Asp On Error Resume Next Scope
Contents |
Forums Links DISCUSSIONARCHIVES DISCUSSIONARCHIVES2 DISCUSSIONARCHIVES3 BLOG We didn't realize the site was so popular. Other Stuff How To Use On Error Resume Next Often when using ASP classic asp on error resume next or Active Server Pages with VBScript you will find it necessary to check for errors classic asp on error resume next example when you do certain things that may fail and then handle it accordingly. Things like opening a database connection or writing to a vbscript on error resume next scope text file come to mind. Generally if an error is encountered in your .asp file, the processing of your script stops and an error message is returned to the browser. If you want to continue processing your
Asp On Error Goto
page even if an error is encountered, include the following line at the beginning of your .asp file: <% On Error Resume Next %> That being said just ignoring errors in your code is not a very good idea. What you really want to do is handle the error in some way. The example below opens a database connection and shows you how to trap a potential error and do whatever you want because on error resume next vbscript example of it. In this case we are simply displaying the error. <% ConnectionString = "DBQ=c:\inetpub\wwwroot\mysite\data\mydatabase.mdb;Driver={Microsoft Access Driver (*.mdb)};" '*** This code checks the ConnectionString info you entered and reports back the error code if it is not ok Err.Clear On Error Resume Next Set ConnPasswords = Server.CreateObject("ADODB.Connection") ConnPasswords.Open ConnectionString If Err.Number <> 0 Then Response.Write (Err.Description& "
") Response.Write("This means there is most likely a problem with the" & vbCrLf) Response.Write("""ConnectionString"" info that you specified.
" & vbCrLf) Response.End End If On Error GoTo 0 %> We put the "On Error GoTo 0 at the end because that will essentially end the "on error resume next" That is something you want to do so any later errors in your application do not get ignored without you knowing about it. Below is another example. In this example our application logs user info in a text file when they sign in to a site. We add "On Error Resume Next" here simply so no nasty error message come up if by chance write permissions to the text file do not exist. <% Set ObjMyFile = CreateObject("Scripting.FileSystemObject") Err.Clear On Error Resume Next LogFileName = "aspprotect.log" LogFileDirectory = "c:\somedirectory" 'Open Text File.. If doesn't exist create it and append to it .. If exists just append to it
'On Error Resume Next' scope rules The SitePoint Forums have moved. You can now find them here. This forum is now closed to new posts, but you can browse existing content. You can find out more vbscript error handling best practices information about the move and how to open a new account (if necessary) here. If
Error Handling In Vbscript Tutorial
you get stuck you can get support by emailing forums@sitepoint.com If this is your first visit, be sure to check out the
On Error Resume Next Vbscript W3schools
FAQ by clicking the link above. You may have to register before you can post: click the register link above to proceed. To start viewing messages, select the forum that you want to visit from the selection http://www.powerasp.net/content/new/on-error-resume-next.asp below. SitePoint Sponsor User Tag List Results 1 to 2 of 2 Thread: QUERY: 'On Error Resume Next' scope rules Thread Tools Show Printable Version Subscribe to this Thread… Display Linear Mode Switch to Hybrid Mode Switch to Threaded Mode Jun 9, 2006,04:25 #1 dhruba.bandopadh View Profile View Forum Posts SitePoint Enthusiast Join Date Mar 2006 Posts 28 Mentioned 0 Post(s) Tagged 0 Thread(s) QUERY: 'On Error Resume Next' scope rules This has been puzzling http://www.sitepoint.com/forums/showthread.php?390744-QUERY-On-Error-Resume-Next-scope-rules me for very long time and no where has talked about the scope of a 'On Error Resume Next' statement. When we program ASP(.NET) pages then we usually like to let ASP(.NET) stop at errors and report back to us. However there are parts of our scripts that we know an error will be thrown and we encapsulate that area inbetween: On Error Resume Next Err.Clear 'Try block If Err.Number Then 'Catch block End If On Error GoTo 0 This is similar to the infamous try {} catch(e) {} blocks in Java/C++, etc. If we forget the last line 'On Error GoTo 0' then our ASP(.NET) scripts runs over all errors thrown and we find it hard to find bugs. So the big question is, does 'On Error Resume Next' go out of scope when it's written inside a block (eg. Function)? Function Function1() On Error Resume Next 'Our code End Function When the Function1 call returns, does the outside calling scope automatically stays as it was (On Error GoTo 0)? Jun 9, 2006,12:26 #2 bbolte View Profile View Forum Posts SitePoint Wizard Join Date Nov 2001 Location The Central Plains Posts 3,304 Mentioned 0 Post(s) Tagged 0 Thread(s) Originally Posted by dhruba.bandopadh When the Function1 call returns, does the outside calling scope automatically stays as it was (On Error
