graphql.language.AstPrinter Maven / Gradle / Ivy
package graphql.language;
import graphql.PublicApi;
import graphql.collect.ImmutableKit;
import java.io.PrintWriter;
import java.io.Writer;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import static graphql.Assert.assertShouldNeverHappen;
import static graphql.Assert.assertTrue;
import static graphql.util.EscapeUtil.escapeJsonStringTo;
/**
* This can take graphql language AST and print it out as a string
*/
@SuppressWarnings("UnnecessaryLocalVariable")
@PublicApi
public class AstPrinter {
private final Map, NodePrinter> printers = new LinkedHashMap<>();
private final boolean compactMode;
AstPrinter(boolean compactMode) {
this.compactMode = compactMode;
printers.put(Argument.class, argument());
printers.put(ArrayValue.class, value());
printers.put(BooleanValue.class, value());
printers.put(NullValue.class, value());
printers.put(Directive.class, directive());
printers.put(DirectiveDefinition.class, directiveDefinition());
printers.put(DirectiveLocation.class, directiveLocation());
printers.put(Document.class, document());
printers.put(EnumTypeDefinition.class, enumTypeDefinition());
printers.put(EnumTypeExtensionDefinition.class, enumTypeExtensionDefinition());
printers.put(EnumValue.class, enumValue());
printers.put(EnumValueDefinition.class, enumValueDefinition());
printers.put(Field.class, field());
printers.put(FieldDefinition.class, fieldDefinition());
printers.put(FloatValue.class, value());
printers.put(FragmentDefinition.class, fragmentDefinition());
printers.put(FragmentSpread.class, fragmentSpread());
printers.put(InlineFragment.class, inlineFragment());
printers.put(InputObjectTypeDefinition.class, inputObjectTypeDefinition());
printers.put(InputObjectTypeExtensionDefinition.class, inputObjectTypeExtensionDefinition());
printers.put(InputValueDefinition.class, inputValueDefinition());
printers.put(InterfaceTypeDefinition.class, interfaceTypeDefinition());
printers.put(InterfaceTypeExtensionDefinition.class, interfaceTypeExtensionDefinition());
printers.put(IntValue.class, value());
printers.put(ListType.class, type());
printers.put(NonNullType.class, type());
printers.put(ObjectField.class, objectField());
printers.put(ObjectTypeDefinition.class, objectTypeDefinition());
printers.put(ObjectTypeExtensionDefinition.class, objectTypeExtensionDefinition());
printers.put(ObjectValue.class, value());
printers.put(OperationDefinition.class, operationDefinition());
printers.put(OperationTypeDefinition.class, operationTypeDefinition());
printers.put(ScalarTypeDefinition.class, scalarTypeDefinition());
printers.put(ScalarTypeExtensionDefinition.class, scalarTypeExtensionDefinition());
printers.put(SchemaDefinition.class, schemaDefinition());
printers.put(SchemaExtensionDefinition.class, schemaExtensionDefinition());
printers.put(SelectionSet.class, selectionSet());
printers.put(StringValue.class, value());
printers.put(TypeName.class, type());
printers.put(UnionTypeDefinition.class, unionTypeDefinition());
printers.put(UnionTypeExtensionDefinition.class, unionTypeExtensionDefinition());
printers.put(VariableDefinition.class, variableDefinition());
printers.put(VariableReference.class, variableReference());
}
private NodePrinter argument() {
if (compactMode) {
return (out, node) -> {
out.append(node.getName()).append(':');
value(out, node.getValue());
};
}
return (out, node) -> {
out.append(node.getName()).append(": ");
value(out, node.getValue());
};
}
private NodePrinter document() {
if (compactMode) {
return (out, node) -> join(out, node.getDefinitions(), " ");
}
return (out, node) -> {
join(out, node.getDefinitions(), "\n\n");
out.append('\n');
};
}
private NodePrinter directive() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
out.append('@');
out.append(node.getName());
if (!isEmpty(node.getArguments())) {
out.append('(');
join(out, node.getArguments(), argSep);
out.append(')');
}
};
}
private NodePrinter directiveDefinition() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
description(out, node);
out.append("directive @");
out.append(node.getName());
if (!isEmpty(node.getInputValueDefinitions())) {
out.append('(');
join(out, node.getInputValueDefinitions(), argSep);
out.append(')');
}
out.append(" ");
if (node.isRepeatable()) {
out.append("repeatable ");
}
out.append("on ");
join(out, node.getDirectiveLocations(), " | ");
};
}
private NodePrinter directiveLocation() {
return (out, node) -> out.append(node.getName());
}
private NodePrinter enumTypeDefinition() {
return (out, node) -> {
description(out, node);
out.append("enum ");
