graphql-netstandard-client

A simple and testable GraphQL client for .NET and .NET core. Thank you to bkniffler for providing the template for some of this!

Now supports Source Link for easy debugging!

To use reference the GraphQl.NetStandard.Client package on NuGet

An example request to read some basic repository information from GitHub

The example assumes the Repository type is defined as it is here

var login = "";
var gitHubAuthToken = "";
var githubGraphQLApiUrl = "https://api.github.com/graphql";

// These are added on each request so you can safely use an HttpClient instance that is 
// shared across your application
var requestHeaders = new NameValueCollection();
requestHeaders.Add( "Authorization", $"Bearer {gitHubAuthToken}");
requestHeaders.Add( "User-Agent", "graphql-netstandard-client" );

IGraphQLClient graphQLClient = new GraphQLClient(new HttpClient(), githubGraphQLApiUrl, requestHeaders);

var query = @"
query ($login: String!) {
  organization(login: $login) {
    teams(first: 2) {
      nodes {        
        name
        // Use this object if you just want the list of child objects
        repositories(first:1){
          nodes{
            name
          }
        }
        // Use this object if you want the relationship information between parent and children
        repositoryEdges: repositories(first: 1) {
          edges {
            permission
            repository: node{
              name
            }
          }
        }
      }
      pageInfo {
        endCursor
        hasNextPage
      }
    }
  }
}
";

var variables = new { login = login}

// Have the client do the deserialization
var repository = await graphQLClient.QueryAsync<Repository>(query, variables);

// Get the raw response body string
var responseBodySTring = await graphQLClient.QueryAsync(query, variables);

Handling response collections

Accomodating the way GraphQl returns collections (nodes and edges) can be difficult when deserializing into a .NET object. To accomplish this with this client see the sections below

Nodes

You can use the GraphQlNodesParent<T> and GraphQlNodesParentConverter<T> classes when defining the DTOs you want to deserialize your GraphQl response nodes into. E.G. In the example code above the Team DTO is defined as follows

public class Team
{
    [JsonConverter(typeof(GraphQlNodesParentConverter<Repository>))]
    public GraphQlNodesParent<Repository> Repositories { get; set; }
}

This results in the Repositories object having the following child properties populated which match the way GraphQl returns collections, which saves you from having to define this properties yourself for every collection.

• TotalCount
• PageInfo
• Nodes (A List<Repository> in this example)

Edges

Edges are a little more complicated as you don't just have a list of child objects, you have an object inbetween describing the relationship between the parent and child objects.

First create a class representing this in between edge object. The following class can be used to get the edge information for the Team -> Repository relationship from the GitHub GraphQL API.

public class TeamToRepositoryEdge
{
    public string Permission { get; set; }
    public Repository Repository { get; set; }
}

Then you can use this class with the GraphQlEdgesParent<T> and GraphQlEdgesParentConverter<T> classes to describe the list of edges you want to deserialize E.G. In the example code above the Team DTO is defined as follows

public class Team
{
    [JsonConverter(typeof(GraphQlEdgesParentConverter<TeamToRepositoryEdge>))]
    // This property name must match an aliased GraphQl node in your query 
    // (I.E. you'll have alias the `edge` node to match the name of this property)
    public GraphQLEdgesParent<TeamToRepositoryEdge> RepositoryEdges { get; set; }
}

This results in the RepositoryEdges object having the following child properties.

• TotalCount
• PageInfo
• Edges (A List<TeamToRepositoryEdge> in this example)