Of Code and Me

Somewhere to write down all the stuff I'm going to forget and then need

Search Webservice for SharePoint / Search Server with configurable timeout December 10, 2009

Filed under: C#,Search Server — Rupert Bates @ 5:11 pm

Anyone who has used Microsoft Search Server or the search.asmx Query service in Sharepoint to search a site of any size has probably run into the System.ServiceProcess.TimeoutException error. This is caused by the search failing to complete within 10 seconds at which point sharepoint throws this exception.

Anyone who has then Googled this error will probably have found out that this 10 second limit is (amazingly) hard coded into the QueryService class and so cannot be extended. The only suggestion I have seen for getting round this is to write your own webservice which uses the same classes as QueryService to perform a search and so that is what I have done.

I should point out that this is not really my code, I used Reflector to decompile the QueryService class and then made some modifications to get it to compile (see notes), so this really is the same code that search.asmx uses.

To make use of this code:
1. Download and unzip the files

2. Copy:

SearchWithTimeout.asmx
SearchWithTimeoutWsdl.aspx
SearchWithTimeoutDisco.aspx

To: c:\Program Files\Common Files\Microsoft Shared\web server extensions\12\ISAPI

3. Install Guardian.SearchServer.dll into the GAC. The easiest way to do this is to copy the dll to C:\Windows\Assembly

That’s it, just use this searchWithTimeout.asmx in the same way you would have used search.asmx; add a service reference then call the QueryEx method passing in the same queryXml along with the timeout in milliseconds:

var searchServiceQuery = new SearchServer.SearchWithTimeoutSoapClient();
            
            searchServiceQuery.ClientCredentials.Windows.ClientCredential.Domain = ConfigurationManager.AppSettings["SearchServer.Domain"];
            searchServiceQuery.ClientCredentials.Windows.ClientCredential.UserName = ConfigurationManager.AppSettings["SearchServer.Username"];
            searchServiceQuery.ClientCredentials.Windows.ClientCredential.Password = ConfigurationManager.AppSettings["SearchServer.Password"];
            searchServiceQuery.ClientCredentials.Windows.AllowedImpersonationLevel = System.Security.Principal.TokenImpersonationLevel.Impersonation;
            searchServiceQuery.ClientCredentials.Windows.AllowNtlm = true;

            //Verify that the Search Server is up and running
            if (string.Compare(searchServiceQuery.Status(), "ONLINE", true) != 0)
                throw new Exception("The Search Server isn't online.");

            var timeout = int.Parse(ConfigurationManager.AppSettings["SearchServer.TimeoutInMilliseconds"]);
            var searchResults = searchServiceQuery.QueryEx(query, timeout);
            
            searchServiceQuery.Close();

Notes

In the assembly in which you reference the webservice you need to change the Config setting in System.ServiceModel\bindings\basicHttpBinding\binding
to set the mode to “TransportCredentialOnly” and the Transport clientCredentialType to “Windows” or “NTLM” (this is the same as with the original Search Server webservice, more info here). This should look as follows:

          <security mode="TransportCredentialOnly">
            <transport clientCredentialType="Windows" proxyCredentialType="None"
              realm="" />
            <message clientCredentialType="UserName" algorithmSuite="Default" />
          </security>

My webservice only has a subset of the methods that can be found on search.asmx/QueryService, this is because the missing methods used classes which were internal to Microsoft.Office.Server.Search.dll so I couldn’t reproduce their functionality. If you need the other methods then reference both webservices.
The methods I have reproduced are:

  • QueryEx
  • Query
  • Status
  • GetSearchMetadata

I have only tested Status and QueryEx, so I would be keen to hear from anyone on whether the other methods work as expected.
I have also had to make the following changes (all of them because the original code used internal classes):

  1. removed some logging code that was in the original webservice
  2. changed an exception type
  3. exceptions do not load messages from the resource file
 

Making IEnumerable Default Comparer work with your own types November 26, 2009

Filed under: C#,Linq — Rupert Bates @ 11:22 am

As part of the Open Platform client library I have created a type for the tags that are returned by the api:

