50 lines
1.1 KiB
Dart
50 lines
1.1 KiB
Dart
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import 'package:graphql_parser/graphql_parser.dart';
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import 'package:graphql_parser/visitor.dart';
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const String QUERY = '''
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{
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foo,
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baz: bar
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}
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''';
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const Map<String, dynamic> DATA = const {
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'foo': 'hello',
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'bar': 'world',
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'quux': 'extraneous'
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};
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main() {
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// Highly-simplified querying example...
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var result = new MapQuerier(DATA).execute(QUERY);
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print(result); // { foo: hello, baz: world }
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print(result['foo']); // hello
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print(result['baz']); // world
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}
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class MapQuerier extends GraphQLVisitor {
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final Map<String, dynamic> data;
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final Map<String, dynamic> result = {};
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MapQuerier(this.data);
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Map<String, dynamic> execute(String query) {
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var doc = new Parser(scan(query)).parseDocument();
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visitDocument(doc);
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return result;
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}
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@override
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visitField(FieldContext ctx) {
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String realName, alias;
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if (ctx.fieldName.alias == null)
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realName = alias = ctx.fieldName.name;
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else {
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realName = ctx.fieldName.alias.name;
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alias = ctx.fieldName.alias.alias;
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}
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// Set output field...
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result[alias] = data[realName];
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}
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}
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