out.append(node.getName());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
out.append(' ');
block(out, node.getEnumValueDefinitions());
};
}
private NodePrinter enumValue() {
return (out, node) -> out.append(node.getName());
}
private NodePrinter enumValueDefinition() {
return (out, node) -> {
description(out, node);
out.append(node.getName());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
};
}
private NodePrinter field() {
final String argSep = compactMode ? "," : ", ";
final String aliasSuffix = compactMode ? ":" : ": ";
return (out, node) -> {
String name = node.getName();
if (!isEmpty(node.getAlias())) {
out.append(node.getAlias());
out.append(aliasSuffix);
}
out.append(name);
if (!isEmpty(node.getArguments())) {
out.append('(');
join(out, node.getArguments(), argSep);
out.append(')');
}
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
if (node.getSelectionSet() != null && !isEmpty(node.getSelectionSet().getSelections())) {
if (!compactMode) {
out.append(' ');
}
node(out, node.getSelectionSet());
}
};
}
private NodePrinter fieldDefinition() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
if (hasDescription(node) && !compactMode) {
description(out, node);
out.append(node.getName());
if (!isEmpty(node.getInputValueDefinitions())) {
out.append("(\n");
join(out, node.getInputValueDefinitions(), "\n");
out.append(')');
}
out.append(": ");
type(out, node.getType());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
} else {
out.append(node.getName());
if (!isEmpty(node.getInputValueDefinitions())) {
out.append('(');
join(out, node.getInputValueDefinitions(), argSep);
out.append(')');
}
out.append(": ");
type(out, node.getType());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
}
};
}
private static boolean hasDescription(Node node) {
if (node instanceof AbstractDescribedNode) {
AbstractDescribedNode describedNode = (AbstractDescribedNode) node;
return describedNode.getDescription() != null;
}
return false;
}
private NodePrinter fragmentDefinition() {
return (out, node) -> {
out.append("fragment ");
out.append(node.getName());
out.append(" on ");
type(out, node.getTypeCondition());
out.append(' ');
directives(out, node.getDirectives());
node(out, node.getSelectionSet());
};
}
private NodePrinter fragmentSpread() {
return (out, node) -> {
out.append("...");
out.append(node.getName());
directives(out, node.getDirectives());
};
}
private NodePrinter inlineFragment() {
return (out, node) -> {
out.append("...");
if (compactMode) {
// believe it or not but "...on Foo" is valid syntax
if (node.getTypeCondition() != null) {
out.append("on ");
type(out, node.getTypeCondition());
}
directives(out, node.getDirectives());
node(out, node.getSelectionSet());
} else {
if (node.getTypeCondition() != null) {
out.append(" on ");
type(out, node.getTypeCondition());
}
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
out.append(' ');
node(out, node.getSelectionSet());
}
};
}
private NodePrinter inputObjectTypeDefinition() {
return (out, node) -> {
description(out, node);
out.append("input ");
out.append(node.getName());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
if (!isEmpty(node.getInputValueDefinitions())) {
out.append(' ');
block(out, node.getInputValueDefinitions());
}
};
}
private NodePrinter inputValueDefinition() {
String nameTypeSep = compactMode ? ":" : ": ";
String defaultValueEquals = compactMode ? "=" : "= ";
return (out, node) -> {
Value defaultValue = node.getDefaultValue();
description(out, node);
out.append(node.getName());
out.append(nameTypeSep);
type(out, node.getType());
if (defaultValue != null) {
out.append(' ');
out.append(defaultValueEquals);
node(out, defaultValue);
}
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
};
}
private NodePrinter interfaceTypeDefinition() {
return (out, node) -> {
description(out, node);
out.append("interface ");
out.append(node.getName());
if (!isEmpty(node.getImplements())) {
out.append(" implements ");
join(out, node.getImplements(), " & ");
}
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
if (!isEmpty(node.getFieldDefinitions())) {
out.append(' ');
block(out, node.getFieldDefinitions());
}
};
}
private NodePrinter objectField() {
String nameValueSep = compactMode ? ":" : " : ";
return (out, node) -> {
out.append(node.getName());
out.append(nameValueSep);
value(out, node.getValue());
};
}
private NodePrinter operationDefinition() {
final String argSep = compactMode ? "," : ", ";
return (out, node) -> {
String name = node.getName();
// Anonymous queries with no directives or variable definitions can use
// the query short form.
