Sitecore7 Linq to Sitecore only works with SearchResultItem but not with Custom Mapped Class - linq

Question

I have this very weird problem that I cannot get my head around. Perhaps someone could point out what I am doing wrong.
Basically, I am just trying to search items using Linq to Sitecore.
So, my classes look like ( I am using glass too)
[SitecoreType(TemplateId = "{TEMPLATE_GIUD}")]
public class MyMappedClass : SharedFieldClass
{
[SitecoreField(FieldName = "mylist")]
public virtual IEnumerable<SharedFieldClass> MyMultilistField { get; set; }
[SitecoreField(FieldName = "field1")]
[IndexField("field1")]
public virtual MyKeyValue field1 { get; set; }
}
[SitecoreType]
public class MyKeyValue
{
public virtual Sitecore.Data.ID Id {get;set;}
public virtual string MyValue{get;set;}
}
So when I do the below query it works as it's supposed to.
var results = context.GetQueryable<SearchResultItem>()
.Where(c => ((string)c["field1"]) == "{GUID}").GetResults();
But, when I do the below it returns 0 result.
List<MyMappedClass> results = context.GetQueryable<MyMappedClass>()
.Where(c => c.field1.MyValue == "{GUID}").ToList();
I have read this link . And I have followed the 2nd process described here for Glass to work with Sitecore7 Search (the "SharedFieldClass" contains all the basic index fields).
This is a pretty obvious scenario and I'm sure lots of people have done it already and I am doing something silly here.
Thanks in advance.
/## EDIT ##/
Okay so I've done a bit more digging on this. Not sure if it's a bug in ContentSearch/Luncene.NET API or I am missing something BUT seems like what was posted here is probably not TRUE and if you have a complex field type ( which you will ) you can not query with a mapped class against Lucene. ( not sure if this is also the case for Solr). If you are doing search against simple type like string and int then it works like a charm.
SO here're my findings:
After enabling DEBUG and LOG on for contentsearch I found that if I query like this context.GetQueryable<MyMappedClass>().Where(c => c.field1.MyValue == "{GUID}") what it gets translated into is DEBUG Executing lucene query: field1.value:7e9ed2ae07194d83872f9836715eca8e and as there's no such thing in the index named "field1.value" the query doesn't return anything. The name of the index is actually just "field1". Is this a bug ??
However, query like this context.GetQueryable<SearchResultItem>() .Where(c => ((string)c["field1"]) == "{GUID}").GetResults(); works because it gets translated into "DEBUG Executing lucene query: +field1:7e9ed2ae07194d83872f9836715eca8e".
I also did write a method in my mapped class like below:
public string this[string key]
{
get
{
return key.ToLowerInvariant();
}
set { }
}
Which allowed me write the below query with my MyMappedClass.
results2 = context.GetQueryable<MyMappedClass>().Where(c => c["filed1"]== "{GUID}").ToList();
This returned expected result. BUT the values of the fields in MyMappedClass are not filled ( in fact they're all null except the core/shared values like templateid, url etc which are populated in the filled document). So the result list are pretty much useless. I could do a loop over all of them and manually get the values populated as I have the itemid. But imagine the cost for a large result set.
Lastly I did this:
<fieldType fieldTypeName="droplink" storageType="YES" indexType="TOKENIZED" vectorType="NO" boost="1f" type="System.String" settingType="Sitecore.ContentSearch.LuceneProvider.LuceneSearchFieldConfiguration, Sitecore.ContentSearch.LuceneProvider" />
So this returned populated "field1" with the itemid in lucene query using "IndexViewer2.0". BUT this fails for MyMappedClass too as the value of "field1" in the document is a System.string .. but it is mapped as "MyKeyValue" in MyMappedClass SO it throws the below exception
Exception: System.InvalidCastException
Message: Invalid cast from 'System.String' to 'MyLib.MyKeyValue'.
SO, the big question is:
How does one query using his/her mapped class using the cool ContentSearch API ?

