Indexes: Additional Assemblies

Additional assemblies are defined using the AdditionalAssembly object.

public class AdditionalAssembly
{
    public static AdditionalAssembly FromRuntime(string assemblyName, 
                                                 HashSet<string> usings = null);

    public static AdditionalAssembly FromPath(string assemblyPath, 
                                              HashSet<string> usings = null);

    public static AdditionalAssembly FromNuGet(string packageName, 
                                               string packageVersion, 
                                               string packageSourceUrl = null, 
                                               HashSet<string> usings = null);
}

The AdditionalAssemblys are collected in AdditionalAssemblies, a property of IndexDefinition:

public HashSet<AdditionalAssembly> AdditionalAssemblies;

Basic example

This index is able to use the method GetFileName() from the class Path because the namespace System.IO has been imported as an additional assembly. It takes a string file path and retrieves just the file name and extension.

var runtimeindex = new IndexDefinition
{
    Name = "Dog_Pictures",
    Maps = { @"
        from user in docs.Users
        let fileName = Path.GetFileName(user.ImagePath)
        where fileName = ""My_Dogs.jpeg""
        select new {
            user.Name,
            fileName
        }"
    },
    AdditionalAssemblies = {
        AdditionalAssembly.FromRuntime("System.IO")
    }
};

Complex example

This index uses a machine learning algorithm imported from NuGet that can recognize the contents of images and classify them with an appropriate tag. These tags are then stored in the index just like any other term.

store.Maintenance.Send(new PutIndexesOperation(new IndexDefinition
{
    Name = "Photographs/Tags",
    Maps =
    {
        @"
        from p in docs.Photographs
        let photo = LoadAttachment(p, ""photo.png"")
        where photo != null
        let classified =  ImageClassifier.Classify(photo.GetContentAsStream())
        select new {
            e.Name,
            Tag = classified.Where(x => x.Value > 0.75f).Select(x => x.Key),
            _ = classified.Select(x => CreateField(x.Key, x.Value))
        }"
    },
    AdditionalSources = new System.Collections.Generic.Dictionary<string, string>
    {
        {
            "ImageClassifier", 
            @"
            public static class ImageClassifier
            {
                public static IDictionary<string, float> Classify(Stream s)
                {
                    // returns a list of descriptors with a
                    // value between 0 and 1 of how well the
                    // image matches that descriptor.
                }
            }"
        }

    },
    AdditionalAssemblies =
    {
        AdditionalAssembly.FromRuntime("System.Memory"),
        AdditionalAssembly.FromNuGet("System.Drawing.Common", "4.7.0"),
        AdditionalAssembly.FromNuGet("Microsoft.ML", "1.5.2")
    }
}));