) has been replaced with Server.Transfer(~errorview.aspx), errorview.aspx page succesfully gets hit.
The side effect now is not loading CSS, and errorview.aspx page looks ugly. What is more, the CSS is not loaded only when exception occurs in Application_Start event. Exceptions thrown from any other place don't make the CSS mess.
How I can handle this problem in correct way, and why the CSS is missing in the one particular situation ? What is the appropriate way of handling errors in my case ?
I have been tasked with implementing a strategy to catch all errors in an ASP.net application which cause a user request or interaction to crash and then e-mailk this exception to a support team in advance of a user calling about the error.Some errors however are not causing the page to crash or be redirected to the custom error page but these are being emailed to the support team instead of simply being loggedMy requirement is to seperate what exception types will cause a page fail and which will not.Example I am currently receiving a System.Web.HttpUnHandledException which is not causing any page to fall over and therefore is not of relevance to the support team. this can be logged but does not require emailing.
Fine and dandy... I like that mode="RemoteOnly" facilitates development...
For unhandled exceptions, I have in global.asax:
Sub Application_Error(ByVal sender As Object, ByVal e As EventArgs) Response.Redirect("GenericError.aspx") End Sub
However, unhandled exceptions are going to the generic error page instead of the informative yellow screen of death preferred by developers. I can comment out the redirect in global.asax, but then I need to remember to change it for the production environment. Is there a way I can check in Application_Error whether I am remote or not to determine whether to redirect?
I have basic client-side validation working in my MVC3 RC2 application, but I'm now interested in recommended practices for conveying server side validation errors, as well as server side exceptions, to the client. I know I can add properties to my view model and display these if populated, but I don't want to reinvent the wheel, and I would like to tie in with MVC's way of doing things. So, how should I, a) notify the user of server side validation errors, and, b) notify the user of server side exceptions, e.g.
It would seem so to me, because nearly all exceptions thrown downstream of whatever routes requests to controllers, will be thrown in a controller or something downstream from a controller. There is nothing upstream from a controller except a view, which is simply a presentation of what happened in the controller.
I'm building the standard 3-tier ASP.NET web application but I'm struggling as to where to do certain things - specifically handling exceptions.
I've tried to have a look around on the web for some examples but can't find any which go as far as a whole project showing how everything links together.
In my data-tier I'm connecting to SQL Server and doing some stuff. I know I need to catch exceptions that could be raised as a result but I'm not sure where to do it.
From what I've read I should be doing it in the UI tier but in that case I'm not sure how to ensure that the connection to the database is closed. Is anyone able to clarify how to do this? Also if anyone knows as to where I could find an example 3-tier web application that follows best practices that would be great too.
We have a asp.net application and want to implement logging. The first idea was to use the Application_Error method in the global.asax file.
The problem is that ASP.NET very often seem to throw exceptions internally that are not caused by the application and which seem not to interfer with the users normal workflow. For example we often get HTTPExceptions, UnauthorizedAccessExceptions and others caught in this method, although there is no real error in the application.
UML and Patterns: An Introduction to Object-Oriented Analysis and Design and Iterative Development, that follows the UP(Unified Process). It uses a Grasp Controller pattern to interact with domain classes by some methods like NewSale(), AddNewItemToSale() and CloseSale. In windows form, I can instantiate a object of this class in the UI and then use its methods to perform the actions. This works well in Client apps, but when I use asp.net mvc, I cannot find a way to instantiate an object (one for each user) that was always visible for a Controller (MVC). I cannot insert as an attribute inside Controller because it always create a new one.
My code below has a drawback. The scenario is this, i have two user roles - Approvers and Encoders. The encoders are not allowed to view the price only the approvers. Using the code below, i can now hide the Price column. but the problem is, when the encoder modified the quantity column, the Total Amount (Quantity * Price ) is zero. Giving zero value for price. When the approvers view the transaction,the Total Amount is zero. Is that really the possible thing to happen when hiding a datafield?
HTML Code:
For Each colField As DataControlField In colFields If TypeOf colField Is BoundField Then Dim bField As BoundField bField = CType(colField, BoundField) If bField.DataField = "ReceivPrice" Then bField.Visible = False ' Hide Price Column End If End If Next
Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
If Request.ServerVariables("SERVER_PORT") = 80 Then Dim strSecureURL As String [code]....
The validation load in this page worked on the first click of btnDonation, if I don't change anything and click the btnDonation again, it automatically go to my confirm page. Instead, I want it to continue to check for requiredFieldsOK(). Note that if I fill in one of the missing required fields, the validation will work.
My question is: How can I continue to check for requiredFieldsOK() even if user didn't fill out any additional information?
Projectless development simplifies debugging: When creating a web project, you must recompile the entire application when you change a single page. With projectless development, each page is compiled separately, and the page is only compiled when you request it for the first time.
How does compiling happen only for the first time in projectless development?
