public static object Execute
(GraphQLSchema <TContext> schema, TContext context, GraphQLField field, ExecSelection <Info> query)
{
var mutReturn = field.RunMutation(context, query.Arguments.Values());
var queryableFuncExpr = field.GetExpression(query.Arguments.Values(), mutReturn);
var replaced = (LambdaExpression)ParameterReplacer.Replace(queryableFuncExpr, queryableFuncExpr.Parameters[0], GraphQLSchema <TContext> .DbParam);
// sniff queryable provider to determine how selector should be built
var dummyQuery = replaced.Compile().DynamicInvoke(context, null);
var queryType = dummyQuery.GetType();
var expressionOptions = schema.GetOptionsForQueryable(queryType);
if (expressionOptions.UseBaseType)
{
queryType = queryType.BaseType;
expressionOptions = schema.GetOptionsForQueryable(queryType);
}
var queryExecSelections = query.Selections.Values();
var selector = GetSelector(schema, field.Type, queryExecSelections, expressionOptions);
if (field.ResolutionType != ResolutionType.Unmodified)
{
var selectorExpr = Expression.Quote(selector);
// TODO: This should be temporary - queryable and enumerable should both work
var body = replaced.Body;
if (body.NodeType == ExpressionType.Convert)
{
body = ((UnaryExpression)body).Operand;
}
var call = Expression.Call(typeof(Queryable), "Select", new[] { field.Type.CLRType, field.Type.QueryType }, body, selectorExpr);
var expr = Expression.Lambda(call, GraphQLSchema <TContext> .DbParam);
var transformed = expr.Compile().DynamicInvoke(context);
object results;
switch (field.ResolutionType)
{
case ResolutionType.Unmodified:
throw new Exception("Queries cannot have unmodified resolution. May change in the future.");
case ResolutionType.ToList:
var list = GenericQueryableCall <IEnumerable <object> >(transformed, q => q.ToList());
results = list.Select(o => MapResults(o, queryExecSelections, schema)).ToList();
break;
case ResolutionType.FirstOrDefault:
var fod = GenericQueryableCall(transformed, q => q.FirstOrDefault());
results = MapResults(fod, queryExecSelections, schema);
break;
case ResolutionType.First:
var first = GenericQueryableCall(transformed, q => q.FirstOrDefault());
results = MapResults(first, queryExecSelections, schema);
break;
default:
throw new ArgumentOutOfRangeException();
}
return(results);
}
else
{
var invocation = Expression.Invoke(selector, replaced.Body);
var expr = Expression.Lambda(invocation, GraphQLSchema <TContext> .DbParam);
var result = expr.Compile().DynamicInvoke(context);
return(MapResults(result, queryExecSelections, schema));
}
}