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    graphql-lodash
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    1.3.4 • Public • Published

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    GraphQL Lodash

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    Unleash the power of lodash inside your GraphQL queries

    Table of contents

    Why?

    GraphQL allows to ask for what you need and get exactly that. But what about the shape? GraphQL Lodash gives you the power of lodash right inside your GraphQL Query using @_ directive.

    lodash usage gif

    Note: This is an experimental project created to explore the concept of Query and transformation collocation.

    We encourage you to try it inside our demo or check detailed walkthrough.

    Example queries

    Here are a few query examples you can run against StartWars API:

    Find the planet with the biggest population

    Find the planet with the biggest population

    Get gender statistics

    Get gender statistics

    Map characters to films they are featured in

    Map characters to films they are featured in

    Install

    npm install --save graphql-lodash
    

    or

    yarn add graphql-lodash
    

    API

    graphqlLodash(query, [operationName])

    • query (required) - query string or query AST
    • operationName (optional) - required only if the query contains multiple operations

    Returns

    {
      query: string|object,
      transform: Function
    }
    
    • query - the original query with stripped @_ directives
    • transform - function that recieves response.data as a single argument and returns the same data in the intended shape.

    Usage Examples

    The simplest way to integrate graphql-lodash is to write wrapper function for graphql client of you choice:

    import { graphqlLodash } from 'graphql-lodash';
     
    function lodashQuery(queryWithLodash) {
      let { query, transform } = graphqlLodash(queryWithLodash);
      // Make a GraphQL call using 'query' variable as a query
      // And place result in 'result' variable
      ...
      result.data = transform(result.data);
      return result;
    }

    Fetch example

    An example of a simple client based on fetch API:

    function executeGraphQLQuery(url, query) {
      return fetch(url, {
        method: 'POST',
        headers: new Headers({"content-type": 'application/json'}),
        body: JSON.stringify({ query: query })
      }).then(response => {
        if (response.ok)
          return response.json();
        return response.text().then(body => {
          throw Error(response.status + ' ' + response.statusText + '\n' + body);
        });
      });
    }
     
    function lodashQuery(url, queryWithLodash) {
      let { query, transform } = window.GQLLodash.graphqlLodash(queryWithLodash);
      return executeGraphQLQuery(url, query).then(result => {
        result.data = transform(result.data);
        return result;
      });
    }
     
    // then use as bellow
    lodashQuery('https://swapi.apis.guru', `{
      planetWithMaxPopulation: allPlanets @_(get: "planets") {
        planets @_(maxBy: "population") {
          name
          population
        }
      }
    }`).then(result => console.log(result.data));

    Caching clients

    For caching clients like Relay and Apollo we recommend to apply the transformation after the caching layer. Here is proposed solution for Relay:

    Relay usage

    We are still figuring out how to do this and any feedback is welcome.

    Usage with react-apollo

    When using with Apollo you can use props option to apply transformations:

    const rawQuery = gql`
      # query with @_ directives
    `;
     
    const {query, transform} = graphqlLodash(rawQuery);
    export default graphql(query, {
      props: (props) => ({...props, rawData: props.data, data: transform(props.data)})
    })(Component);

    You can write a simple wrapper for simplicity:

    import { graphql } from 'react-apollo';
    import { graphqlLodash } from 'graphql-lodash';
     
    export function gqlLodash(rawQuery, config) {
      const {query, transform} = graphqlLodash(rawQuery);
      let origProps = (config && config.props) || ((props) => props);
     
      return (comp) => graphql(query, {...config,
        props: (props) => origProps({
          ...props,
          rawData: props.data,
          data: transform(props.data)
        })
      })(comp);
    }
    // then use as bellow
    export default gqlLodash(query)(Component);

    Just replace graphql with gqlLodash and you are ready to use lodash in your queries. Check out the react-apollo-lodash-demo repo.

    You can also do the transformation inside an Apollo Link by rewriting the parsed GraphQL Document:

    new ApolloLink((operation, forward) => {
      const { query, transform } = graphqlLodash(operation.query);
      operation.query = query;
      return forward(operation)
        .map(response => ({
          ...response,
          data: transform(response.data),
        }));
    });

    Chaining this link with the other links passed to your ApolloClient will apply the transformation to every query that Apollo runs, such as those from the <Query /> component or subscriptions.

    Introspection queries

    If your application uses introspection queries (like GraphiQL does to get documentation and autocomplete information), you will also need to extend the introspection query result with the directives from graphql-lodash. One way you could do this is:

    import {
      buildClientSchema,
      extendSchema,
      graphqlSync,
      introspectionQuery,
    } from 'graphql';
     
    // inside the above ApolloLink function
    if (response.data && response.data.__schema) {
      const schema = extendSchema(
        buildClientSchema(response.data),
        lodashDirectiveAST,
      );
      return graphqlSync(schema, introspectionQuery);
    }

    See the demo/ source in this repo for another example of modifying the introspection query result.

    Usage on server side

    In theory, this tool can be used on the server. But this will break the contract and, most likely, will break all the GraphQL tooling you use. Use it on server-side only if you know what you do.

    Install

    npm i graphql-lodash

    DownloadsWeekly Downloads

    609

    Version

    1.3.4

    License

    MIT

    Unpacked Size

    1.38 MB

    Total Files

    14

    Last publish

    Collaborators

    • i1g
    • romanhotsiy