This simple console app generates C# GraphQL query builder and data classes for simple, compiler checked, usage of GraphQL API.
GraphQlClientGenerator <GraphQlServiceUrl> <TargetFileName> <TargetNamespace>
Installation:
Install-Package GraphQlClientGenerator
Code example for class generation:
var schema = await GraphQlGenerator.RetrieveSchema(Url);
var builder = new StringBuilder();
GraphQlGenerator.GenerateQueryBuilder(schema, builder);
GraphQlGenerator.GenerateDataClasses(schema, builder);
var generatedClasses = builder.ToString();var builder =
new QueryQueryBuilder()
.WithMe(
new MeQueryBuilder()
.WithAllScalarFields()
.WithHome(
new HomeQueryBuilder()
.WithAllScalarFields()
.WithSubscription(
new SubscriptionQueryBuilder()
.WithStatus()
.WithValidFrom())
.WithSignupStatus(
new SignupStatusQueryBuilder().WithAllFields())
.WithDisaggregation(
new DisaggregationQueryBuilder().WithAllFields()),
"b420001d-189b-44c0-a3d5-d62452bfdd42")
.WithEnergyStatements ("2016-06", "2016-10"));
var query = builder.Build(Formatting.Indented);results into
{
me {
id
firstName
lastName
fullName
ssn
email
language
tone
home (id: "b420001d-189b-44c0-a3d5-d62452bfdd42") {
id
avatar
timeZone
subscription {
status
validFrom
}
signupStatus {
registrationStartedTimestamp
registrationCompleted
registrationCompletedTimestamp
checkCurrentSupplierPassed
supplierSwitchConfirmationPassed
startDatePassed
firstReadingReceived
firstBillingDone
firstBillingTimestamp
}
disaggregation {
year
month
fixedConsumptionKwh
fixedConsumptionKwhPercent
heatingConsumptionKwh
heatingConsumptionKwhPercent
behaviorConsumptionKwh
behaviorConsumptionKwhPercent
}
}
energyStatements(from: "2016-06", to: "2016-10")
}
}
var mutation =
new RootMutationQueryBuilder()
.WithUpdateHome(
new HomeQueryBuilder().WithAllScalarFields(),
new UpdateHomeInput { HomeId = Guid.Empty, AppNickname = "My nickname", Type = HomeType.House, NumberOfResidents = 4, Size = 160, AppAvatar = HomeAvatar.Floorhouse1, PrimaryHeatingSource = HeatingSource.Electricity }
)
.Build(Formatting.Indented, 2);result:
mutation {
updateHome (input: {
homeId: "00000000-0000-0000-0000-000000000000"
appNickname: "My nickname"
appAvatar: FLOORHOUSE1
size: 160
type: HOUSE
numberOfResidents: 4
primaryHeatingSource: ELECTRICITY
}) {
id
timeZone
appNickname
appAvatar
size
type
numberOfResidents
primaryHeatingSource
hasVentilationSystem
}
}
GraphQL supports custom scalar types. By default these are mapped to object type. To ensure appropriate .NET types are generated for data class properties custom mapping function can be used:
GraphQlGeneratorConfiguration.CustomScalarFieldTypeMapping =
(baseType, valueType, valueName) =>
{
valueType = valueType is GraphQlFieldType fieldType ? fieldType.UnwrapIfNonNull() : valueType;
// DateTime and Byte
switch (valueType.Name)
{
case "Byte":
return "byte?";
case "DateTime":
return "DateTime?";
}
// fallback - not needed if you cover all possible cases or you are ok with object type
return GraphQlGeneratorConfiguration.DefaultScalarFieldTypeMapping(baseType, valueType, valueName);
};Generated class example:
public class OrderType
{
public DateTime? CreatedDateTimeUtc { get; set; }
public byte? SomeSmallNumber { get; set; }
}vs.
public class OrderType
{
public object CreatedDateTimeUtc { get; set; }
public object SomeSmallNumber { get; set; }
}