/// 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);
}
public override IGraphQLBaseNode VisitField(EntityGraphQLParser.FieldContext context)
{
var name = baseIdentityFinder.Visit(context);
var result = EqlCompiler.CompileWith(context.GetText(), selectContext, schemaProvider, methodProvider, variables);
var actualName = schemaProvider.GetActualFieldName(schemaProvider.GetSchemaTypeNameForRealType(selectContext.Type), name);
var node = new GraphQLNode(schemaProvider, fragments, actualName, result, null);
return(node);
}
/// 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);
}
}
public override IGraphQLNode VisitMutationQuery(EntityGraphQLParser.MutationQueryContext context)
{
var root = new GraphQLNode("root", null, null, null, null);
var operationName = GetOperationName(context.operationName());
foreach (var c in context.gqlBody().children)
{
var mutation = Visit(c);
if (mutation != null)
{
root.Fields.Add(mutation);
}
}
return(root);
}
/// This is our top level node.
/// {
/// entityQuery { fields [, field] },
/// entityQuery { fields [, field] },
/// ...
/// }
public override IGraphQLNode VisitDataQuery(EntityGraphQLParser.DataQueryContext context)
{
var root = new GraphQLNode("root", null, null, null, null);
var operationName = GetOperationName(context.operationName());
// Just visit each child node. All top level will be entityQueries
foreach (var c in context.gqlBody().children)
{
var n = Visit(c);
if (n != null)
{
root.Fields.Add(n);
}
}
return(root);
}
/// 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);
}
}
public override IGraphQLBaseNode VisitAliasExp(EntityGraphQLParser.AliasExpContext context)
{
var name = context.alias.name.GetText();
var query = context.entity.GetText();
if (selectContext == null)
{
// top level are queries on the context
var exp = EqlCompiler.Compile(query, schemaProvider, methodProvider, variables);
var node = new GraphQLNode(schemaProvider, fragments, name, exp, null);
return(node);
}
else
{
var result = EqlCompiler.CompileWith(query, selectContext, schemaProvider, methodProvider, variables);
var node = new GraphQLNode(schemaProvider, fragments, name, result, null);
return(node);
}
}
/// 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);
}
/// <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)
{
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();
}
var mutation = new GraphQLNode(schemaProvider, fragments, operation.Name, null, null, null, null, null);
foreach (var c in context.gqlBody().children)
{
var n = Visit(c);
if (n != null)
{
mutation.AddField((IGraphQLNode)n);
}
}
rootQueries.Add(mutation);
return(mutation);
}