LippertAugust 19, 200419 0 0 0 OK, enough about the Peloponnesian war -- a number of readers have asked me questions about error handling in VBScript recently, so I think I'll talk about it a bit for the next few days. Today, I want to very https://blogs.msdn.microsoft.com/ericlippert/2004/08/19/error-handling-in-vbscript-part-one/ carefully describe what the error handling semantics are in the language, because there is some http://stackoverflow.com/questions/4999364/try-catch-end-try-in-vbscript confusion over how exactly it works. There are two statements that affect error handling in VBScript: On Error Resume NextOn Error Goto 0 The meaning of the first seems clear -- if you get an error, ignore it and resume execution on the next statement. But as we'll see, there are some subtleties. But before that, what the heck is up on error with the second statement? The second statement turns off ‘resume next' mode if it is on. Yes, the syntax is ridiculous -- something like On Error Raise would be a whole lot more clear. But for historical purposes, this is what we're stuck with. Visual Basic has an error handling mode which VBScript does not -- VB can branch to a labeled or numbered statement. (Remember line numbers? Those were the days!) To tell VB that on error resume you no longer wish to branch to that statement, you give zero, an invalid line number. C'est super-beaucoup-de-fromage, n'est-ce pas? But we're stuck with it now. The subtlety in the "resume next" mode is best illustrated with an example. Const InvalidCall = 5Print "Global code start"Blah1Print "Global code end"Sub Blah1() On Error Resume Next Print "Blah1 Start" Blah2 Print "Blah1 End"End SubSub Blah2() Print "Blah2 Start" Err.Raise InvalidCall Print "Blah2 End"End Sub This prints out Global code startBlah1 StartBlah2 StartBlah1 EndGlobal code end Hold on a minute -- when the error happened, Blah1 had already turned ‘resume next' mode on. The next statement after the error raise is Print "Blah2 End" but that statement never got executed. What's going on? What's going on is that the error mode is on a per-procedure basis, not a global basis. (If it were on a global basis, all kinds of bad things could happen -- think about how you'd have to design a program to have consistent error handling in a world where that setting is global, and you'll see why it's per-procedure.) In this case, Blah2 gets an error. Blah2 is not in ‘resume next' mode, so it aborts itself, records that there was an error situation, and returns to its caller. The caller sees the error, but the caller is in ‘resume next' mode, so it
here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about Stack Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up Try-Catch-End Try in VBScript up vote 22 down vote favorite 6 I'm trying the following code: Try Throw 2 'How do I throw an exception? Catch ex 'What do I do here? End Try but I'm getting the error Statement expected in the catch clause. Does anyone know how I can catch/throw exceptions in VBScript using try/catch? (I am not looking for solutions with On Error Do X.) vbscript try-catch share|improve this question asked Feb 15 '11 at 2:25 Mehrdad 103k64310611 3 Then you're going to be very disappointed. There's no Try-Catch support in pre-.NET versions of VB, including VB 6, VBA, and VBScript. On Error Resume Next isn't so bad if you know how to use it correctly. –Cody Gray Feb 15 '11 at 8:35 Yeah, I am disappointed. :( On Error Resume Next used to be my favorite command back in middle school, when I learned VB 6... it quickly became my most hated command after I learned C#. I guess I'll use it but I really don't want to. –Mehrdad Feb 15 '11 at 8:44 See below for some tips on using it correctly! :-) –Mark Ribau Sep 8 '11 at 5:30 add a comment| 4 Answers 4 active oldest votes up vote 16 down vote accepted VBScript doesn't have Try/Catch. (VBScript language reference. If it had Try, it would be listed in the Statements section.) On Error Resume Next is the only error handling in VBScript. Sorry. If you want try/catch, JScript is an option. It's supported everywhere that VBScript is and has the same capabilities. share|improve this answer answered Feb 15 '11 at 3:30 Tmdean 6,4482644 If it doesn't have Try/Catch, then how come it doesn't error