Введение

Response Schema (same as axios, typed with AxiosResponse if using TypeScript)

The response for a request contains the following information.


{
  // `data` is the response that was provided by the server
  data: {},

  // `status` is the HTTP status code from the server response
  status: 200,

  // `statusText` is the HTTP status message from the server response
  statusText: 'OK',

  // `headers` the headers that the server responded with
  // All header names are lower cased
  headers: {},

  // `config` is the config that was provided to `axios` for the request
  config: {},

  // `request` is the request that generated this response
  // It is the last ClientRequest instance in node.js (in redirects)
  // and an XMLHttpRequest instance the browser
  request: {}
}

Example

Performing a request

import Axios from  'axios-observable';
// or const Axios = require('axios-observable').Axios;

// Make a request for a user with a given ID
Axios.get('/user?ID=12345')
  .subscribe(
    response => console.log(response),
    error => console.log(error)
  );

// Optionally the request above could also be done as
Axios.get('/user?ID=12345'), {
    params: {
      ID: 12345
    }
  })
  .subscribe(
    response => console.log(response),
    error => console.log(error)
  );

Performing a request

Axios.post('/user', {
    firstName: 'Fred',
    lastName: 'Flintstone'
  })
   .subscribe(
    response => console.log(response),
    error => console.log(error)
  );

Request Config

These are the available config options for making requests. Only the is required. Requests will default to if is not specified.

{  url'/user',  method'get',  baseURL'https://some-domain.com/api/',  transformRequestfunction(data,headers){return data;},  transformResponsefunction(data){return data;},  headers{'X-Requested-With''XMLHttpRequest'},  params{ID12345},paramsSerializerfunction(params){returnQs.stringify(params,{arrayFormat'brackets'})},  data{    firstName'Fred'},  timeout1000,  withCredentialsfalse,adapterfunction(config){},  auth{    username'janedoe',    password's00pers3cret'},  responseType'json',  xsrfCookieName'XSRF-TOKEN',  xsrfHeaderName'X-XSRF-TOKEN',onUploadProgressfunction(progressEvent){},onDownloadProgressfunction(progressEvent){},  maxContentLength2000,validateStatusfunction(status){return status >=200&& status <300;},  maxRedirects5,  httpAgentnewhttp.Agent({ keepAlivetrue}),  httpsAgentnewhttps.Agent({ keepAlivetrue}),  proxy{    host'127.0.0.1',    port9000,    auth{      username'mikeymike',      password'rapunz3l'}},  cancelTokennewCancelToken(function(cancel){})}

Interceptors

You can intercept requests or responses before they are handled by or .

axios.interceptors.request.use(function(config){return config;},function(error){returnPromise.reject(error);});axios.interceptors.response.use(function(response){return response;},function(error){returnPromise.reject(error);});

If you need to remove an interceptor later you can.

constmyInterceptor=axios.interceptors.request.use(function(){});axios.interceptors.request.eject(myInterceptor);

You can add interceptors to a custom instance of axios.

constinstance=axios.create();instance.interceptors.request.use(function(){});

Загрузка нескольких файлов

Обработка нескольких файлов очень похожа на загрузку одиного файла. Мы начнем с шаблона, который будет выглядеть следующим образом в нашем компоненте Vue:

<template>
  <div class="container">
    <div class="large-12 medium-12 small-12 cell">
      <label>Files
        <input type="file" id="files" ref="files" multiple v-on:change="handleFileUploads()"/>
      </label>
      <button v-on:click="submitFiles()">Submit</button>
    </div>
  </div>
</template>

Помимо изменения имени атрибута ref и изменения идентификатора на files, наиболее важным атрибутом является то, что мы добавили multiple к нашему input. Это позволит пользователю использовать cmd (ctrl) + клик, чтобы выбрать несколько файлов одновременно. В следующем разделе мы позволим пользователю удалять файлы и выбирать больше файлов, если они допустили ошибку .

