URL rewriting for static resources

Question

I know you can serve static HTML by uploading it as a static resource, but is it possible to create a URL rewrite rule for a static resource?

Something like this

if (url.startsWith('/coach')){    
    return new PageReference('/resources/coach/index.html');
}

Navigating directly to /resources/coach/index.html works, but the rewrite rule doesn't?

Ideally I'd love to do something even more advanced like this, to be able to access any file in a zip'd static resource.

List<String> segments = url.split('/');

if (url.startsWith('/coach')){    
    return new PageReference('/resources/coach/'+ segments[1]);
}

Any ideas?

Answer 1

Disclaimer: a 'tricky' attack surface indicates this may not be the best kind of problem to solve with Salesforce ;) so double check your real business requirements and push back on those if necessary!

First idea:

You might use the Site.UrlRewriter interface to do this on a Force.com Site, for eg:

public class UrlRewriter implements Site.UrlRewriter {

    public PageReference mapRequestUrl(PageReference incoming) {
        return new PageReference('/resource/1394899484000/SiteSamples/SiteStyles.css');
    }

    public PageReference[] generateUrlFor(PageReference[] yourSalesforceUrls) {
        return null;
    }
}

However the return signature of the implementor must be a PageReference resolving to a real page! I tried this for real and Salesforce serves a 404, not the file inside a zipped static resource!

Second idea:

You could create a real Visualforce Page as a kind of proxy that serves up the contents of the zip file using Apex, and point your URL Rewriter at that page:

Example: https://stackexchange-developer-edition.na14.force.com/coach/foo/bar

UrlRewriter.cls

public class UrlRewriter implements Site.UrlRewriter {

    public PageReference mapRequestUrl(PageReference incoming) {
        return new PageReference('/apex/ResourceReader');
    }

    public PageReference[] generateUrlFor(PageReference[] yourSalesforceUrls) {
        return null;
    }
}

ResourceReader.page

<apex:page controller="ResourceReaderController" contentType="text/plain">
    <apex:outputText value="{!Content}" escape="false" />
</apex:page>

ResourceReaderController.cls

public class ResourceReaderController {

    public String getContent() {
        return new PageReference('/resource/1394899484000/SiteSamples/SiteStyles.css').getContent().toString();
    }

}

Third idea:

Maybe try using Site URL Redirects which can do a 301 or 302 redirect you. It won't be transparent to the visitors, but you can see an example of that here:

Example: https://stackexchange-developer-edition.na14.force.com/coach/herp/derp

However these guys exist as 0H0 prefix objects and must be administered through the user interface. I'm not sure you will ever be able to upload a zip file and automatically drill into it.