if (isEmpty(name) && isEmpty(node.getDirectives()) && isEmpty(node.getVariableDefinitions())
&& node.getOperation() == OperationDefinition.Operation.QUERY) {
node(out, node.getSelectionSet());
} else {
out.append(node.getOperation().toString().toLowerCase());
if (!isEmpty(name)) {
out.append(' ');
out.append(name);
}
if (!isEmpty(node.getVariableDefinitions())) {
if (isEmpty(name)) {
out.append(' ');
}
out.append('(');
join(out, node.getVariableDefinitions(), argSep);
out.append(')');
}
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
if (!compactMode) {
out.append(' ');
}
node(out, node.getSelectionSet());
}
};
}
private NodePrinter operationTypeDefinition() {
String nameTypeSep = compactMode ? ":" : ": ";
return (out, node) -> {
out.append(node.getName());
out.append(nameTypeSep);
type(out, node.getTypeName());
};
}
private NodePrinter objectTypeDefinition() {
return (out, node) -> {
description(out, node);
out.append("type ");
out.append(node.getName());
if (!isEmpty(node.getImplements())) {
out.append(" implements ");
join(out, node.getImplements(), " & ");
}
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
if (!isEmpty(node.getFieldDefinitions())) {
out.append(' ');
block(out, node.getFieldDefinitions());
}
};
}
private NodePrinter selectionSet() {
return (out, node) -> block(out, node.getSelections());
}
private NodePrinter scalarTypeDefinition() {
return (out, node) -> {
description(out, node);
out.append("scalar ");
out.append(node.getName());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
};
}
private NodePrinter schemaDefinition() {
return (out, node) -> {
description(out, node);
out.append("schema ");
if (!isEmpty(node.getDirectives())) {
directives(out, node.getDirectives());
out.append(' ');
}
block(out, node.getOperationTypeDefinitions());
};
}
private NodePrinter> type() {
return this::type;
}
private void type(StringBuilder out, Type type) {
if (type instanceof NonNullType) {
NonNullType inner = (NonNullType) type;
type(out, inner.getType());
out.append('!');
} else if (type instanceof ListType) {
ListType inner = (ListType) type;
out.append('[');
type(out, inner.getType());
out.append(']');
} else {
TypeName inner = (TypeName) type;
out.append(inner.getName());
}
}
private NodePrinter objectTypeExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, ObjectTypeDefinition.class);
};
}
private NodePrinter enumTypeExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, EnumTypeDefinition.class);
};
}
private NodePrinter interfaceTypeExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, InterfaceTypeDefinition.class);
};
}
private NodePrinter unionTypeExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, UnionTypeDefinition.class);
};
}
private NodePrinter scalarTypeExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, ScalarTypeDefinition.class);
};
}
private NodePrinter inputObjectTypeExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, InputObjectTypeDefinition.class);
};
}
private NodePrinter schemaExtensionDefinition() {
return (out, node) -> {
out.append("extend ");
node(out, node, SchemaDefinition.class);
};
}
private NodePrinter unionTypeDefinition() {
String barSep = compactMode ? "|" : " | ";
String equals = compactMode ? "=" : "= ";
return (out, node) -> {
description(out, node);
out.append("union ");
out.append(node.getName());
if (!isEmpty(node.getDirectives())) {
out.append(' ');
directives(out, node.getDirectives());
}
out.append(' ');
out.append(equals);
join(out, node.getMemberTypes(), barSep);
};
}
