Azure Search and Date field filtering

Question

I'm using 8.2 Update-3 and have deployed it to Azure with Sitecore's ARM template.

I have indexed a page called Event Page. The Event Page has a DateTime field called Start Date on it. It is indexed as an Edm.DateTimeOffset field. I have mapped the index to a custom SearchResultItem called EventItem. The EventItem looks like this:

public class EventItem : IndexedItem
{
    [IndexField(Constants.IndexFields.Header)]
    public string Header { get; set; }

    [IndexField(Constants.IndexFields.Content)]
    public override string Content { get; set; }

    [IndexField(Constants.IndexFields.StartDate)]
    public DateTimeOffset StartDate { get; set; }
}

I want to search for all events that has a Start Date in the future:

using (var context = this.SearchIndexResolver.GetIndex("my_index").CreateSearchContext())
{
    var queryable = this.CreateAndInitializeQuery(context);

    queryable = queryable.OrderBy(x => x.StartDate);

    var dateTime = new DateTimeOffset(DateTime.UtcNow);
    queryable = queryable.Where(x => x.StartDate >= dateTime);

    var results = queryable.GetResults();

    return results;
}

This gives me the search result that I want. If I stick a breakpoint on the results variable I can see that there are 3 hits which is correct. However, when I use the mapped EventItem's from the search result I get the following exception:

[NotSupportedException: IndexFieldUtcDateTimeOffsetValueConverter cannot convert from System.DateTime.]
   System.ComponentModel.TypeConverter.GetConvertFromException(Object value) +184
   System.ComponentModel.TypeConverter.ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, Object value) +8035992
   Sitecore.ContentSearch.Azure.Converters.CloudIndexFieldStorageValueFormatter.ReadFromIndexStorageBase(Object indexValue, String fieldName, Type destinationType) +596
   Sitecore.ContentSearch.Azure.Converters.CloudIndexFieldStorageValueFormatter.ReadFromIndexStorage(Object indexValue, String fieldName, Type destinationType) +234
   Sitecore.ContentSearch.DocumentTypeMapInfo.SetProperty(Object target, String propertyName, String documentFieldName, Object value) +801
   Sitecore.ContentSearch.DefaultDocumentMapper`1.MapFieldValuesToType(IDictionary`2 fieldValues, TElement result, DocumentTypeMapInfo documentTypeMapInfo) +1789
   Sitecore.ContentSearch.DefaultDocumentMapper`1.MapToType(TDocument document, SelectMethod selectMethod, IEnumerable`1 virtualFieldProcessors, IEnumerable`1 executionContexts, SearchSecurityOptions securityOptions) +760
   Sitecore.ContentSearch.Azure.Query.CloudSearchResults`1.Map(IDictionary`2 fields) +813
   Sitecore.ContentSearch.Azure.Query.<GetSearchHits>d__13.MoveNext() +366

I have tried changing my EventItem type to a DateTime instead of DateTimeOffset and query with a DateTime.Now but that gives me a "Specified cast is not valid" exception when it comes the the GetResults() method:

[InvalidCastException: Specified cast is not valid.]
   Sitecore.ContentSearch.Azure.Query.Operations.PrepareValue(Object value, String edmType) +201
   Sitecore.ContentSearch.Azure.Query.CloudQueryMapper.HandleGreaterThanOrEqual(String srcFieldName, Object value, Single boost) +244
   Sitecore.ContentSearch.Azure.Query.CloudQueryMapper.HandleGreaterThanOrEqual(GreaterThanOrEqualNode node, CloudQueryMapperState state) +147
   Sitecore.ContentSearch.Azure.Query.CloudQueryMapper.HandleWhere(WhereNode node, CloudQueryMapperState mappingState) +37
   Sitecore.ContentSearch.Azure.Query.CloudQueryMapper.MapQuery(IndexQuery query) +64
   Sitecore.ContentSearch.Linq.Parsing.GenericQueryable`2.GetQuery(Expression expression) +271
   Sitecore.ContentSearch.Linq.Parsing.GenericQueryable`2.Execute(Expression expression) +37
   Sitecore.ContentSearch.Linq.QueryableExtensions.GetResults(IQueryable`1 source) +334

So how do I fix this? What am I doing wrong?

Answer 1

I have been digging a little further. As the stacktrace says the issue lies in the IndexFieldUtcDateTimeOffsetValueConverter. So I reflected on Sitecore.ContentSearch.Azure.Converters.IndexFieldUtcDateTimeOffsetValueConverter, Sitecore.ContentSearch.Azure and created my own implementation of the TypeConverter. The issue lies in the ConvertFrom method in the System.ComponentModel.TypeConverter class. So an override of the ConvertFrom method fixed the issue:

using Sitecore.ContentSearch.Converters;
using System;
using System.ComponentModel;
using System.Globalization;

public class IndexFieldUtcDateTimeOffsetValueConverter : AbstractTypeConverter
{
    public override object ConvertFrom(ITypeDescriptorContext context, CultureInfo culture, object value)
    {
        DateTime dateTimeValue = DateTime.MinValue;
        bool success = value != null && DateTime.TryParse(value.ToString(), out dateTimeValue);

        if (success)
        {
            return new DateTimeOffset(dateTimeValue);
        }

        throw GetConvertFromException(value);
    }
}

Now I am able to query on DateTimes, compare them in queries and sort on DateTimes. This fixes my problem. I'll open a ticket with Sitecore and if there is a different way of fixing this, I will update this post.

If you face the same problem and are using the above TypeConverter, remember to switch the TypeConverter with the standard Sitecore one:

<configuration xmlns:patch="http://www.sitecore.net/xmlconfig/" xmlns:set="http://www.sitecore.net/xmlconfig/set/">
<sitecore>
    <contentSearch>
        <indexConfigurations>
            <defaultCloudIndexConfiguration>
                <indexFieldStorageValueFormatter>
                    <converters>
                        <converter handlesType="System.DateTimeOffset" typeConverter="Sitecore.Foundation.Indexing.IndexFieldUtcDateTimeOffsetValueConverter, Sitecore.Foundation.Indexing" patch:instead="*[@handlesType='System.DateTimeOffset']" />
                    </converters>
                </indexFieldStorageValueFormatter>
            </defaultCloudIndexConfiguration>
        </indexConfigurations>
    </contentSearch>
</sitecore>