@mirari/mp-common/src/scripts/api.js

小程序公共库

import utils from './utils'
import throttle from '../lib/lodash/throttle'

const DEFAULTS = {
  debug: false,
  autoLogin: true,  // token过期时自动尝试一次登录
  withCredentials: true, // 是否附带用户登录信息凭据
  baseURL: '',
  method: 'GET',  // 请求方式
  showLoading: false, // 是否遮罩
  showError: true, // 显示错误信息
  resultHandler: null // 查询结果处理
}

class APIError extends Error {
  constructor (result) {
    super(result.errmsg)
    this.name = 'APIError'
    this.code = result.code
    this.data = result.data
  }
}

const methodsWithData = ['POST', 'PUT', 'PATCH']
const methodsNoData = ['DELETE', 'GET', 'HEAD', 'OPTIONS']

// 将相对URL与baseURL合并
function combineURLs (baseURL, relativeURL) {
  return relativeURL
    ? baseURL.replace(/\/+$/, '') + '/' + relativeURL.replace(/^\/+/, '')
    : baseURL
}

// 是否绝对URL
function isAbsoluteURL (url) {
  // A URL is considered absolute if it begins with "<scheme>://" or "//" (protocol-relative URL).
  // RFC 3986 defines scheme name as a sequence of characters beginning with a letter and followed
  // by any combination of letters, digits, plus, period, or hyphen.
  return /^([a-z][a-z\d\+\-\.]*:)?\/\//i.test(url)
}

function encode (val) {
  return encodeURIComponent(val).replace(/%40/gi, '@').replace(/%3A/gi, ':').replace(/%24/g, '$').replace(/%2C/gi, ',').replace(/%20/g, '+').replace(/%5B/gi, '[').replace(/%5D/gi, ']')
}

function buildURL (url, params, paramsSerializer) {
  /*eslint no-param-reassign:0*/
  if (!params) {
    return url
  }

  var serializedParams
  if (paramsSerializer) {
    serializedParams = paramsSerializer(params)
  } else if (utils.isURLSearchParams(params)) {
    serializedParams = params.toString()
  } else {
    var parts = []

    utils.forEach(params, function serialize (val, key) {
      if (val === null || typeof val === 'undefined') {
        return
      }

      if (utils.isArray(val)) {
        key = key + '[]'
      }

      if (!utils.isArray(val)) {
        val = [val]
      }

      utils.forEach(val, function parseValue (v) {
        if (utils.isDate(v)) {
          v = v.toISOString()
        } else if (utils.isObject(v)) {
          v = JSON.stringify(v)
        }
        parts.push(encode(key) + '=' + encode(v))
      })
    })

    serializedParams = parts.join('&')
  }

  if (serializedParams) {
    url += (url.indexOf('?') === -1 ? '?' : '&') + serializedParams
  }

  return url
}

// 删除空参数
function deleteEmptyData (data) {
  if (data) {
    for (const key in data) {
      const val = data[key]
      if ((typeof val === 'undefined') || val === '' || val === null) {
        delete data[key]
      }
    }
  }
  return data
}

class API {
  constructor ({config, auth}) {
    this.defaults = Object.assign({}, DEFAULTS, config)
    this.auth = auth  // 鉴权实例
    // 节流封装，避免重复跳转
    this.showLogin = throttle(() => {
      auth.showLogin()
    }, 1000)
  }

  // 添加通用参数
  appendData (config) {
    if (!config.params) {
      config.params = {}
    }
    if (config.withCredentials) {
      if (!config.params.userId) {
        config.params.userId = this.auth.userId
      }
      if (!config.params.token) {
        config.params.token = this.auth.token
      }
    }
    return config
  }

  action (config) {
    config = Object.assign({}, this.defaults, config)