Answer 1

I bit more further digging got me to a working solution. Posting it here just in case anyone runs into this issue.
This is how my "SharedFieldClass" looked like ( which was somewhat wrong )
public abstract class SharedFieldClass
{
[SitecoreId]
[IndexField("_id")]
[TypeConverter(typeof(IndexFieldIDValueConverter))]
public virtual ID Id { get; set; }
[SitecoreInfo(SitecoreInfoType.Language)]
[IndexField("_language")]
public virtual string Language { get; set; }
[SitecoreInfo(SitecoreInfoType.Version)]
public virtual int Version
{
get
{
return Uri == null ? 0 : Uri.Version.Number;
}
}
[TypeConverter(typeof(IndexFieldItemUriValueConverter))]
[XmlIgnore]
[IndexField("_uniqueid")]
public virtual ItemUri Uri { get; set; }
}
And there's a class in Glass that does the mapping. Which looks like below:
var sitecoreService = new SitecoreService("web");
foreach (var r in results)
{
sitecoreService.Map(r);
}
for me this class was failing to map because of this line:
[SitecoreId]
[IndexField("_id")]
[TypeConverter(typeof(IndexFieldIDValueConverter))]
public virtual ID Id { get; set; }
It was throwing a NULL exception at sitecoreService.Map(r); line
So I changed it to below:
[SitecoreId]
[IndexField("_group")]
[TypeConverter(typeof(IndexFieldIDValueConverter))]
public virtual ID Id { get; set; }
And it worked. I'm not sure when the index field for ItemId in sitecore changed from "_id" to "_group" or whether it was always like that. But it is "_group" in the SearchResultItem class. So I used it and mapping was successful.
So to Sum it all the solution looks like this:
The Mapped Class:
[SitecoreType(TemplateId = "{TEMPLATE_GIUD}")]
public class MyMappedClass : SharedFieldClass
{
[SitecoreField(FieldName = "mylist")]
public virtual IEnumerable<SharedFieldClass> MyMultilistField { get; set; }
[SitecoreField(FieldName = "field1")]
[IndexField("field1")]
public virtual MyKeyValue field1 { get; set; }
// Will be set with key and value for each field in the index document
public string this[string key]
{
get
{
return key.ToLowerInvariant();
}
set { }
}
}
[SitecoreType]
public class MyKeyValue
{
public virtual Sitecore.Data.ID Id {get;set;}
public virtual string MyValue{get;set;}
}
And the query is:
List<MyMappedClass> results = context.GetQueryable<MyMappedClass>()
.Where(c => c["field1"] == "{GUID}").ToList();
That's it.
/* edited */
OH!! Wait that's not it. This will still fail to cast the complex type "MyKeyValue" when the "field1" is populated with guid in the index document.
So to avoid this I had to write my custom converter as #Michael Edwards suggested.
I had to modify the class slightly to fit my needs ..
public class IndexFieldKeyValueModelConverter : TypeConverter
{
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
var config = Glass.Mapper.Context.Default.GetTypeConfiguration<SitecoreTypeConfiguration>(sourceType, true);
if (config != null && sourceType == typeof(MyLib.IKeyValue))
{
return true;
}
else
return base.CanConvertFrom(context, sourceType);
}
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
{
if (destinationType == typeof(string))
return true;
else
return base.CanConvertTo(context, destinationType);
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
var scContext = new SitecoreContext();
Guid x = Guid.Empty;
if(value is string)
{
x = new Guid((string)value);
}
var item = scContext.Database.GetItem(x.ToString());
if (item == null)
return null;
return scContext.CreateType(typeof(MyLib.IKeyValue), item, true, false, new Dictionary<string, object>());
}
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
{
var config = Glass.Mapper.Context.Default.GetTypeConfiguration<SitecoreTypeConfiguration>(value.GetType(), true);
ID id = config.GetId(value);
return id.ToShortID().ToString().ToLowerInvariant();
}
}
Not sure if it were the expected behaviour or not .. but for some reason, in the convertfrom method the value of the "object value" parameter was short string id format. So for scContext.Database.GetItem to work I had to convert it to a proper GUID and then it started returning proper item rather than null.
AND then I wrote my query like this:
results = context.GetQueryable<MyMappedGlassClass>().Where(c => c["field1"] == field1value && c["field2"] == field2value && c["_template"] == templateId).Filter(selector => selector["_group"] != currentId).ToList();
Looks like a fair bit of work to get it to work. I guess using the LinqHelper.CreateQuery method is the easy way out .. but as Mr. Pope suggested here that this method is not be used as this is an internal method.
Not sure what's the balance here.
/* end edited */
Please see my question description section for explanation on why I had to do things this way.
Also, (I bias opinion ) is the trick described here may not be valid anymore (please see my question description's edit section for the reason behind).
Also, index field for itemid in the Glass Mapper tutorial here is I think wrong (unless otherwise proven).
Hope it helps someone saving/wasting time.

Answer 2

You could create a custom field mapper for lucene that would convert from the Guid in the index to a glass model. I hacked this out but I haven't tested it:
public class IndexFieldDateTimeValueConverter : TypeConverter
{
public Type RequestedType { get; set; }
public override bool CanConvertFrom(ITypeDescriptorContext context, Type sourceType)
{
var config = Glass.Mapper.Context.Default.GetTypeConfiguration<SitecoreTypeConfiguration>(sourceType, true);
if (config != null)
{
RequestedType = sourceType;
return true;
}
else
return base.CanConvertFrom(context, sourceType);
}
public override bool CanConvertTo(ITypeDescriptorContext context, Type destinationType)
{
if (destinationType == typeof(string))
return true;
else
return base.CanConvertTo(context, destinationType);
}
public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
{
var scContext = new SitecoreContext();
return scContext.CreateType(RequestedType, scContext.Database.GetItem(value.ToString()),true, false, new Dictionary<string, object>());
}
public override object ConvertTo(ITypeDescriptorContext context, CultureInfo culture, object value, Type destinationType)
{
var config = Glass.Mapper.Context.Default.GetTypeConfiguration<SitecoreTypeConfiguration>(value.GetType(), true);
ID id =config.GetId(value);
return id.ToShortID().ToString().ToLowerInvariant();
}
My concern is that the ConvertFrom method does not get passed the type requested so we have to store this as property on the class to pass it from the CanConvertFrom method to the ConvertFrom method. This makes this class not thread safe.
Add this to the indexFieldStorageValueFormatter section of the sitecore config.

Answer 3

The problem here is that SearchResultItem is not actually an Item, but does have the GetItem() method to get the Sitecore item. What you need to do is the following:
List<MyMappedClass> results = context.GetQueryable<SearchResultItem>()
.Select(sri => sri.GetItem())
.Where(i => i != null)
.Select(i => i.GlassCast<MyMappedClass>())
.Where(c => c.field1.MyValue == "{GUID}").ToList();

Answer 4

I haven't worked with Glass specifically, but if you change your parent class to SearchResultItem, does it begin working? If so, that would indicate an issue with the SharedFieldClass parent class.