private NodePrinter variableDefinition() {
String nameTypeSep = compactMode ? ":" : ": ";
String defaultValueEquals = compactMode ? "=" : " = ";
return (out, node) -> {
out.append('$');
out.append(node.getName());
out.append(nameTypeSep);
type(out, node.getType());
if (node.getDefaultValue() != null) {
out.append(defaultValueEquals);
node(out, node.getDefaultValue());
}
directives(out, node.getDirectives());
};
}
private NodePrinter variableReference() {
return (out, node) -> out.append('$').append(node.getName());
}
private String node(Node node) {
return node(node, null);
}
private void node(StringBuilder out, Node node) {
node(out, node, null);
}
private String node(Node node, Class startClass) {
StringBuilder builder = new StringBuilder();
node(builder, node, startClass);
return builder.toString();
}
private void node(StringBuilder out, Node node, Class startClass) {
if (startClass != null) {
assertTrue(startClass.isInstance(node), () -> "The starting class must be in the inherit tree");
}
NodePrinter> printer = _findPrinter(node, startClass);
printer.print(out, node);
}
@SuppressWarnings("unchecked")
NodePrinter _findPrinter(Node node) {
return _findPrinter(node, null);
}
NodePrinter _findPrinter(Node node, Class startClass) {
if (node == null) {
return (out, type) -> {
};
}
Class clazz = startClass != null ? startClass : node.getClass();
while (clazz != Object.class) {
NodePrinter nodePrinter = printers.get(clazz);
if (nodePrinter != null) {
//noinspection unchecked
return nodePrinter;
}
clazz = clazz.getSuperclass();
}
return assertShouldNeverHappen("We have a missing printer implementation for %s : report a bug!", clazz);
}
private static boolean isEmpty(List list) {
return list == null || list.isEmpty();
}
private static boolean isEmpty(String s) {
return s == null || s.isBlank();
}
private static List nvl(List list) {
return list != null ? list : ImmutableKit.emptyList();
}
private NodePrinter> value() {
return this::value;
}
private void value(StringBuilder out, Value value) {
String argSep = compactMode ? "," : ", ";
if (value instanceof IntValue) {
out.append(((IntValue) value).getValue());
} else if (value instanceof FloatValue) {
out.append(((FloatValue) value).getValue());
} else if (value instanceof StringValue) {
out.append('"');
escapeJsonStringTo(out, ((StringValue) value).getValue());
out.append('"');
} else if (value instanceof EnumValue) {
out.append(((EnumValue) value).getName());
} else if (value instanceof BooleanValue) {
out.append(((BooleanValue) value).isValue());
} else if (value instanceof NullValue) {
out.append("null");
} else if (value instanceof ArrayValue) {
out.append('[');
join(out, ((ArrayValue) value).getValues(), argSep);
out.append(']');
} else if (value instanceof ObjectValue) {
out.append('{');
join(out, ((ObjectValue) value).getObjectFields(), argSep);
out.append('}');
} else if (value instanceof VariableReference) {
out.append('$');
out.append(((VariableReference) value).getName());
}
}
private void description(StringBuilder out, Node node) {
Description description = ((AbstractDescribedNode) node).getDescription();
if (description == null || description.getContent() == null || compactMode) {
return;
}
;
if (description.isMultiLine()) {
out.append("\"\"\"");
if (description.getContent().isEmpty() || description.getContent().charAt(0) != '\n') {
out.append('\n');
}
out.append(description.getContent());
out.append("\n\"\"\"\n");
} else {
out.append('"');
escapeJsonStringTo(out, description.getContent());
out.append("\"\n");
}
}
