/// <summary>
/// This is one of our top level node.
/// mutation MyMutation {...}
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override IGraphQLBaseNode VisitMutationQuery(EntityGraphQLParser.MutationQueryContext context)
{
//== JT: set the Operation Type
schemaProvider.OperationType = OperationType.Mutation;
//==
var operation = GetOperation(context.operationName());
foreach (var item in operation.Arguments.Where(a => a.DefaultValue != null))
{
variables[item.ArgName] = Expression.Lambda(item.DefaultValue.Expression).Compile().DynamicInvoke();
}
this.currentExpressionContext = (ExpressionResult)Expression.Parameter(schemaProvider.ContextType, $"ctx");
var mutateFields = new List <IGraphQLBaseNode>();
foreach (var c in context.objectSelection().children)
{
var n = Visit(c);
if (n != null)
{
mutateFields.Add(n);
}
}
var mutation = new GraphQLQueryNode(schemaProvider, fragments, operation.Name, null, null, mutateFields, null);
return(mutation);
}
/// <summary>
/// This is one of our top level node.
/// query MyQuery {
/// entityQuery { fields [, field] },
/// entityQuery { fields [, field] },
/// ...
/// }
/// </summary>
/// <param name="context"></param>
/// <returns></returns>
public override IGraphQLBaseNode VisitDataQuery(EntityGraphQLParser.DataQueryContext context)
{
//== JT: set the Operation Type
schemaProvider.OperationType = OperationType.Query;
//==
var operation = GetOperation(context.operationName());
foreach (var item in operation.Arguments.Where(a => a.DefaultValue != null))
{
variables[item.ArgName] = Expression.Lambda(item.DefaultValue.Expression).Compile().DynamicInvoke();
}
this.currentExpressionContext = (ExpressionResult)Expression.Parameter(schemaProvider.ContextType, $"ctx");
var rootFields = new List <GraphQLQueryNode>();
// Just visit each child node. All top level will be entityQueries
foreach (var c in context.objectSelection().children)
{
var n = Visit(c);
if (n != null)
{
rootFields.Add((GraphQLQueryNode)n);
}
}
var query = new GraphQLQueryNode(schemaProvider, fragments, operation.Name, currentExpressionContext, (ParameterExpression)currentExpressionContext, rootFields, null);
return(query);
}
public override IGraphQLBaseNode VisitField(EntityGraphQLParser.FieldContext context)
{
var fieldName = context.fieldDef.GetText();
string schemaTypeName = schemaProvider.GetSchemaTypeNameForDotnetType(currentExpressionContext.Type);
var actualFieldName = schemaProvider.GetActualFieldName(schemaTypeName, fieldName, claims);
var args = context.argsCall != null?ParseGqlCall(actualFieldName, context.argsCall) : null;
var alias = context.alias?.name.GetText();
//== JT: add Operation Type check
if (schemaProvider.HasMutation(actualFieldName) && schemaProvider.OperationType == OperationType.Mutation)
{
var mutationType = schemaProvider.GetMutations().First(m => m.Name == actualFieldName);
if (context.select != null)
{
var expContext = (ExpressionResult)Expression.Parameter(mutationType.ReturnType.SchemaType.ContextType, $"mut_{actualFieldName}");
var oldContext = currentExpressionContext;
currentExpressionContext = expContext;
var select = ParseFieldSelect(expContext, actualFieldName, context.select);
currentExpressionContext = oldContext;
return(new GraphQLMutationNode(mutationType, args, (GraphQLQueryNode)select));
}
else
{
var resultName = alias ?? actualFieldName;
return(new GraphQLMutationNode(mutationType, args, null));
}
}
else
{
if (!schemaProvider.TypeHasField(schemaTypeName, actualFieldName, args != null ? args.Select(d => d.Key) : new string[0], claims))
{
throw new EntityGraphQLCompilerException($"Field {actualFieldName} not found on type {schemaTypeName}");
}
var result = schemaProvider.GetExpressionForField(currentExpressionContext, schemaTypeName, actualFieldName, args, claims);
IGraphQLBaseNode fieldResult;
var resultName = alias ?? actualFieldName;
if (context.select != null)
{
fieldResult = ParseFieldSelect(result, resultName, context.select);
}
else
{
fieldResult = new GraphQLQueryNode(schemaProvider, fragments, resultName, result, currentExpressionContext.AsParameter(), null, null);
}
if (context.directive != null)
{
return(ProcessFieldDirective((GraphQLQueryNode)fieldResult, context.directive));
}
return(fieldResult);
}
}
private IGraphQLBaseNode ProcessFieldDirective(GraphQLQueryNode fieldResult, EntityGraphQLParser.DirectiveCallContext directive)
{
var processor = schemaProvider.GetDirective(directive.name.GetText());
var argList = directive.directiveArgs.children.Where(c => c.GetType() == typeof(EntityGraphQLParser.GqlargContext)).Cast <EntityGraphQLParser.GqlargContext>();
var args = argList.ToDictionary(a => a.gqlfield.GetText(), a => ParseGqlarg(null, a));
