IIS URL Rewriting with Routing for Subdomains and Optional Parameters in ASP.Net 4.5 Webforms

Question

I am trying to combine IIS URL Rewriting with routing in an ASP.Net 4.5 webforms site for subdomains and sub-directories.

I am trying to combine URL Rewriting in IIS with Routing in ASP.Net 4.5 for a webforms site. The solution I have right now works great for rewriting a subdomain with optional parameters to routing values, but I am struggling to pass sub-directory URLs to routes or querystrings. Most of the parameters I am working with are also optional so the rules have to consider any combination of those parameters or nothing.

The end goal is a feathering effect with hyphen separated locations on the subdomain side and categories on the sub-directory side. For instance a URL containing all parameters would be something like http://city-state.example.com/categoryslug/subcategoryslug

The rule I have in place in my web.config for the subdomains and the routes I have in my RouteConfig.cs are as follows:

<rewrite>
      <rules>
      <rule name="Rewrite subdomains">
        <match url=".*" />
        <conditions>
          <add input="{HTTP_HOST}" pattern="^(^$|[^\-]*)(^$|[\-]?)([^\-]\w)\.example\.net$" />
          <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
        </conditions>
        <action type="Rewrite" url="{ToLower:/local/{C:3}/{C:1}}" />
    </rule>

      </rules>
      <outboundRules>
        <rule name="RewriteRelativePaths" preCondition="ResponseIsHtml1">
          <match filterByTags="A, Area, Base, Form, Frame, Head, IFrame, Img, Input, Link, Script" pattern="^/(.*)" negate="false" />
          <action type="Rewrite" value="http://example.net/{R:1}" />
        </rule>
        <preConditions>
          <preCondition name="ResponseIsHtml1">
            <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
          </preCondition>
        </preConditions>
      </outboundRules>
    </rewrite>


From RouteConfig.cs

// Geographic SubDomains
            routes.MapPageRoute("local/state", "local/{state}", "~/local/Default.aspx");
            routes.MapPageRoute("local/state/city", "local/{state}/{city}", "~/local/Default.aspx");


Potential Conflicting routes:

//Category
            routes.MapPageRoute("category", "{catslug}", "~/category/Default.aspx");
            //SubCategory
            routes.MapPageRoute("category/subcategory", "{catslug}/{scatslug}", "~/category/Default.aspx");

The expected result in the end should rewrite something like http://city-state.example.com/categoryslug/subcategoryslug to ~/local/{state}/{city}/{categoryslug}/{subcategoryslug} but I see a potential conflict between that route and something like ~/local/{state}/{categoryslug} in which I don't think the application will be able to distinguish between state/category and state/city.

I also have some potentially conflicting routes for category/subcategory where the root domain displays categories using slugs. My concern there is that a route containing the same pattern of category/subcategory might end up being sent to the root domain instead of the subdomain.

Due to the aforementioned concerns I think using querystrings for the categories would be better than using routes. right now I can load a page at http://city-state.example.com/?category=categoryslug&subcategory=subcategoryslug just fine. Next I would like to be able to change those querystrings to categoryslug/subcategoryslug and rewrite it to /local/{state}/{city}/?categoryslug=categoryslug&subcategoryslug=subcategoryslug. I DO NOT want the url rewritten to anything like?category=&subcategory= because that would not be compatible with how the pages select data based on querystrings.

Answer 1

  <rule name="Rewrite subdomains">
    <match url=".*" />
    <conditions>
      <add input="{HTTP_HOST}" pattern="^(^$|[^\-]*)(^$|[\-]?)([^\-]\w)\.example\.com$" />
      <add input="{REQUEST_FILENAME}" matchType="IsFile" negate="true" />
    </conditions>
    <action type="Rewrite" url="{ToLower:/local/{C:3}{C:2}{C:1}{PATH_INFO}}" appendQueryString="true" />
</rule>

  </rules>
  <outboundRules>
    <rule name="RewriteRelativePaths" preCondition="ResponseIsHtml1">
      <match filterByTags="A, Area, Base, Form, Frame, Head, IFrame, Img, Input, Link, Script" pattern="^/(.*)" negate="false" />
      <action type="Rewrite" value="http://example.com/{R:1}" />
    </rule>
    <preConditions>
      <preCondition name="ResponseIsHtml1">
        <add input="{RESPONSE_CONTENT_TYPE}" pattern="^text/html" />
      </preCondition>
    </preConditions>
  </outboundRules>
</rewrite>