Should it recompile every time I run the page to reflect the new code I wrote it?
I have view.aspx page that when I open page and don't do any thing in this page i.e for 10 minutes when I come back to this page after 10 minutes and click on hyperlink or button below error happen. Why this error happen?
This thing has just came to my head and I wanna share it.Note : I could easily test it but I am being lazy here to see if anybody has ever experienced something like that before.Let's assume that I have a web site which built-in membership structure of asp.net has been implemented on. What will happen to asp.net membership if the client browser blocks cookies? Does framework throw an exception when a user tries to log in or do something else?
I have a Wizard which has a FileUpload in one of the steps. It also has an "Upload" button. When the user browses to a file, and clicks Upload, I upload the file into SQL.
There seems to be some synchronization problem for very large files, and I would like to disable the Wizard's Next button until the Upload of the file to SQL completes. It can take a while, especially on a wireless PC.
In my OnClick event for the Upload button, I am trying to disable the Next button. The code, which is below, appears to be correct, but the Next button doesn't actually disable until the Query completes. Can I get the Next button to disable immediately instead of after the SQL Update completes?
Here is my code:
Protected Sub JustificationDocUploadButton_Click(ByVal sender As Object, ByVal e As EventArgs) Handles JustificationDocUploadButton.Click If RequestJustificationAttachment_FileUpload.HasFile Then Dim obj As Object = Wizard1.FindControl("StepNavigationTemplateContainerID") Dim startButton As Button = obj.FindControl("StepNextButton") startButton.Enabled = False SqlDataSourceJustificationAttachment.Update() End If End Sub
i have used template of datagrid that show product item.i want when buyer choose a product in datagrid the picture of the button in that cell change and next time click event or page load not happen for that specific button in datagrid.I SOLVE THAT PROBLEM BUT PAGE LOAD AND CLICK EVENT HAPPEN. what can i do?
I have a Custom Repeater control that inherits from Repeater and has paging functionality, however when I click the next page button the first time it refreshes the control but does not change the page, if I click it again after that it changes page perfectly. I know what the issue is, when I click the next button it does a postback, then the data is bound to the repeater, and then after that the NextButton Event is handled.
Is there any way I can change the order of the page load events?? Or force the repeater to reload again after the event is handled?? I've included my Custom Repeater class bellow:
using System.Web.UI.WebControls; using System.Web.UI; using System.Data; using System.Collections; using System; namespace ASPresentation.Controls { [ToolboxData("<cc:PagedRepeater runat=server></cc:PagedRepeater>")] public class PagedRepeater : Repeater { public int PageSize { get; set; } public int CurrentPageIndex { get { return Convert.ToInt16(Page.Session["ProjectIndex"]); } set { Page.Session.Add("ProjectIndex", value); } } public PagedDataSource pagedData = new PagedDataSource(); LinkButton NextBtn = new LinkButton(); LinkButton PrevBtn = new LinkButton(); public bool IsLastPage { get { return pagedData.IsLastPage; } } public bool IsFirstPage { get { return pagedData.IsFirstPage; } } public override object DataSource { get { return base.DataSource; } set { pagedData.DataSource = (IEnumerable)value; } } protected void NextButtonClick(object sender, EventArgs e) { if (!IsLastPage) { CurrentPageIndex++; } } protected void PrevButtonClick(object sender, EventArgs e) { if (!IsFirstPage) { CurrentPageIndex--; } } protected override void OnInit(EventArgs e) { base.OnInit(e); NextBtn.Text = "Next"; PrevBtn.Text = "Prev"; NextBtn.Click += new EventHandler(NextButtonClick); PrevBtn.Click += new EventHandler(PrevButtonClick); } protected override void OnLoad(EventArgs e) { base.OnLoad(e); base.Controls.Add(PrevBtn); base.Controls.Add(NextBtn); } protected override void Render(HtmlTextWriter writer) { base.Render(writer); } public override void DataBind() { pagedData.AllowPaging = true; pagedData.PageSize = PageSize; pagedData.CurrentPageIndex = CurrentPageIndex; base.DataSource = pagedData; base.DataBind(); } } }
my MVC2 delete and only my delete controller is refusing to return any class information. Its really similar to my edit function and the views are all auto-generated so I don't see the problem.
Function Delete(ByVal id As Integer) As ActionResult
I have a simple model where a Person has Gifts. I have a view which is a list of Gifts belonging to one Person.
My problem is with the Create action for a new Gift. I want it to default to the PersonID that we are already viewing the list of Gifts for. I tried simply passing the last PersonID (they are all the same)
Html.ActionLink("Create New", "Create", new { id = Model.Last().PersonID }) which works fine if there is already at least one Gift for that person but if this is the first Gift I don't have a value.
My Gift List controller knows the PersonID I want to pass but the view doesn't.
How do I pass this PersonID from my Gift List controller to my Gift Create controller via the Gift List view? Or is there a better way to do this?
