/// <summary> /// We compile each entityQuery with EqlCompiler and build a Select call from the fields /// </summary> /// <param name="context"></param> /// <returns></returns> public override IGraphQLBaseNode VisitEntityQuery(EntityGraphQLParser.EntityQueryContext context) { string name; string query; if (context.alias != null) { name = context.alias.name.GetText(); query = context.entity.GetText(); } else { query = context.entity.GetText(); name = query; if (name.IndexOf(".") > -1) { name = name.Substring(0, name.IndexOf(".")); } if (name.IndexOf("(") > -1) { name = name.Substring(0, name.IndexOf("(")); } } try { CompiledQueryResult result = null; if (selectContext == null) { // top level are queries on the context result = EqlCompiler.Compile(query, schemaProvider, methodProvider, variables); } else { result = EqlCompiler.CompileWith(query, selectContext, schemaProvider, methodProvider, variables); } var exp = result.ExpressionResult; IGraphQLNode graphQLNode = null; if (exp.Type.IsEnumerableOrArray()) { graphQLNode = BuildDynamicSelectOnCollection(result, name, context); } else { // Could be a list.First() that we need to turn into a select, or // other levels are object selection. e.g. from the top level people query I am selecting all their children { field1, etc. } // Can we turn a list.First() into and list.Select().First() var listExp = Compiler.Util.ExpressionUtil.FindIEnumerable(result.ExpressionResult); if (listExp.Item1 != null) { // yes we can // rebuild the ExpressionResult so we keep any ConstantParameters var item1 = (ExpressionResult)listExp.Item1; item1.AddConstantParameters(result.ExpressionResult.ConstantParameters); graphQLNode = BuildDynamicSelectOnCollection(new CompiledQueryResult(item1, result.ContextParams), name, context); graphQLNode.SetNodeExpression((ExpressionResult)Compiler.Util.ExpressionUtil.CombineExpressions(graphQLNode.GetNodeExpression(), listExp.Item2)); } else { graphQLNode = BuildDynamicSelectForObjectGraph(query, name, context, result); } } // the query result may be a mutation if (result.IsMutation) { return(new GraphQLMutationNode(result, graphQLNode)); } return(graphQLNode); } catch (EntityGraphQLCompilerException ex) { throw SchemaException.MakeFieldCompileError(query, ex.Message); } }
/// Given a syntax of someField { fields, to, selection, from, object } /// it will build the correct select statement private IGraphQLNode BuildDynamicSelectForObjectGraph(string query, string name, EntityGraphQLParser.EntityQueryContext context, CompiledQueryResult rootField) { var selectWasNull = false; if (selectContext == null) { selectContext = Expression.Parameter(schemaProvider.ContextType); selectWasNull = true; } if (schemaProvider.TypeHasField(selectContext.Type.Name, name, new string[0])) { name = schemaProvider.GetActualFieldName(selectContext.Type.Name, name); } try { var exp = (Expression)rootField.ExpressionResult; var oldContext = selectContext; var rootFieldParam = Expression.Parameter(exp.Type); selectContext = rootField.IsMutation ? rootFieldParam : exp; // visit child fields. Will be field or entityQueries again var fieldExpressions = context.fields.children.Select(c => Visit(c)).Where(n => n != null).ToList(); var graphQLNode = new GraphQLNode(schemaProvider, fragments, name, null, (ExpressionResult)selectContext, (rootField.IsMutation ? new ParameterExpression[] { rootFieldParam } : rootField.ContextParams.ToArray()), fieldExpressions, null); if (rootField != null && rootField.ConstantParameters != null) { graphQLNode.AddConstantParameters(rootField.ConstantParameters); } selectContext = oldContext; if (selectWasNull) { selectContext = null; } return(graphQLNode); } catch (EntityGraphQLCompilerException ex) { throw SchemaException.MakeFieldCompileError(query, ex.Message); } }
