如何在不丢失 "this" 上下文的情况下从 React 组件写入 apollo 缓存

Question

我在尝试从 react 组件中读取 apollo 缓存时遇到问题，突变起作用并写入我的服务器和 returns 数据但是当传递到我的更新函数时似乎在 inMemoryCache.js

中失去上下文

"apollo-cache-inmemory": "^1.2.5"
"react-apollo": "^2.1.4"
"apollo-boost": "^0.1.7"

TypeError: Cannot read property 'read' of undefined at ./node_modules/apollo-cache-inmemory/lib/inMemoryCache.js.InMemoryCache.readQuery

import React, { Component } from "react";
import { graphql } from "react-apollo";
import trim from "lodash/trim";

import AuthorForm from '../components/author-form';

import ALL_AUTHORS from "../graphql/getPosts.query";
import CREATE_AUTHOR from "../graphql/createAuthor.mutation";

class CreateAuthor extends Component {
  state = {
    errors: false
  };

  onSubmit(event) {
    event.preventDefault();

    const form = new FormData(event.target);

    const data = {
      firstName: form.get("firstName"),
      lastName: form.get("lastName")
    };

    if (!data.firstName || !data.lastName) {
      return this.setState({ errors: true });
    }

    this.create({
      firstName: trim(data.firstName),
      lastName: trim(data.lastName)
    });
  }

  async create(variables) {
    const { createAuthor } = this.props;
    this.setState({ errors: false });

    try {
      await createAuthor({
        variables,
        update: (cache, data) => this.updateCache(cache, data)
      })
    } catch (e) {
      this.setState({ errors: true })
    }
  }

  updateCache({ readQuery, writeQuery }, { data: { createAuthor }, errors }) {
    if (errors) {
      return;
    }
    const { allAuthors } = readQuery({
      query: ALL_AUTHORS,
      defaults: {
        allAuthors: []
      }
    });
    /*eslint-disable*/ console.log(allAuthors);
  }

  render() {
    return (
      <div>
        <AuthorForm onSubmit={this.onSubmit.bind(this)}/>
        <OnError/>
      </div>
    );
  }
}

export default graphql(CREATE_AUTHOR, { name: "createAuthor" })(CreateAuthor);

跟我绑定onSubmit按钮有关系吗？如果是这样，在不丢失组件内 this 上下文的情况下将函数附加到元素的正确方法是什么，并且仍然允许 apollo 缓存正常运行。

Answer 1

我失去了这方面的背景，因为我正在解构第一个论点。这是我最后确定的。

当 ROOT_QUERY 对象上没有 allAuthors 时会抛出错误，因此将其添加到我的 return 语句中。

这不是更新缓存的理想方式，不应将默认参数传递给 readQuery 以防止引发错误。

 updateCache(cache, { data: { createAuthor }, errors }) {
    if (errors || !cache.data.data.ROOT_QUERY.allAuthors) {
      return;
    }

    const query = ALL_AUTHORS;

    const { allAuthors } = cache.readQuery({
      query,
      defaults: {
        allAuthors: []
      }
    });

    const data = {
      allAuthors: allAuthors.concat([createAuthor])
    };

    cache.writeQuery({
      query,
      data
    });
  }

如何在不丢失 "this" 上下文的情况下从 React 组件写入 apollo 缓存

How to write to apollo cache from within React component with out losing context of "this"

javascript

apollo

reactjs

graphql

apollo-client