Solved

User entered URL validation

Posted on 2003-12-11
13
437 Views
Last Modified: 2013-11-20
Could anyone help me out with some validation code to remove all invalid characters from a string? I was hoping to find a way of using CString.Remove by specifying a range of ASCII numbers to remove. For instance, remove all ASCII chars with code less than 48. Obviously I could go through and say

strURL.Remove(‘ ‘);
strURL.Remove(‘£‘);
strURL.Remove(‘$‘);

and so on but that’s not very efficient and a lot more work! Any help much appreciated!

Cheers,
Will
0
Comment
Question by:wjdashwood
[X]
Welcome to Experts Exchange

Add your voice to the tech community where 5M+ people just like you are talking about what matters.

  • Help others & share knowledge
  • Earn cash & points
  • Learn & ask questions
  • 6
  • 5
  • 2
13 Comments
 
LVL 86

Accepted Solution

by:
jkr earned 500 total points
ID: 9921960
Why don't you use 'InternetCanonicalizeUrl()' and check the result for 'ERROR_INTERNET_INVALID_URL'?
0
 

Author Comment

by:wjdashwood
ID: 9922280
Never even heard of that before. Excellent! I'll investigate further.

Cheers,
Will
0
 
LVL 23

Expert Comment

by:Roshan Davis
ID: 9925737
Thatz a nice one!

You can try this also..

IsValidURL()


Syntax
=====

HRESULT IsValidURL(
    LPBC pBC,
    LPCWSTR szURL,
    DWORD dwReserved
);


Parameters
========

pBC
        It should be set to NULL.
szURL
        Address of a string value that contains the full URL to be checked.

dwReserved
        Reserved. Must be set to zero.


Return Value
=========

Returns one of the following values:

S_OK The szURL parameter contains a valid URL.
S_FALSE The szURL parameter does not contain a valid URL.
E_INVALIDARG One of the parameters is invalid.

Function Information
===============

Header Urlmon.h
Import library Urlmon.lib
Minimum availability Internet Explorer 3.0
Minimum operating systems Windows NT 4.0, Windows 95


Rosh :)
0
Independent Software Vendors: We Want Your Opinion

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

 
LVL 23

Expert Comment

by:Roshan Davis
ID: 9925746
Ooops, the above function is only for validating the URL
0
 

Author Comment

by:wjdashwood
ID: 9949979
I'm trying to get InternetCanonicalizeUrl() to work but GetLastError simply returns ERROR_INVALID_PARAMETER. Can someone help me with the useage?

Thanks,
Will
0
 
LVL 86

Expert Comment

by:jkr
ID: 9950017
>>ERROR_INVALID_PARAMETER. Can someone help me with the useage?

How *are* you using it?
0
 

Author Comment

by:wjdashwood
ID: 9950143
LPDWORD lpdwBufferLength = NULL;
LPTSTR lpszBuffer = NULL;
LPCTSTR lpszUrl = _T("http://www.experts-exchange.com/");

InternetCanonicalizeUrl(lpszUrl,lpszBuffer,lpdwBufferLength,NULL));

DWORD dwLastError = GetLastError();
if (dwLastError == ERROR_INVALID_PARAMETER)
      AfxMessageBox("ERROR_INVALID_PARAMETER");
if (dwLastError == ERROR_INTERNET_INVALID_URL)
      AfxMessageBox("ERROR_INTERNET_INVALID_URL");


I guess I'm not delcaring or passing lpszBuffer and lpdwBufferLength correctly.
0
 
LVL 86

Expert Comment

by:jkr
ID: 9950311
>>LPDWORD lpdwBufferLength = NULL;
>>LPTSTR lpszBuffer = NULL;

That actually is the problem - the API expects a buffer to receive the output, not a NULL pointer. And, what's worese, the buffer size parameter is a null pointer also.

Make it read

LPCTSTR lpszUrl = _T("http://www.experts-exchange.com/");
DWORD dwBufferLength = 2 * _tcslen ( lpszUrl); // worst case
TCHAR szBuffer [ dwBufferLength];

InternetCanonicalizeUrl(lpszUrl,szBuffer,&dwBufferLength,NULL));


0
 

Author Comment

by:wjdashwood
ID: 9950923
Many thanks. I'll give that a try.
0
 

Author Comment

by:wjdashwood
ID: 9964829
I've got it working (I had to declare a size of the szBuffer) but the function doesn't seem to remove invalid characters. Is there a flag I need to set or something?
0
 
LVL 86

Expert Comment

by:jkr
ID: 9966141
>>but the function doesn't seem to remove invalid characters

Hm, it should *test* for them (at least this was my intention) - removing chars is a bit dangerous, as in approx. 90% of all cases you won't end up with an existing URL
0
 

Author Comment

by:wjdashwood
ID: 9966188
Well your algorithm in the other question does exactly what I want and probably much faster :)
0
 
LVL 86

Expert Comment

by:jkr
ID: 9966244
Well, we have a proverb here about 'catching two flies with a single slap' :o)
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Suggested Solutions

Title # Comments Views Activity
sameEnds challenge 3 194
Hibernate methods 2 87
ShiftLeft challenge 21 95
mapBully challenge 6 196
Here is how to use MFC's automatic Radio Button handling in your dialog boxes and forms.  Beginner programmers usually start with a OnClick handler for each radio button and that's just not the right way to go.  MFC has a very cool system for handli…
Have you tried to learn about Unicode, UTF-8, and multibyte text encoding and all the articles are just too "academic" or too technical? This article aims to make the whole topic easy for just about anyone to understand.
This video will show you how to get GIT to work in Eclipse.   It will walk you through how to install the EGit plugin in eclipse and how to checkout an existing repository.

739 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question