打字稿：如何使用回调调用Javascript函数

Question

I am using Ionic with Typescript. I need to access the following api :

load(key, successCallback/*(value)*/, failCallback)

In Typescript I do the following:

cordova.plugins.icloudkv.load('key').then((data) => {
    console.log(data);
    alert('load key: ' + JSON.stringify(data));
      });
    }
  }).catch((e) => {
    console.error(JSON.stringify(e));
    this.doAlert('iCloud: ' + JSON.stringify(e));
  });

However, the alert is never getting fired.

Question

Please can someone advise what's the best way to invoke the javascript function using typescript?

Thanks

Answer 1

According to the api you've provided your code should look more like:

cordova.plugins.icloudkv.load('key', 
  (data)=>{
    console.log(data);
    alert('load key: ' + JSON.stringify(data));
  }, (e)=>{
    console.error(JSON.stringify(e));
    this.doAlert('iCloud: ' + JSON.stringify(e));
});

Answer 2

Are you getting any errors in the console?

Your code assumes that load returns a Promise. See if this works, since the example explicitly asks for two callbacks in the load method:

cordova.plugins.icloudkv.load('key', (data) => {
        console.log(data);
        alert('load key: ' + JSON.stringify(data));
     }, (e) => {
         console.error(JSON.stringify(e));
         this.doAlert('iCloud: ' + JSON.stringify(e));
 });

Answer 3

If you prefer to work with a Promise even though the api doesn't use one then construct a Promise around the call:

new Promise((resolve, reject) => cordova.plugins.icloudkv.load('key', resolve, reject))
.then((data) => {
    console.log(data);
    alert('load key: ' + JSON.stringify(data));
      });
    }
  }).catch((e) => {
    console.error(JSON.stringify(e));
    this.doAlert('iCloud: ' + JSON.stringify(e));
  });