检查Geolocation是否被允许并获得Lat Lon [英] Check if Geolocation was allowed and get Lat Lon

问题描述

我正在构建一个客户端将在其页面上安装的小脚本。地理位置不是必需的，但如果它存在，那将是很好的。有没有办法让我检查客户页面是否已请求地理位置信息，如果用户选择允许获取lat& lon没有创建另一个提示？

I'm building a small script that clients will install on their page. Geolocation is not necessary for it, however if it exists it would be nice to have. Is there a way for me to check if the clients page has requested geolocation information and if the user selected allow get the lat & lon without creating another prompt?

推荐答案

使用地理定位API是不可能的，但可以使用新的权限API

It isn't possible with the geolocation API but it is possible with the new permission API

如果您想尝试接收坐标但又不想通过提示对话框打扰用户，此代码非常有用，因为坐标不是很重要，可能是退回到geoIP

This code is useful if you want to try to receive the coordinates but don't want to bother the user with a prompt dialog cuz the coordinates is not that important and may as well fallback to geoIP

function getCoords() {
  return new Promise((resolve, reject) =>
    navigator.permissions ?

      // Permission API is implemented
      navigator.permissions.query({
        name: 'geolocation'
      }).then(permission =>
        // is geolocation granted?
        permission.state === "granted"
          ? navigator.geolocation.getCurrentPosition(pos => resolve(pos.coords)) 
          : resolve(null)
      ) :

    // Permission API was not implemented
    reject(new Error("Permission API is not supported"))
  )
}

getCoords().then(coords => console.log(coords))

如果未授予权限，如果浏览器不支持某些javascript代码则转换错误，如果已被授予，则解析为坐标

This will resolve to null if permission hasn't been granted, cast a error if some javascript code wasn't supported by the browser and resolve to the coordinates if it has been granted

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