Метод загрузки нескольких файлов handleFileUploads()

Он очень похож на загрузку одного файла, за исключением того, что мы добавим все файлы в наш массив, если пользователь выберет более одного. Во-первых, давайте добавим новое хранилище данных в компонент Vue и присвоим этой переменной имя files:

data(){
  return {
    files: ''
  }
},

Теперь у нас есть локальная переменная для хранения наших файлов. Теперь мы можем сделать наш метод handleFileUploads():

handleFilesUpload(){
  this.files = this.$refs.files.files;
}

Он позволяет получить все файлы из FilesList из нашей загрузки файлов и сохранить их локально.

Реализация метода submitFiles()

Теперь у нас все готово чтобы отправить все наши файлы на сервер! Во-первых, давайте добавим наш метод submitFiles() в массив методов:

submitFiles(){

},

Как и в последнем методе, сначала инициализируем объект FormData():

let formData = new FormData();

Теперь, переберем все выбранные файлы и добавить их в массив files, который мы собираемся отправить на сервер. Массив files будет ключом в объекте formData(), который мы будем отправлять на сервер:

for( var i = 0; i < this.files.length; i++ ){
  let file = this.files;

  formData.append('files', file);
}

Теперь мы готовы отправить наши файлы на сервер через Axios:

axios.post( '/multiple-files',
  formData,
  {
    headers: {
        'Content-Type': 'multipart/form-data'
    }
  }
).then(function(){
  console.log('SUCCESS!!');
})
.catch(function(){
  console.log('FAILURE!!');
});

На стороне сервера вы можете получить доступ к файлам через ключ files, который является первым параметром formData.append(‘files’, file);.

В PHP это может быть: $_FILES, а в Laravel вы можете обращаться к нему через Request::file(‘files’) и выполнять любую обработку на стороне сервера, которая вам нужна. Теперь вы можете просмотреть все файлы, чтобы можно было загружать их несколько раз.


Наш компонент MultipleFiles.vue должен выглядеть следующим образом:

<template>
  <div class="container">
    <div class="large-12 medium-12 small-12 cell">
      <label>Files
        <input type="file" id="files" ref="files" multiple v-on:change="handleFilesUpload()"/>
      </label>
      <button v-on:click="submitFiles()">Submit</button>
    </div>
  </div>
</template>

<script>
  export default {
    /*
      Defines the data used by the component
    */
    data(){
      return {
        files: ''
      }
    },

    methods: {
      submitFiles(){
        let formData = new FormData();

        for( var i = 0; i < this.files.length; i++ ){
          let file = this.files;

          formData.append('files', file);
        }

        axios.post( '/multiple-files',
          formData,
          {
            headers: {
                'Content-Type': 'multipart/form-data'
            }
          }
        ).then(function(){
          console.log('SUCCESS!!');
        })
        .catch(function(){
          console.log('FAILURE!!');
        });
      },

      handleFilesUpload(){
        this.files = this.$refs.files.files;
      }
    }
  }
</script>

Следующим шагом мы позволим пользователям редактировать файлы, которые они выбрали, чтобы они случайно не загрузили файл, который им не нужен.

Interceptors

You can intercept requests or responses before they are handled by or .

// Add a request interceptor
Axios.interceptors.request.use(function (config) {
    // Do something before request is sent
    return config;
  }, function (error) {
    // Do something with request error
    return Promise.reject(error);
  });

// Add a response interceptor
Axios.interceptors.response.use(function (response) {
    // Do something with response data
    return response;
  }, function (error) {
    // Do something with response error
    return Promise.reject(error);
  });

If you may need to remove an interceptor later you can.

const myInterceptor = Axios.interceptors.request.use(function () {/*...*/});
Axios.interceptors.request.eject(myInterceptor);

You can add interceptors to a custom instance of axios.

const instance = Axios.create();
instance.interceptors.request.use(function () {/*...*/});

You can define a custom HTTP status code error range using the config option.

Axios.get('/user/12345', {
  validateStatus: function (status) {
    return status < 500; // Reject only if the status code is greater than or equal to 500
  }
})

Why Do We Need Axios?

