Always Include Server Url without a HttpContext

Recently we had a requirement to update an external API with content information when new items were published. The external source needed general content like titles, images etc… But also needed a full link to the page. The implementation is a multi-site install and any of the sites could send data to the external API.

The plan was to use the item:saved event and if the database was the delivery database, add the item to a queue. Then on publish:end we can process the queue and send the data.

###AlwaysIncludeServerUrl
Getting the full url to a page is nice and simple in Sitecore, we can just set the LinkOptions.AlwaysIncludeServerUrl = true;.

var options = LinkManager.GetDefaultUrlOptions();
options.AlwaysIncludeServerUrl = true;
var url = LinkManager.GetItemUrl(item, options):

But by default that uses the current SiteContext to get the host name. Because we are running this in an event, the SiteContext wouldn’t be our delivery site, it would be the Shell site. So we need to run the link manager in a different SiteContext. We can do this with a SiteContextSwitcher. So we created a method to work out the site based on the location of the item and then ran the link manager in that sites context:

var site = this.ContentManager.GetSiteFromItem(item);
using (new SiteContextSwitcher(site))
{
    var options = LinkManager.GetDefaultUrlOptions();
    options.AlwaysIncludeServerUrl = true;
    var url = LinkManager.GetItemUrl(item, options):
}

To make this work properly, we also need to set the targetHostName in our site definitions config:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
      <sites>
          <site name="Site1" patch:before="site[@name='website']"
			  hostName="site1.local|www.site1.com"
			  rootPath="/sitecore/content/sites/site1/"
			  startItem="/home"
			  database="web"
			  language="en"
			  allowDebug="true"
			  cacheHtml="true"
			  htmlCacheSize="10MB"
			  enablePreview="true"
			  enableWebEdit="true"
			  enableDebugger="true"
			  disableClientData="false"
			  enableCustomErrors="true"
			  targetHostName="www.site1.com"
			/>
          <site name="Site2" patch:before="site[@name='website']"
			  hostName="site2.local|www.site2.com"
			  rootPath="/sitecore/content/sites/site2/"
			  startItem="/home"
			  database="web"
			  language="en"
			  allowDebug="true"
			  cacheHtml="true"
			  htmlCacheSize="10MB"
			  enablePreview="true"
			  enableWebEdit="true"
			  enableDebugger="true"
			  disableClientData="false"
			  enableCustomErrors="true"
			  targetHostName="www.site2.com"
			/>
            <!-- etc... -->
        </sites>
  </sitecore>
</configuration>

And now everything works nicely - we can generate the correct Urls for our content and pass it over to our 3rd party… Or so I thought. Actually what happened was that the urls being generated did not include the scheme for the site. So instead of getting this:

http://www.site1.com/page1/ we got ://www.site1.com/page1/

My first thought was to include the scheme in the targetHostName. But that returned ://http://www.site1.com/page1/ - so somewhere in the Sitecore LinkProvider that :// was being added and Sitecore could not work out the scheme.

###WebUtil.GetScheme - HttpContext tightly coupled again…
So into dotPeek we go, lets have a look at what Sitecore is doing. The GetItemUrl method calls LinkProvider.GetServerUrlElement to build that server part. This is the code in question:

string @string = StringUtil.GetString(new string[2]
{
    siteInfo.Scheme,
    this.GetScheme()
});
string str5 = @string + "://" + str4;
return str5;

And GetScheme calls WebUtil.GetScheme()

public static string GetScheme()
{
    HttpContext current = HttpContext.Current;
    if (current != null)
        return current.Request.Url.Scheme;
    return string.Empty;
}

Ah - now we see the problem, in the publish:end event HttpContext.Current == null. So the scheme is always going to be empty! Fortunately, it looks like we can set the scheme using the site definition, this line siteInfo.Scheme looks like it should help here. This is in the constructor on the SiteInfo class:

this.scheme = StringUtil.GetString(new string[1]
{
    properties["scheme"]
});

So now the site definition looks like this:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/">
  <sitecore>
      <sites>
          <site name="Site1" patch:before="site[@name='website']"
			  hostName="site1.local|www.site1.com"
			  rootPath="/sitecore/content/sites/site1/"
			  startItem="/home"
			  database="web"
			  language="en"
			  allowDebug="true"
			  cacheHtml="true"
			  htmlCacheSize="10MB"
			  enablePreview="true"
			  enableWebEdit="true"
			  enableDebugger="true"
			  disableClientData="false"
			  enableCustomErrors="true"
			  targetHostName="www.site1.com"
              scheme="http" <!-- Scheme added for http -->
            />
            <!-- etc... -->
        </sites>
  </sitecore>
</configuration>

Now the url is created correctly: http://www.site1.com/page1/. Yay!

Its not the perfect solution, setting the scheme in the config will override the HttpContext.Current.Request.Url.Scheme value, so if you are on https and the site is set to http the links will not be generated correctly. Because our requirement will only ever run on the authoring server, we have a transform for the delivery servers that removes the scheme from the site definition for the delivery servers.

###tl;dr

• Wrap the LinkManager.GetItemUrl in a SiteContextSwitcher
• In the SiteDefinition, Make sure the targetHostName and the scheme proeprties are set
• Enjoy urls with the host name when there is no HttpContext

– Richard.