CDK Appsync Mapping Templates

CDK Appsync resolver mapping templates with the full range of options available.

Why?

The CDK Appsync module comes with the built in MappingTemplate class, but it's very opinionated. For example if you want to use MappingTemplate.dynamoDbQuery you can't specify the query expression as from $ctx.source, so you can't create nested field resolvers with it. Similarly you can't have pagination as the limit/nextToken parameters are unavailable.

This module lets you instead specify everything directly using exactly the format of the AWS Appsync resolver mapping template docs, with the benefit of TypeScript typings and suggestions.

Install

You must also install AWS cdk appsync as a peer dependency.

yarn install @aws-cdk/aws-appsync cdk-appsync-mapping-templates

Example Use

import MappingTemplate, {
  DynamoDBSelect,
  DynamoDBOperation,
} from 'cdk-appsync-mapping-templates';
import { Resolver } from '@aws-cdk/aws-appsync';

const requestMappingTemplate = MappingTemplate.dynamoDB({
  version: '2017-02-28',
  operation: DynamoDBOperation.QUERY,
  query: {
    expression: 'some expression',
    expressionNames: {
      '#foo': 'foo',
    },
    expressionValues: {
      ':bar': '$util.dynamodb.toDynamoDBJson($ctx.source.id)',
    },
  },
  index: 'fooIndex',
  nextToken: '$ctx.args.nextToken',
  limit: '$ctx.args.limit',
  scanIndexForward: true,
  consistentRead: false,
  select: DynamoDBSelect.ALL_ATTRIBUTES,
  filter: {
    //...
  },
});

new Resolver(this, 'dynamoDBQueryResolver', {
  //...
  requestMappingTemplate,
});

Built by Skyhook

This module is contributed by the team at Skyhook.