Most web and mobile apps store data in the cloud or communicate with a service. For example, a service that gets the current weather in your local area, or returns a list of GIFs based on a search term.

Databases and web services have something called an API (Application Programming Interface) which apps can use to communicate with through a URL. In other words, an API allows apps to retrieve or send data to and from databases or web services.

Apps use HTTP requests, for example, GET, POST and PUT, to communicate with APIs. In short, Axios make it easy for our apps to perform these commands.

To learn more about fetching data from an API in a real application, check out our tutorial on building a complete React app with Airtable.

withAxios(options)(Component) HoC

If you want to create your own component with the full react-axios request . You can override the initial options supplied to withAxios at any time by passing prop to your wrapped component. See below on how this works.

constMyComponent=withAxios({    url'/api/user'    params{id"12345"}})(classMyComponentRawextendsReact.Component{render(){const{error,response,isLoading,makeRequest,axios}=this.propsif(error){return(<div>Something bad happened{error.message}</div>)}elseif(isLoading){return(<divclassName="loader"></div>)}elseif(response !==null){return(<div>{response.data.message}</div>)}returnnull}})

Related

  • Tutorial

    In this tutorial, you’ll share state across multiple components using React context. React context is an interface for sharing information with other components without explicitly passing the data as props. This means that you can share information between a parent component and a deeply nested child component, or store site-wide data in a single place and access them anywhere in the application. To illustrate this, this tutorial will create a website where users can build custom salads.

  • Tutorial

    React Hooks are a broad set of tools in the React front-end JavaScript library that run custom functions when a component’s props change. Since this method of state management doesn’t require you to use classes, developers can use Hooks to write shorter, more readable code that is easy to share and maintain. Throughout this tutorial, you’ll learn how to set state using the useState and useReducer Hooks, using a product page component with a shopping cart as an example.

  • Tutorial

    In React, state refers to a structure that keeps track of how data changes over time in your application. Managing state is a crucial skill in React because it allows you to make interactive web applications. In this tutorial, you’ll run through an example of managing state on class-based components. This tutorial will first show you how to set state using a static value and then how to set a state as the current state, using a product page component as an example.

  • Tutorial
    How To Style React Components

    In this tutorial, you’ll learn three different ways to style React components: plain Cascading Style Sheets (CSS), inline styles with JavaScript-style objects, and JSS, a library for creating CSS with JavaScript. To illustrate these methods, you’ll build an example Alert component that will either show a success style or an error style depending on the prop. You will then refactor it using each of the styling options to see the similarities and differences between each.

Cancellation

You can cancel a request using a cancel token.

You can create a cancel token using the factory as shown below:

constCancelToken=axios.CancelToken;constsource=CancelToken.source();axios.get('/user/12345',{  cancelTokensource.token}).catch(function(thrown){if(axios.isCancel(thrown)){console.log('Request canceled',thrown.message);}else{}});axios.post('/user/12345',{  name'new name'},{  cancelTokensource.token})source.cancel('Operation canceled by the user.');

You can also create a cancel token by passing an executor function to the constructor:

constCancelToken=axios.CancelToken;let cancel;axios.get('/user/12345',{  cancelTokennewCancelToken(functionexecutor(c){    cancel = c;})});cancel();

Interceptors

You can intercept requests or responses before they are handled by or .

axios.interceptors.request.use(function(config){return config;},function(error){returnPromise.reject(error);});axios.interceptors.response.use(function(response){return response;},function(error){returnPromise.reject(error);});

If you may need to remove an interceptor later you can.

var myInterceptor =axios.interceptors.request.use(function(){});axios.interceptors.request.eject(myInterceptor);

You can add interceptors to a custom instance of axios.

var instance =axios.create();instance.interceptors.request.use(function(){});

Отказ от тестов (или их недостаточное количество)

Если бы мне давали по рублю за каждый проект, который я просмотрел и где единственным тестом был тот, что является по умолчанию в create-react-app, я не писал бы эту статью. А, наверное, потягивал сейчас дайкири где-нибудь на пляже.

