public ExpressionResult GetExpressionForField(Expression context, string typeName, string fieldName, Dictionary <string, ExpressionResult> args, ClaimsIdentity claims)
{
if (!types.ContainsKey(typeName))
{
throw new EntityQuerySchemaException($"{typeName} not found in schema.");
}
var field = types[typeName].GetField(fieldName, claims);
var result = new ExpressionResult(field.Resolve ?? Expression.Property(context, fieldName), field.Services);
if (field.ArgumentTypesObject != null)
{
var argType = field.ArgumentTypesObject.GetType();
// get the values for the argument anonymous type object constructor
var propVals = new Dictionary <PropertyInfo, object>();
var fieldVals = new Dictionary <FieldInfo, object>();
// if they used AddField("field", new { id = Required<int>() }) the compiler makes properties and a constructor with the values passed in
foreach (var argField in argType.GetProperties())
{
var val = BuildArgumentFromMember(args, field, argField.Name, argField.PropertyType, argField.GetValue(field.ArgumentTypesObject));
// if this was a EntityQueryType we actually get a Func from BuildArgumentFromMember but the anonymous type requires EntityQueryType<>. We marry them here, this allows users to EntityQueryType<> as a Func in LINQ methods while not having it defined until runtime
if (argField.PropertyType.IsConstructedGenericType && argField.PropertyType.GetGenericTypeDefinition() == typeof(EntityQueryType <>))
{
// make sure we create a new instance and not update the schema
var entityQuery = Activator.CreateInstance(argField.PropertyType);
// set Query
var hasValue = val != null;
if (hasValue)
{
var genericProp = entityQuery.GetType().GetProperty("Query");
genericProp.SetValue(entityQuery, ((ExpressionResult)val).Expression);
}
propVals.Add(argField, entityQuery);
}
else
{
if (val != null && val.GetType() != argField.PropertyType)
{
val = ExpressionUtil.ChangeType(val, argField.PropertyType);
}
propVals.Add(argField, val);
}
}
// The auto argument is built at runtime from LinqRuntimeTypeBuilder which just makes public fields
// they could also use a custom class, so we need to look for both fields and properties
foreach (var argField in argType.GetFields())
{
var val = BuildArgumentFromMember(args, field, argField.Name, argField.FieldType, argField.GetValue(field.ArgumentTypesObject));
fieldVals.Add(argField, val);
}
// create a copy of the anonymous object. It will have the default values set
// there is only 1 constructor for the anonymous type that takes all the property values
var con = argType.GetConstructor(propVals.Keys.Select(v => v.PropertyType).ToArray());
object parameters;
if (con != null)
{
parameters = con.Invoke(propVals.Values.ToArray());
foreach (var item in fieldVals)
{
item.Key.SetValue(parameters, item.Value);
}
}
else
{
// expect an empty constructor
con = argType.GetConstructor(new Type[0]);
parameters = con.Invoke(new object[0]);
foreach (var item in fieldVals)
{
item.Key.SetValue(parameters, item.Value);
}
foreach (var item in propVals)
{
item.Key.SetValue(parameters, item.Value);
}
}
// tell them this expression has another parameter
var argParam = Expression.Parameter(argType, $"arg_{argType.Name}");
result.Expression = new ParameterReplacer().ReplaceByType(result.Expression, argType, argParam);
result.AddConstantParameter(argParam, parameters);
}
// the expressions we collect have a different starting parameter. We need to change that
var paramExp = field.FieldParam;
result.Expression = new ParameterReplacer().Replace(result.Expression, paramExp, context);
return(result);
}
public ExpressionResult GetExpressionForField(Expression context, string typeName, string fieldName, Dictionary <string, ExpressionResult> args)
{
if (!_types.ContainsKey(typeName))
{
throw new EntityQuerySchemaError($"{typeName} not found in schema.");
}
var field = _types[typeName].GetField(fieldName, args != null ? args.Select(f => f.Key).ToArray() : new string[0]);
var result = new ExpressionResult(field.Resolve ?? Expression.Property(context, fieldName));
if (field.ArgumentTypes != null)
{
var argType = field.ArgumentTypes.GetType();
// get the values for the argument anonymous type object constructor
var propVals = new Dictionary <PropertyInfo, object>();
var fieldVals = new Dictionary <FieldInfo, object>();
// if they used AddField("field", new { id = Required<int>() }) the compiler makes properties and a constructor with the values passed in
foreach (var argField in argType.GetProperties())
{
var val = BuildArgumentFromMember(args, field, argField.Name, argField.PropertyType, argField.GetValue(field.ArgumentTypes));
propVals.Add(argField, val);
}
// The auto argument is built at runtime from LinqRuntimeTypeBuilder which just makes public fields
// they could also use a custom class
foreach (var argField in argType.GetFields())
{
var val = BuildArgumentFromMember(args, field, argField.Name, argField.FieldType, argField.GetValue(field.ArgumentTypes));
fieldVals.Add(argField, val);
}
// create a copy of the anonymous object. It will have the default values set
// there is only 1 constructor for the anonymous type that takes all the property values
var con = argType.GetConstructor(propVals.Values.Select(v => v.GetType()).ToArray());
object parameters;
if (con != null)
{
parameters = con.Invoke(propVals.Values.ToArray());
foreach (var item in fieldVals)
{
item.Key.SetValue(parameters, item.Value);
}
}
else
{
// expect an empty constructor
con = argType.GetConstructor(new Type[0]);
parameters = con.Invoke(new object[0]);
foreach (var item in fieldVals)
{
item.Key.SetValue(parameters, item.Value);
}
foreach (var item in propVals)
{
item.Key.SetValue(parameters, item.Value);
}
}
// tell them this expression has another parameter
var argParam = Expression.Parameter(argType);
result.Expression = new ParameterReplacer().ReplaceByType(result.Expression, argType, argParam);
result.AddConstantParameter(argParam, parameters);
}
// the expressions we collect have a different starting parameter. We need to change that
var paramExp = field.FieldParam;
result.Expression = new ParameterReplacer().Replace(result.Expression, paramExp, context);
return(result);
}