	//Attributes omitted for brevity
	public class Tag
	{
		public string Name { get; set; }
		public string Type { get; set; }
		public string Filter { get; set; }
		public string ApiUrl { get; set; }
		public string WebUrl { get; set; }
	}

The Filter property acts like a primary key so if two Tag objects have the same Filter then they should be considered equal.
This test describes the behaviour I want:

		[Test]
		public void Test_tag_equality()
		{
			Tag t1 = new Tag { Filter = "/Rupert" };
			Tag t2 = new Tag { Filter = "/Rupert" };
			Tag t3 = new Tag { Filter = "/Harry" };
			Tag t4 = t3;
			Assert.AreEqual(t1, t2);
			Assert.AreNotEqual(t1, t3);
			Assert.AreNotSame(t1, t2);
			Assert.AreSame(t3, t4);
		}

So I overrode Equals

        public override bool Equals(object obj)
        {     
            return Filter == ((Tag) obj).Filter;
        }

and my test passed.
However later on I wanted to use IEnumerable.Intersection() to find all the elements from one list that were also in another list as follows:

//Get the tags which match with music types
            var musicTypes = new[]
			{
				new Tag{Filter="/music/popandrock"}, 
                new Tag{Filter="/music/classicalmusicandopera"}, 
                new Tag{Filter="/music/electronicmusic"}, 
                new Tag{Filter="/music/urban"},
                new Tag{Filter="/music/folk"},
                new Tag{Filter="/music/worldmusic"}
            };

            //filter the results to get the ones which are tagged with the musicType tags
            var filtered = results.Results.Where(c => c.TaggedWith.Intersect(musicTypes).Count() > 0);

but my intersection always returned 0 matches, in other words the way that Intersect() was comparing the equality of the elements of my IEnumerable was not using my Equals() override (or not exclusively anyway). There is an overload for this function that takes a custom EqualityComparer, but I didn’t want to use that.
I investigated a bit more and found that IEnumerable uses the IEquatable interface to determine whether elements are equal so I implemented this and thought that would be that:

	public class Tag : IEquatable<Tag>
	{
		...

		#region IEquatable<Tag> Members

		public bool Equals(Tag other)
		{
			return Filter == other.Filter;
		}

		#endregion
	}

but my intersection still failed to return any results.
After quite a bit of head scratching I tried implementing GetHashCode() as well and finally it worked

	//The final implementation
	public class Tag : IEquatable<Tag>
	{
		...

		public override bool Equals(object obj)
		{
			return Filter == ((Tag)obj).Filter;
		}
		public override int GetHashCode()
		{
			return Filter.GetHashCode();
		}
		#region IEquatable<Tag> Members

		public bool Equals(Tag other)
		{
			return Filter == other.Filter;
		}
		#endregion
	}

Stepping through the code with the debugger it seems that all of these methods are called. It actually works correctly without the IEquatable implementation, but I have left it in for completeness.

 

New .Net Client Library for Guardian Open Platform

Filed under: Asp.Net,C#,guardian.co.uk,Web — Rupert Bates @ 10:30 am

I’ve recently created a .Net client library for the Guardian’s Open Platform API which allows you to query guardian.co.uk, pull back content and ‘Build applications with the Guardian’.

The project is open source and hosted on codeplex.

You can find out more about the Open Platform API here:

http://www.guardian.co.uk/open-platform

 

Use CacheProfile attribute with output caching in asp.net mvc November 22, 2009

Filed under: Asp.Net,C#,MVC,Web — Rupert Bates @ 9:21 pm

I’ve recently been setting up some caching on a new Asp.Net MVC site by using the OutputCache attribute on my controllers:


//cache this for an hour
 [OutputCache(Duration=60 * 60, VaryByParam="")]

This works really well except that it means hard codeding the cache time into my app so if I want to change it I need to recompile and deploy my code which is obviously far from ideal. So I changed my code to load the value from the web.config and ran into this error:

‘An attribute argument must be a constant expression, typeof expression or array creation expression of an attribute parameter type’

Not very helpful.