Что же такого в тестировании, что так пугает джунов? Я думаю, причина заключается в нетривиальности тестирования компонентов, особенно при условии их постоянного развития и роста комплексности. Часто вижу, как младшие программисты пишут юнит-тесты для каких-то определенных чистых функций, но терпят неудачу в случае, когда нужно написать интеграционный тест для целого компонента.

Может быть, заглушки сбивают их с толку? Или они испытывают сложности с тем, что следует тестировать и что нет?

Давайте взглянем на компонент, который я только что написал. Это очень простая форма входа, где пользователь должен ввести свой логин и пароль. Когда последний подтверждает введенную информацию, мы делаем вызов API и в случае, если ответ положительный, направляем клиента на другую страницу.

Так как же протестировать данную форму?

Первым делом давайте взглянем, каким образом наш пользователь будет взаимодействовать с ней.

  1. Пользователь вводит свои данные.
  2. Пользователь нажимает на кнопку подтверждения.
  3. Пользователь перенаправляется на страничку «home».

Это и есть все то, что нам нужно протестировать.

Ниже я написал один из тест-кейсов для данного компонента. Можете ли вы предложить какие-нибудь еще сценарии, которые было бы полезно протестировать?

Prerequisites

React is a JavaScript library and we’ll use the create-react-app tool for creating a React project. As such; you will need to have the following prerequisites to be able to following this tutorial step by step.

  • Knowledge of JavaScript since React is based on JS,
  • Node and NPM installed on your development system. This is required to install and use the tool — The official tool for creating React projects, serve them locally and build them for production. You can install Node and NPM by simply downloading the binaries for your system from the official website. You can also use NVM install and manage multiple Node versions in your system.

Now, if you have these prerequisites; let’s get started with our tutorial!

Server Side Rendering

seamlessly supports server side rendering scenarios, by preloading data on the server and providing the data to the client, so that the client doesn’t need to reload it.

  1. the React component tree is rendered on the server
  2. HTTP requests are executed on the server
  3. the server code awaits in order to obtain a serializable representation of the request-response cache
  4. the server injects a JSON-serialized version of the cache in a global variable
  5. the client hydrates the cache from the global variable before rendering the application using
<script>window.__AXIOS_HOOKS_CACHE__={{{cache}}}</script>
import{serializeCache}from'axios-hooks'router.use(async(req,res)=>{constindex=fs.readFileSync(`${publicFolder}/index.html`,'utf8')consthtml=ReactDOM.renderToString(<App >)constcache=awaitserializeCache()res.send(    index.replace('{{{html}}}', html).replace('{{{cache}}}',JSON.stringify(cache).replace(<g,'\\u003c')))})
import{loadCache}from'axios-hooks'loadCache(window.__AXIOS_HOOKS_CACHE__)deletewindow.__AXIOS_HOOKS_CACHE__ReactDOM.hydrate(<App >,document.getElementById('root'))

Handling Errors

axios.get('/user/12345').catch(function(error){if(error.response){console.log(error.response.data);console.log(error.response.status);console.log(error.response.headers);}elseif(error.request){console.log(error.request);}else{console.log('Error',error.message);}console.log(error.config);});

Using the config option, you can define HTTP code(s) that should throw an error.

axios.get('/user/12345',{validateStatusfunction(status){return status <500;}})

Using you get an object with more information about the HTTP error.

axios.get('/user/12345').catch(function(error){console.log(error.toJSON());});

Handling Errors

axios.get('/user/12345').catch(function(error){if(error.response){console.log(error.response.data);console.log(error.response.status);console.log(error.response.headers);}elseif(error.request){console.log(error.request);}else{console.log('Error',error.message);}console.log(error.config);});

Using the config option, you can define HTTP code(s) that should throw an error.

axios.get('/user/12345',{validateStatusfunction(status){return status <500;}})

Using you get an object with more information about the HTTP error.

axios.get('/user/12345').catch(function(error){console.log(error.toJSON());});

Base Example


There are many times when building application for the web that you may want to consume and display data from an API. There are several ways to do so, but a very popular approach is to use axios, a promise-based HTTP client.