/// Given a syntax of someField { fields, to, selection, from, object } /// it will build the correct select statement private IGraphQLNode BuildDynamicSelectForObjectGraph(string query, string name, EntityGraphQLParser.EntityQueryContext context, QueryResult rootField) { var selectWasNull = false; if (selectContext == null) { selectContext = Expression.Parameter(schemaProvider.ContextType); selectWasNull = true; } if (schemaProvider.TypeHasField(selectContext.Type.Name, name, new string[0])) { name = schemaProvider.GetActualFieldName(selectContext.Type.Name, name); } try { Expression exp = rootField.LambdaExpression.Body; var oldContext = selectContext; var rootFieldParam = Expression.Parameter(exp.Type); selectContext = rootField.IsMutation ? rootFieldParam : exp; // visit child fields. Will be field or entityQueries again var fieldExpressions = context.fields.children.Select(c => Visit(c)).Where(n => n != null).ToList(); var newExp = ExpressionUtil.CreateNewExpression(selectContext, fieldExpressions, schemaProvider); var anonType = newExp.Type; // make a null check from this new expression if (!rootField.IsMutation) { newExp = Expression.Condition(Expression.MakeBinary(ExpressionType.Equal, selectContext, Expression.Constant(null)), Expression.Constant(null, anonType), newExp, anonType); } selectContext = oldContext; var t = MergeConstantParametersFromFields(rootField, fieldExpressions, rootFieldParam); var parameters = t.Item1; var constantParameterValues = t.Item2; var graphQLNode = new GraphQLNode(name, new QueryResult((ExpressionResult)newExp, parameters, constantParameterValues), (ExpressionResult)exp); if (selectWasNull) { selectContext = null; } return(graphQLNode); } catch (EntityGraphQLCompilerException ex) { throw SchemaException.MakeFieldCompileError(query, ex.Message); } }
/// Given a syntax of someCollection { fields, to, selection, from, object } /// it will build a select assuming 'someCollection' is an IEnumerables private IGraphQLNode BuildDynamicSelectOnCollection(CompiledQueryResult queryResult, string name, EntityGraphQLParser.EntityQueryContext context) { var elementType = queryResult.BodyType.GetEnumerableOrArrayType(); var contextParameter = Expression.Parameter(elementType, $"param_{elementType}"); var exp = queryResult.ExpressionResult; var oldContext = selectContext; selectContext = contextParameter; // visit child fields. Will be field or entityQueries again var fieldExpressions = context.fields.children.Select(c => Visit(c)).Where(n => n != null).ToList(); var gqlNode = new GraphQLNode(schemaProvider, fragments, name, null, exp, queryResult.ContextParams, fieldExpressions, contextParameter); selectContext = oldContext; return(gqlNode); }
/// Given a syntax of someCollection { fields, to, selection, from, object } /// it will build a select assuming 'someCollection' is an IEnumerables private IGraphQLNode BuildDynamicSelectOnCollection(QueryResult queryResult, string name, EntityGraphQLParser.EntityQueryContext context, bool isRootSelect) { var elementType = queryResult.BodyType.GetEnumerableType(); var contextParameter = Expression.Parameter(elementType); var exp = queryResult.LambdaExpression.Body; var oldContext = selectContext; selectContext = contextParameter; // visit child fields. Will be field or entityQueries again var fieldExpressions = context.fields.children.Select(c => Visit(c)).Where(n => n != null).ToList(); // Default we select out sub objects/relations. So Select(d => new {Field = d.Field, Relation = new { d.Relation.Field }}) var selectExpression = (ExpressionResult)ExpressionUtil.SelectDynamic(contextParameter, exp, fieldExpressions, schemaProvider); selectContext = oldContext; var t = MergeConstantParametersFromFields(queryResult, fieldExpressions, contextParameter); var parameters = t.Item1; var constantParameterValues = t.Item2; var gqlNode = new GraphQLNode(name, new QueryResult(selectExpression, parameters, constantParameterValues), (ExpressionResult)exp); return(gqlNode); }