URL Rewriting with RegExp 1

[bdichiara]

I have tried and tried to understand how this works, and I cannot figure out for the life me 1: Regular Expressions and 2:How to format them for URL-Rewriting.

I'm using some code I found online that does URL-rewriting but I don't know how to set up my rules. Here's an example:

<rule name="Search Page"><!--probably wrong...-->
	<url>/([a-zA-Z][\w-]{1,149})\/</url>
	<rewrite>/search.aspx?q=$1</rewrite>
</rule>
<rule name="Content Page">
	<url>/([a-zA-Z][\w-]{1,149})/([a-zA-Z][\w-]{1,149})\/</url>
	<rewrite>/content.aspx?Category=$1&amp;Item=$2</rewrite>
</rule>

Here are the rules I want.
1. I have a stylesheet and javascript files that I don't want to break when rewriting kicks in.
2.

http://www.domain.com/Default.aspx

shows up as

http://www.domain.com/(nothing)

3.

http://www.domain.com/search.aspx?q=search+text

converts to:

http://www.domain.com/s/search+text/

4.

http://www.domain.com/content.aspx?c=category&p=page

converts to:

http://www.domain.com/category/page/

Is this possible/difficult? Please help, I would greatly appreciate it.

_______________
_brian.

 

[earthandfire]

I know nothing at all about ASP.Net, but the following might point you in the right direction - I've tested it in WinForms and it seems to meet your requirements:

  Private Function MatchEval(ByVal m As Match) As String

    If m.ToString.StartsWith("Default") Then
      Return "(nothing)"
    Else
      If m.ToString.StartsWith("search") Then
        Return "s/"
      Else
        If m.ToString.StartsWith("content") Then
          Return "category/"
        Else
          Return m.ToString
        End If
      End If
    End If


  End Function

  Private Const dmn As String = "[URL unfurl="true"]http://www\.domain\.com/"[/URL]
  Private ptrn As String = _
   "(?<=" + dmn + ")" + "Default.aspx|search\.aspx\?q=|content\.aspx\?c=category&amp;p="

  Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click

    Dim rx As New Regex(ptrn)
    TextBox2.Text = rx.Replace(TextBox1.Text, AddressOf MatchEval)

  End Sub

with: [tt]Imports System.Text.RegularExpressions[/tt] at the top of the Form.


Hope this helps.

 

[Aptitude]

You can find details of the regular expression language here:

[URL unfurl="true"]http://msdn2.microsoft.com/en-us/library/az24scfc(VS.71).aspx[/url]

To achieve what you want you will need to set your config file up like this:

<rule name="Default Page">
    <url>(?i)/Default.aspx</url>
    <rewrite>/</rewrite>
</rule>
<rule name="Search Page">
    <url>(?i)/s/(?<SearchText>.*)/</url>
    <rewrite>/search.aspx?q=${SearchText}</rewrite>
</rule>
<rule name="Categories">
    <url>(?i)/s/(?<Category>.*?)/(?<Page>.*?)/</url>
    <rewrite>/content.aspx?c=${Category}&amp;p=${Page}</rewrite>
</rule>

I'll explain the last one in steps:

<url>

(?i) - sets the RegEx to not be case sensitive
/s/ - matches anything that starts '/s/'
(?<Category> - starts a group that has a name 'Category' that can be used in the replace string.
. - matches any character
* - tells the RegEx to match the '.' zero or more times
? - tells the '.*' combination to not be greedy. So with '/hello/friend/' it will match 'hello' and stop there and will not go onto match 'hello/friend' leaving 'friend' for the following Page Group.
) - Closes the group
/ - matches '/'
(?<Page>.*?)/ - as with the Category group, matches everything up to the next slash and places it into a group called Page.

<rewrite>
/content.aspx?c=${Category}&amp;p=${Page}

This makes the new URL look exactly as written with ${Category} and ${Page} replaced with the text matched by the groups with the same name in the <url> rule.

The code you are using is likely to only rewrite URLs on the way into your web site. When your site writes out URLs it will need to re-write them correctly using some code similar to earthandfire's above. Rewriting URLs will cause any relative paths in your site to be messed up if you are rewriting a page to a different level in the directory structure. To prevent this you may want to investigate placing a <base></base> tag in the header of each page.

There are lots of niggling issues with re-writing URLs in Asp.Net for example the framework automatically generates the path for the main <form action=""> attribute. So make sure you do plenty of testing and ensure you know why you are doing this so you can decide what is and isn't going to be an issue.

 

[bdichiara]

Hey Aptitude,

Thanks for helping me out. I tried to use that XML and the system didn't like it. I guess it thinks the <SearchText> is an XML tag. I get:

 Exception Details: System.Xml.XmlException: The 'SearchText' start tag on line 8 does not match the end tag of 'url'. Line 8, position 35.

Any ideas?

_______________
_brian.

 

[bdichiara]

Ok, maybe this will help. I think I found a better one that uses RegEx, and it's it uses the web.config file. The setup is like this:

<add url="~/(.*)default\.aspx" mappedUrl="~/$1default.aspx" />
<add url="~/search\.aspx?q=(.*)" mappedUrl="~/search.aspx?q=$1" />
<add url="~/(.*)/(.*)\.aspx" mappedUrl="~/content.aspx?c=$1&amp;p=$2"/>

I decided just to use the query string variable for my search page, since I can't change the URL that my search form submits to. So I would like my rules as follows:
1 & 2 Remain the same
3. ~/search.aspx?q=search+text needs to stay the same.
4. ~/content.aspx?c=category&amp;p=page converts to: ~/category/page/

Now, I feel like I've tried everything to get #4 to work, but it keeps acting like it can't find the file, so the best I could do was get to look like: ~/category/page.aspx, however I still would like for that to work, if possible.

_______________
_brian.

 

[Aptitude]

Thanks for helping me out. I tried to use that XML and the system didn't like it. I guess it thinks the <SearchText> is an XML tag. I get:

Oops I didn't spot that issue. You can either replace < and > with &lt; and &gt; or use a CDATA section like this:

<rule name="Default Page">
    <url>(?i)/Default.aspx</url>
    <rewrite>/</rewrite>
</rule>
<rule name="Search Page">
    <url>![CDATA[(?i)/s/(?<SearchText>.*)/]]</url>
    <rewrite>/search.aspx?q=${SearchText}</rewrite>
</rule>
<rule name="Categories">
    <url>![CDATA[(?i)/s/(?<Category>.*?)/(?<Page>.*?)/]]</url>
    <rewrite>/content.aspx?c=${Category}&amp;p=${Page}</rewrite>
</rule>

 

[bdichiara]

Ok, here are my 2 URL Rewrites:

<add url="~/(.*)default\.aspx" mappedUrl="~/$1default.aspx" />
<add url="~/(.*)/(.*)\.aspx" mappedUrl="~/content.aspx?c=$1&amp;p=$2"/>

but I just need 1 thing: I want the URL to rewrite like this:

mydomain.com/category/
to
mydomain.com/content.aspx?c=category&amp;p=default

For some reason, anytime I try to setup a URL rewrite to something that doesn't end in aspx, it just acts if it's looking for a folder. I really would like my URLs to end in '/' rather than .aspx.

_______________
_brian.

 

[mbiro]

http://www.tek-tips.com/viewthread.cfm?qid=1365884&page=1