In this exercise, we’ll use the CoinDesk API to walk through displaying Bitcoin prices, updated every minute. First, we’d install axios with either npm/yarn or through a CDN link.

There are a number of ways we can request information from the API, but it’s nice to first find out what the shape of the data looks like, in order to know what to display. In order to do so, we’ll make a call to the API endpoint and output it so we can see it. We can see in the CoinDesk API documentation, that this call will be made to . So first, we’ll create a data property that will eventually house our information, and we’ll retrieve the data and assign it using the lifecycle hook:

new Vue({  el: '#app',  data () {    return {      info: null    }  },  mounted () {    axios      .get('https://api.coindesk.com/v1/bpi/currentprice.json')      .then(response => (this.info = response))  }})
<div id="app">  {{ info }}</div>

And what we get is this:

See the Pen First Step Axios and Vue by Vue (@Vue) on CodePen.

Excellent! We’ve got some data. But it looks pretty messy right now so let’s display it properly and add some error handling in case things aren’t working as expected or it takes longer than we thought to get the information.

Config Defaults

You can specify config defaults that will be applied to every request.

axios.defaults.baseURL='https://api.example.com';axios.defaults.headers.common'Authorization'=AUTH_TOKEN;axios.defaults.headers.post'Content-Type'='application/x-www-form-urlencoded';
var instance =axios.create({  baseURL'https://api.example.com'});instance.defaults.headers.common'Authorization'=AUTH_TOKEN;

Config will be merged with an order of precedence. The order is library defaults found in , then property of the instance, and finally argument for the request. The latter will take precedence over the former. Here’s an example.

var instance =axios.create();instance.defaults.timeout=2500;instance.get('/longRequest',{  timeout5000});

The Cookbook vs the Guide

How is the cookbook different from the guide? Why is this necessary?

  • Greater Focus: In the guide, we’re essentially telling a story. Each section builds on and assumes knowledge from each previous section. In the cookbook, each recipe can and should stand on its own. This means recipes can focus on one specific aspect of Vue, rather than having to give a general overview.

  • Greater Depth: To avoid making the guide too long, we try to include only the simplest possible examples to help you understand each feature. Then we move on. In the cookbook, we can include more complex examples, combining features in interesting ways. Each recipe can also be as long and detailed as it needs to be, in order to fully explore its niche.

  • Teaching JavaScript: In the guide, we assume at least intermediate familiarity with ES5 JavaScript. For example, we won’t explain how works in a computed property that filters a list. In the cookbook however, essential JavaScript features (including ES6/2015+) can be explored and explained in the context of how they help us build better Vue applications.

  • Exploring the Ecosystem: For advanced features, we assume some ecosystem knowledge. For example, if you want to use single-file components in Webpack, we don’t explain how to configure the non-Vue parts of the Webpack config. In the cookbook, we have the space to explore these ecosystem libraries in more depth — at least to the extent that is universally useful for Vue developers.

With all these differences, please note that the cookbook is still not a step-by-step manual. For most of its content, you are expected to have a basic understanding of concepts like HTML, CSS, JavaScript, npm/yarn, etc.

Custom Axios Instance

Create an axios instance

constaxiosInstance=axios.create({  baseURL'/api/',  timeout2000,  headers{'X-Custom-Header''foobar'}});

Pass down through a provider

<AxiosProviderinstance={axiosInstance}><Geturl="test">{(error, response, isLoading, makeRequest, axios)=>{...}}</Get></AxiosProvider>

Or pass down through props

<Geturl="test"instance={axiosInstance}>{(error, response, isLoading, makeRequest, axios)=>{...}}</Get>

Retrieve from custom provider (when you need to directly use axios). The default instance will be passed if not inside an .

<AxiosProviderinstance={axiosInstance}><MyComponent/></AxiosProvider>

С этим читают