Package graphql.analysis

Class QueryTransformer

java.lang.Object

graphql.analysis.QueryTransformer

@PublicApi
public class QueryTransformer
extends java.lang.Object

Helps to transform a Document (or parts of it) and tracks at the same time the corresponding Schema types.

This is an important distinction to just traversing the Document without any type information: Each field has a clearly defined type. See QueryVisitorFieldEnvironment.

Furthermore are the built in Directives skip/include automatically evaluated: if parts of the Document should be ignored they will not be visited. But this is not a full evaluation of a Query: every fragment will be visited/followed regardless of the type condition.

It also doesn't consider field merging, which means for example { user{firstName} user{firstName}} will result in four visitField calls.

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	QueryTransformer.Builder

Method Summary

Modifier and Type	Method	Description
static QueryTransformer.Builder	newQueryTransformer()
Node	transform(QueryVisitor queryVisitor)	Visits the Document in pre-order and allows to transform it using TreeTransformerUtil methods.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Method Detail

transform

public Node transform(QueryVisitor queryVisitor)

Visits the Document in pre-order and allows to transform it using TreeTransformerUtil methods. Please note that fragment spreads are not followed and need to be processed explicitly by supplying them as root.

Parameters:

queryVisitor - the query visitor that will be called back.

Returns:

changed root

Throws:

java.lang.IllegalArgumentException - if there are multiple root nodes.

newQueryTransformer

public static QueryTransformer.Builder newQueryTransformer()