var argType = processor.GetArgumentsType();
var argObj = Activator.CreateInstance(argType);
foreach (var arg in args)
{
var prop = argType.GetProperty(arg.Key);
prop.SetValue(argObj, Expression.Lambda(arg.Value.Expression).Compile().DynamicInvoke());
}
var result = processor.ProcessQueryInternal(fieldResult, argObj);
return(result);
}
/// <summary>
/// Given a syntax of { fields, to, selection, from, object } with a context
/// it will build the correct select statement
/// </summary>
/// <param name="name"></param>
/// <param name="context"></param>
/// <param name="selectContext"></param>
/// <returns></returns>
private IGraphQLBaseNode BuildDynamicSelectForObjectGraph(ExpressionResult selectFromExp, ParameterExpression selectFromParam, string name, EntityGraphQLParser.ObjectSelectionContext context)
{
try
{
// visit child fields. Will be field or entityQueries again
// These expression will be built on the element type
var oldContext = currentExpressionContext;
currentExpressionContext = selectFromExp;
var fieldExpressions = context.children.Select(c => Visit(c)).Where(n => n != null).ToList();
currentExpressionContext = oldContext;
var graphQLNode = new GraphQLQueryNode(schemaProvider, fragments, name, selectFromExp, selectFromParam, fieldExpressions, selectFromExp);
return(graphQLNode);
}
catch (EntityGraphQLCompilerException ex)
{
throw SchemaException.MakeFieldCompileError($"Failed compiling field {name}", ex.Message);
}
}
/// Given a syntax of someCollection { fields, to, selection, from, object }
/// it will build a select assuming 'someCollection' is an IEnumerables
private IGraphQLBaseNode BuildDynamicSelectOnCollection(ExpressionResult queryResult, string resultName, EntityGraphQLParser.ObjectSelectionContext context)
{
var elementType = queryResult.Type.GetEnumerableOrArrayType();
var contextParameter = Expression.Parameter(elementType, $"p_{elementType.Name}");
var exp = queryResult;
var oldContext = currentExpressionContext;
currentExpressionContext = (ExpressionResult)contextParameter;
// visit child fields. Will be more fields
var fieldExpressions = context.children.Select(c => Visit(c)).Where(n => n != null).ToList();
var gqlNode = new GraphQLQueryNode(schemaProvider, fragments, resultName, exp, oldContext.AsParameter(), fieldExpressions, (ExpressionResult)contextParameter);
currentExpressionContext = oldContext;
return(gqlNode);
}
/// <summary>
/// Given a syntax of { fields, to, selection, from, object } with a context
/// it will build the correct select statement
/// </summary>
/// <param name="name"></param>
/// <param name="context"></param>
/// <param name="selectContext"></param>
/// <returns></returns>
private IGraphQLBaseNode BuildDynamicSelectForObjectGraph(ExpressionResult selectFromExp, ParameterExpression selectFromParam, string name, EntityGraphQLParser.ObjectSelectionContext context)
{
try
{
// visit child fields. Will be field or entityQueries again
// These expression will be built on the element type
var oldContext = currentExpressionContext;
currentExpressionContext = selectFromExp;
ParameterExpression replacementParameter = null;
// we might be using a service i.e. ctx => WithService((T r) => r.DoSomething(ctx.Entities.Select(f => f.Id).ToList()))
// if we can we want to avoid calling that multiple times with a expression like
// r.DoSomething(ctx.Entities.Select(f => f.Id).ToList()) == null ? null : new {
// Field = r.DoSomething(ctx.Entities.Select(f => f.Id).ToList()).Blah
// }
// by wrapping the whole thing in a method that does the null check once.
// This means we build the fieldExpressions on a parameter of the result type
// We can only do that if it doesn't use the oldContext unless the oldContext is the root context
// i.e we can't do this on a field on a type because we don't have that value as it might be a selection from an ORM
bool wrapField = (oldContext.Type == schemaProvider.ContextType || oldContext.NodeType == ExpressionType.Parameter) && currentExpressionContext.Services.Any();
if (wrapField)
{
// replace with a parameter. The expression is compiled at execution time once
replacementParameter = Expression.Parameter(selectFromExp.Type, "null_wrap");
currentExpressionContext = (ExpressionResult)replacementParameter;
}
var fieldExpressions = context.children.Select(c => Visit(c)).Where(n => n != null).ToList();
currentExpressionContext = oldContext;
var graphQLNode = new GraphQLQueryNode(schemaProvider, fragments, name, selectFromExp, selectFromParam, fieldExpressions, selectFromExp)
{
IsWrapped = wrapField
};
return(graphQLNode);
}
catch (EntityGraphQLCompilerException ex)
{
throw SchemaException.MakeFieldCompileError($"Failed compiling field {name}", ex.Message);
}
}
