System.Text.Json support for Microsoft.Spatial library for .NET

Article
10/11/2022

The Microsoft.Spatial package contains classes and methods that support geographic operations. This library contains converters dependent on System.Text.Json for use with Microsoft.Spatial when using the Azure SDK for .NET.

Getting started

Install this package if you use the Microsoft.Spatial package in your application and want to serialize supported classes with System.Text.Json.

Install the package

Install this package from NuGet using the .NET CLI:

dotnet add package Microsoft.Azure.Core.Spatial

Key concepts

This support package contains the MicrosoftSpatialGeoJsonConverter class which can be added to JsonSerializerOptions to deserialize geographic objects like GeographyPoint. This converter can be used with Azure SDK client libraries as shown in examples below.

Examples

The Azure.Search.Documents package is used in examples to show how search results containing geographic points can be deserialized. For more information and examples using Azure.Search.Documents, see its README.

Deserializing documents

Consider a model class containing information about mountains:

public class Mountain
{
    [SimpleField(IsKey = true)]
    public string Id { get; set; }

    [SearchableField(IsSortable = true, AnalyzerName = LexicalAnalyzerName.Values.EnLucene)]
    public string Name { get; set; }

    [SimpleField(IsFacetable = true, IsFilterable = true)]
    public GeographyPoint Summit { get; set; }
}

Adding the MicrosoftSpatialGeoJsonConverter class to serializer options will correctly deserialize the summit location:

// Get the Azure Cognitive Search endpoint and read-only API key.
Uri endpoint = new Uri(Environment.GetEnvironmentVariable("SEARCH_ENDPOINT"));
AzureKeyCredential credential = new AzureKeyCredential(Environment.GetEnvironmentVariable("SEARCH_API_KEY"));

// Create serializer options with our converter to deserialize geographic points.
JsonSerializerOptions serializerOptions = new JsonSerializerOptions
{
    Converters =
    {
        new MicrosoftSpatialGeoJsonConverter()
    },
    PropertyNamingPolicy = JsonNamingPolicy.CamelCase
};

SearchClientOptions clientOptions = new SearchClientOptions
{
    Serializer = new JsonObjectSerializer(serializerOptions)
};

SearchClient client = new SearchClient(endpoint, "mountains", credential, clientOptions);
Response<SearchResults<Mountain>> results = client.Search<Mountain>("Rainier");

foreach (SearchResult<Mountain> result in results.Value.GetResults())
{
    Mountain mountain = result.Document;
    Console.WriteLine("https://www.bing.com/maps?cp={0}~{1}&sp=point.{0}_{1}_{2}",
        mountain.Summit.Latitude,
        mountain.Summit.Longitude,
        Uri.EscapeUriString(mountain.Name));
}

If searching an index full of mountains, the following may be printed:

https://www.bing.com/maps?cp=46.85287~-121.76044&sp=point.46.85287_-121.76044_Mount%20Rainier

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.microsoft.com.

When you submit a pull request, a CLA-bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., label, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repositories using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact opencode@microsoft.com with any additional questions or comments.

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