反应中继错误'对象没有方法找到'答案

【问题标题】：React Relay Error 'Object has no method find'反应中继错误'对象没有方法找到'
【发布时间】：2016-06-28 13:24:32
【问题描述】：

我一直在使用 reactjs，并认为我会开始使用 graphql 和 relay。我遇到了一个我无法深入了解的错误，所以我想知道这里是否有人遇到过同样的错误。欢迎任何指点或想法。

我得到的错误是

Error: GraphQL validation/transform error ``Object  has no method 'find'`` in file `/Users/chris/Documents/App/site/js/main.js`.

所以我有一个 GraphQL 服务器正在运行，一切正常我可以查询后端数据库（我正在使用 mongodb），以下查询通过 graphql ui 产生正确的结果

{
  store{
    items{
        _id
        title
        sub
    }
  }
}

produces the following output which is correct

{
  "data": {
    "store": {
      "items": [
        {
          "_id": "56e2c71d150040c491c73b26",
          "title": "Test Item One",
          "sub": "sub title here"
        }
      ]
    }
  }
}

所以我认为可以安全地假设 graphql 服务器很好，问题一定是我的中继实现或 babelRelayPlugin.js

以下是简化渲染方法的main.js文件。

import React from 'react';
import Relay from 'react-relay';


class Main extends React.Component {

    render(){
        return (
            <div>
                <p>Test</p>
            </div>
        );
    }
}

Main = Relay.createContainer(Main, {
    fragments:{
        store: () => Relay.QL`
            fragment on Store {
                items {
                    title,
                }
              }
           `
    }
});

export default Main;

以下是App.js文件

import React from 'react';
import ReactDOM from 'react-dom';
import Relay from 'react-relay';
import Main from './main'

//React.render(<Main />, document.getElementById('react-main-mount'));

class HomeRoute extends Relay.Route {
    static routeName = 'Home';
    static queries = {
        store:(Component) => Relay.QL`
        query MainQuery {
            store { ${Component.getFragment('store')}}
        }`
    }
};

ReactDOM.render(<Relay.RootContainer 
                    Component={Main} 
                    route={new HomeRoute()} 
                />, 
                document.getElementById('react-main-mount')
               );

为了完整起见，这里是我正在使用的 schema.js。

import { GraphQLSchema, 
         GraphQLObjectType,
         GraphQLList,
         GraphQLInt,
         GraphQLString
       } from 'graphql';

// Schema allows us to use node feature to link the schema to the database
let Schema = (db) => {
let store = {};

let storeType = new GraphQLObjectType({
    name:'Store',
    fields:() => ({
        items: {
            type: new GraphQLList(itemType),
            resolve:() => db.collection("Item").find({}).toArray()
        }
    })
});

let itemType = new GraphQLObjectType({
    name: 'Item',
    fields:() =>({
        _id:{type: GraphQLString},
        title: {type: GraphQLString},
        sub:{type:GraphQLString},
        type:{type:GraphQLString},
        comments:{type:GraphQLInt}
    })
});

let schema = new GraphQLSchema({
    query: new GraphQLObjectType({
        name:'Query',
        fields: () => ({
            store: {
                type: storeType,
                resolve: () => store
            }

        })
    }),
});
    return schema;
};
export default Schema;

此处显示的服务器将其转换为 JSON

let app = express();
app.use(express.static('site')); // public folder

console.log("Starting Server");
//mongo url is the server 
(async () => {
    try{
    let db = await MongoClient.connect("mongodb://localhost:27017/App");
    let schema = Schema(db); 

    app.use('/graphql', GraphQLHTTP({
        schema,
        graphiql:true
    }));

  app.listen(3000, () => console.log('listening on port 3000'));  

  // Generate Schema
  let json = await graphql(schema, introspectionQuery); 
  fs.writeFile('./database/schema.json', JSON.stringify(json,null,2), err => {
      if(err) throw err;
      console.log("JSON schema created");
  });
    }catch(e){
        console.log(e);
    }
})();

下面是babelRelayPlugin.js

var getBabelRelayPlugin = require('babel-relay-plugin');
var schemaData = require('./database/schema.json').data;
module.exports = getBabelRelayPlugin(schemaData);

还有 Webpack.config

module.exports = {
    entry:'./site/js/app.js',
    output:{
        path: __dirname + "/site",
        filename: "bundle.js"
    },
    module:{
        loaders:[
            {test:/\.js$/, exclude:/node_modules/, loader: 'babel-loader',
             query: {presets: ['react', 'es2015', 'stage-0'],
                     plugins: ['./babelRelayPlugin']
                    }
            }
        ]
    }
}

更新： 所以我玩了一下，问题出在 main.js RelayQL 语句

Main = Relay.createContainer(Main, {
        fragments:{
            store: () => Relay.QL`
                fragment on Store {
                    items {
                        title,
                    }
                  }
               `
        }
    });