    // 删除空参数
    deleteEmptyData(config.params)
    deleteEmptyData(config.data)
    // 添加公共参数
    this.appendData(config)

    let {url, baseURL, params, data, method, header} = config
    // 拼接完整URL
    if (baseURL && !isAbsoluteURL(url)) {
      url = combineURLs(baseURL, url)
    }
    // POST方法时，需要将params拼到URL里
    // if (methodsWithData.includes(method) && params) {
    if (methodsWithData.indexOf(method) > -1 && params) {
      url = buildURL(url, params, config.paramsSerializer)
    }
    // GET方法时，需要将params改成data
    // if (methodsNoData.includes(method) && params) {
    if (methodsNoData.indexOf(method) > -1 && params) {
      data = params
      params = null
    }

    if (config.showLoading) {
      const {title='请稍候...', mask=true} = config.showLoading
      wx.showLoading({
        title,
        mask
      })
    }
    return new Promise((resolve, reject) => {
      wx.request({
        url,
        data,
        method,
        header,
        success: res => {
          if (config.showLoading) {
            wx.hideLoading()
          }
          if (res.statusCode >= 400) {
            console.error('wx.request fail [business]', config, res.statusCode, res.data)
            res.message = '网络貌似不给力~请检查你的网络后重试'
            reject(res)
          } else {
            let result = res.data
            const {code} = result
            if (code === '00') {
              resolve(result)
            } else {
              const e = new APIError(result)
              if (code === '01') {
                if (config.autoLogin) {
                  config.autoLogin = false
                  // 先尝试一次登录
                  this.auth.relogin().then(() => {
                    resolve(this.action(config))
                  })
                } else {
                  this.showLogin()
                  reject(e)
                }
              } else {
                if (config.showError) {
                  wx.showToast({
                    icon: 'none',
                    title: e.message
                  })
                }
                reject(e)
              }
            }
          }
        },
        fail: e => {
          if (config.showLoading) {
            wx.hideLoading()
          }
          // 格式化成标准error，便于异常处理
          if (e.errMsg) {
            e = new Error(e.errMsg)
          }
          console.error('wx.request fail [network]', config, e)
          if (config.showError) {
            wx.showToast({
              icon: 'none',
              title: e.message
            })
          }
          reject(e)
        },
        complete: () => {
        }
      })
    })
  }

  request (config) {
    return new Promise((resolve, reject) => {
      this.action(config).then(result => {
        let data = result.data
        if (config.resultHandler) {
          data = config.resultHandler(data)
        }
        resolve(data)
      }).catch(error => {
        reject(error)
      })
    })
  }

  paginationQuery (config, {pageSize, pageNum}) {
    return new Promise((resolve, reject) => {
      config.params = Object.assign({}, {
        pageSize: pageSize || 10,
        pageNum: pageNum || 1
      }, config.params)
      this.action(config).then((result) => {
        const {data, pagination} = result
        // 后端分页属性解耦
        let paging
        if (pagination) {
          paging = {
            list: data,  // 分页数据(required)
            total: pagination.totalSize,  // 总数(required)
            pageNum: pagination.pageNum || 1, // 当前页码(required) element分页插件的页码不允许为0，否则会无限触发跳页动作
            pageSize: pagination.pageSize, // 分页数设定值
            length: data.length,  // 分页数实际值(比如设定pageSize为10，但最后一页只有7条记录，size为7)
            pages: pagination.pages || 1, // 总页数
            startRow: pagination.startRow, // 当前起始索引
            endRow: pagination.endRow // 当前结尾索引
          }
        } else {
          paging = {
            list: data,  // 分页数据(required)
            total: 0,  // 总数(required)
            pageNum: 1, // 当前页码(required) element分页插件的页码不允许为0，否则会无限触发跳页动作
            pageSize: 0, // 分页数设定值
            length: 0,  // 分页数实际值(比如设定pageSize为10，但最后一页只有7条记录，size为7)
            pages: 1, // 总页数
            startRow: 0, // 当前起始索引
            endRow: 0 // 当前结尾索引
          }
        }
        if (config.resultHandler) {
          paging.list = config.resultHandler(paging.list)
        }
        resolve(paging)
      }).catch(error => {
        reject(error)
      })
    })
  }

  getUrl (config) {
    config = Object.assign({}, this.defaults, config)
    // 删除空参数
    deleteEmptyData(config.params)
    // 添加公共参数
    this.appendData(config)
    let {url, baseURL, params, paramsSerializer} = config

    // 拼接完整URL
    if (baseURL && !isAbsoluteURL(url)) {
      url = combineURLs(baseURL, url)
    }
    // 将params拼到URL里
    url = buildURL(url, params, paramsSerializer)

    return url
  }
}
API.buildURL = buildURL
export default API