private void directives(StringBuilder out, List directives) {
join(out, nvl(directives), compactMode ? "" : " ");
}
private > void join(StringBuilder out, List nodes, String delim) {
if (isEmpty(nodes)) {
return;
}
Iterator iterator = nodes.iterator();
node(out, iterator.next());
while (iterator.hasNext()) {
out.append(delim);
node(out, iterator.next());
}
}
/*
* Some joined nodes don't need delimiters between them and some do
* This encodes that knowledge of those that don't require delimiters
*/
@SuppressWarnings("SameParameterValue")
private > void joinTight(StringBuilder output, List nodes, String delim, String prefix, String suffix) {
output.append(prefix);
boolean first = true;
for (T node : nodes) {
if (first) {
first = false;
} else {
if (output.charAt(output.length() - 1) != '}') {
output.append(delim);
}
}
node(output, node);
}
output.append(suffix);
}
String wrap(String start, String maybeString, String end) {
if (isEmpty(maybeString)) {
if (start.equals("\"") && end.equals("\"")) {
return "\"\"";
}
return "";
}
return start + maybeString + (!isEmpty(end) ? end : "");
}
private > void block(StringBuilder out, List nodes) {
if (isEmpty(nodes)) {
return;
}
if (compactMode) {
out.append('{');
joinTight(out, nodes, " ", "", "");
out.append('}');
} else {
int offset = out.length();
out.append("{\n");
join(out, nodes, "\n");
indent(out, offset);
out.append("\n}");
}
}
private static void indent(StringBuilder maybeString, int offset) {
for (int i = offset; i < maybeString.length(); i++) {
char c = maybeString.charAt(i);
if (c == '\n') {
maybeString.replace(i, i + 1, "\n ");
i += 3;
}
}
}
@SuppressWarnings("SameParameterValue")
String wrap(String start, Node maybeNode, String end) {
if (maybeNode == null) {
return "";
}
return start + node(maybeNode) + (isEmpty(end) ? "" : end);
}
/**
* This will pretty print the AST node in graphql language format
*
* @param node the AST node to print
*
* @return the printed node in graphql language format
*/
public static String printAst(Node node) {
StringBuilder builder = new StringBuilder();
printImpl(builder, node, false);
return builder.toString();
}
/**
* This will pretty print the AST node in graphql language format
*
* @param writer the place to put the output
* @param node the AST node to print
*/
public static void printAst(Writer writer, Node node) {
String ast = printAst(node);
PrintWriter printer = new PrintWriter(writer);
printer.write(ast);
}
/**
* This will print the Ast node in graphql language format in a compact manner, with no new lines
* and descriptions stripped out of the text.
*
* @param node the AST node to print
*
* @return the printed node in a compact graphql language format
*/
public static String printAstCompact(Node node) {
StringBuilder builder = new StringBuilder();
printImpl(builder, node, true);
return builder.toString();
}
private static void printImpl(StringBuilder writer, Node node, boolean compactMode) {
AstPrinter astPrinter = new AstPrinter(compactMode);
NodePrinter printer = astPrinter._findPrinter(node);
printer.print(writer, node);
}
/**
* These print nodes into output writers
*
* @param the type of node
*/
interface NodePrinter {
void print(StringBuilder out, T node);
}
/**
* Allow subclasses to replace a printer for a specific {@link Node}
*
* @param nodeClass the class of the {@link Node}
* @param nodePrinter the custom {@link NodePrinter}
*/
void replacePrinter(Class nodeClass, NodePrinter nodePrinter) {
this.printers.put(nodeClass, nodePrinter);
}
}
© 2015 - 2025 Weber Informatics LLC | Privacy Policy