我注释掉了 app.js 中的代码，并将其替换为以下代码作为测试，以查看基本的基本中继查询是否有效，并且通过将正确的输出返回到控制台来实现

ReactDOM.render(<Main />, document.getElementById('react-main-mount'));
console.log(Relay.QL`query store { store{ items {title}}}`);

所以正如我上面提到的，问题一定是我怀疑 main.js 中的真正声明，现在问题是为什么？

为了完整起见，我在下面包含了完整的错误堆栈跟踪

-- Relay Transform Error -- main --

File:  /Users/chris/Documents/App/site/js/main.js
Error: TypeError: Object  has no method 'find'
    at new RelayQLFragment (/Users/chris/Documents/App/node_modules/babel-relay-plugin/lib/RelayQLAST.js:143:49)
    at RelayQLTransformer.processDocumentText (/Users/chris/Documents/App/node_modules/babel-relay-plugin/lib/RelayQLTransformer.js:156:16)
    at RelayQLTransformer.transform (/Users/chris/Documents/App/node_modules/babel-relay-plugin/lib/RelayQLTransformer.js:67:29)
    at PluginPass.TaggedTemplateExpression (/Users/chris/Documents/App/node_modules/babel-relay-plugin/lib/getBabelRelayPlugin.js:124:36)
    at newFn (/Users/chris/Documents/App/node_modules/babel-traverse/lib/visitors.js:262:19)
    at NodePath._call (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:63:18)
    at NodePath.call (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:47:17)
    at NodePath.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:93:12)
    at TraversalContext.visitQueue (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:146:16)
    at TraversalContext.visitSingle (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:115:19)
    at TraversalContext.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:178:19)
    at Function.traverse.node (/Users/chris/Documents/App/node_modules/babel-traverse/lib/index.js:135:17)
    at NodePath.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:103:22)
    at TraversalContext.visitQueue (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:146:16)
    at TraversalContext.visitMultiple (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:110:17)
    at TraversalContext.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:176:19)
    at Function.traverse.node (/Users/chris/Documents/App/node_modules/babel-traverse/lib/index.js:135:17)
    at NodePath.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:103:22)
    at TraversalContext.visitQueue (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:146:16)
    at TraversalContext.visitSingle (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:115:19)
    at TraversalContext.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:178:19)
    at Function.traverse.node (/Users/chris/Documents/App/node_modules/babel-traverse/lib/index.js:135:17)
    at NodePath.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:103:22)
    at TraversalContext.visitQueue (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:146:16)
    at TraversalContext.visitSingle (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:115:19)
    at TraversalContext.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:178:19)
    at Function.traverse.node (/Users/chris/Documents/App/node_modules/babel-traverse/lib/index.js:135:17)
    at NodePath.visit (/Users/chris/Documents/App/node_modules/babel-traverse/lib/path/context.js:103:22)
    at TraversalContext.visitQueue (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:146:16)
    at TraversalContext.visitMultiple (/Users/chris/Documents/App/node_modules/babel-traverse/lib/context.js:110:17)

【问题讨论】：

标签： reactjs graphql relayjs

【解决方案1】：

在您的 HomeRoute 中：

class HomeRoute extends Relay.Route {
    static routeName = 'Home';
    static queries = {
        store:(Component) => Relay.QL`
        query MainQuery {
            store { ${Component.getFragment('store')}}
        }`
    }
};

你试过了吗：

    static queries = {
        store:() => Relay.QL`
        query MainQuery {
            store
        }`
    }

【讨论】：

简化 HomeRoute 的好主意，（诚然我没有尝试过）但不幸的是我仍然遇到同样的问题，我认为语法是正确的，我认为问题可能与连接设置有关本身作为运行'webpack -wd'会产生错误
错误似乎指向商店 -> 字段 -> 项目 -> resolve:() => db.collection("Item").find({}).toArray() 的 GraphQL 架构。也许不是使用 .find()，而是尝试返回一个固定的项目数组，看看问题是否消失。
不幸的是，没有同样的问题。 GraphQL 服务器工作令人费解，生成的 JSON 看起来正确，我可能需要在重新安装一些模块后再次重新实现中继端。 - 为建议干杯
我看到了你刚刚在console.log(Relay.QL`query store { store{ items {title}}}`); 处所做的更新，它奏效了！但是，执行此查询类似于您的 HomeRoute 执行它，而不是您的 Main Relay 片段代码执行它，这就是您要比较的。尝试使用您在 console.log 中使用的相同的 Relay.QL 更新 HomeRoute。
或者，您可以尝试将现有的 HomeRoute 查询填充到 console.log 中：console.log(Relay.QL`query MainQuery { store { ${Component.getFragment('store') } } }`)。这行得通吗？