But fortunately there is a better way of doing all this using cache profiles, I just set up a cache profile in my web.config:


<system.web>
<caching>
<outputCacheSettings>
<outputCacheProfiles>
<add name="HomePage" duration="3600" varyByParam="None" location="ServerAndClient"/>
</outputCacheProfiles>
</outputCacheSettings>

</caching>

</system.web>

And then reference this in my attribute:

 [OutputCache( CacheProfile="HomePage")]

And bingo, we’re sucking diesel as a friend of mine says!

 

Create an Asp.Net MVC HtmlHelper for use in unit tests November 17, 2009

Filed under: Asp.Net,C#,Coding,MVC,Web — Rupert Bates @ 5:47 pm

Here’s a utility factory class to create an HtmlHelper instance so that you can unit test extension methods written on it. It will take a controller and a model for methods which rely on those. I adapted it from this post, and changed it to work with Asp.Net version 1.0 and to accept a model.

using System;
using System.Web;
using System.Web.Mvc;
using System.Web.Routing;
using KableDirect.Web.FrontEnd.Controllers;

namespace KableDirect.UnitTests
{
    class HtmlHelperFactory
    {
        public static HtmlHelper CreateInstance(RouteData route)
        {
            return CreateInstance(route, new HomeController());
        }
        public static HtmlHelper CreateInstance(RouteData route, Controller controller)
        {
            return CreateInstance(route, controller, null);
        }
        public static HtmlHelper CreateInstance(RouteData route, Controller controller, object model)
        {
            HttpContextBase httpContext = new HttpContextDummy();

            var cc = new ControllerContext(httpContext, route, controller);
            var vd = new ViewDataDictionary(model);
            ViewContext vc = new ViewContext(cc, new ViewDummy(), vd, new TempDataDictionary());
            return new HtmlHelper(vc, new ViewDataContainerDummy(vd), new RouteCollection());
        }


        // Dummy classes needed to be able to create HtmlHelper

        private class HttpRequestDummy : HttpRequestBase
        {
            public override string ApplicationPath
            {
                get { return ""; }
            }

            public override string AppRelativeCurrentExecutionFilePath
            {
                // Any shorter string here gives exception:
                // index larger than length of string
                get { return "~/"; }
            }

            public override string PathInfo
            {
                get { return ""; }
            }
        }

        private class HttpResponseDummy : HttpResponseBase
        {
            public override string ApplyAppPathModifier(string virtualPath)
            {
                return virtualPath;
            }
        }

        private class HttpContextDummy : HttpContextBase
        {
            public override HttpRequestBase Request
            {
                get { return new HttpRequestDummy(); }
            }

            public override HttpResponseBase Response
            {
                get { return new HttpResponseDummy(); }
            }
        }

        private class ViewDummy : IView
        {
            public void Render(ViewContext viewContext, System.IO.TextWriter writer)
            {
                throw new NotImplementedException();
            }
        }

        private class ViewDataContainerDummy : IViewDataContainer
        {
            public ViewDataContainerDummy()
            {
            }

            public ViewDataContainerDummy(ViewDataDictionary dataDictionary)
            {
                _data = dataDictionary;
            }

            private ViewDataDictionary _data;
            public ViewDataDictionary ViewData
            {
                get { return _data; }
                set { _data = value; }
            }
        }
    }
}

 

 

Access RouteData for the current Route from a library class in asp.net mvc October 7, 2009

Filed under: Asp.Net,C#,MVC — Rupert Bates @ 1:20 pm

Sometimes it’s useful to be able to access the current RouteData from outside a controller, for instance in a library class. In webforms you could always do


HttpContext.Current

but in Asp.Net MVC it’s a bit less obvious how you get access to this data.

I’ve found the following code works:


RouteTable.Routes.GetRouteData(new HttpContextWrapper(HttpContext.Current));

Whether there is an easier way or not I don’t know, but this will do me for now…

 

Group By with Count in Linq September 29, 2009

Filed under: C#,Linq — Rupert Bates @ 8:26 pm

To group a sequence getting a count for each element of the grouped sequence using Linq:

            var wordList = new List<String> { "test", "one", "test", "two" };
            var grouped = wordList
                .GroupBy(i => i) //Group the words
                .Select(i => new { Word = i.Key, Count = i.Count() }); //get a count for each

Which results in this sequence:

watch

 

 
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