Typescript: how to call a Javascript function with a callback

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

Well does it return a promise? If not than you probably need to do something like: cordova.plugins.icloudkv.load('key', () =>{}, () =>{}) ?? — epascarello
– epascarello, Commented Jul 13, 2017 at 13:35
You can't treat it like it's a promise if it's not. Either convert it to a promise (or observable - github.com/Reactive-Extensions/RxJS/blob/master/doc/api/core/…), or note that TS is just a subset of JS and call it exactly as you would have before, passing in a callback (arrow) function. — jonrsharpe
– jonrsharpe, Commented Jul 13, 2017 at 13:36
You can use methods on your class as success/error handlers. cordova.plugins.icloudkv.load('key', this.someClassMethod, this.someOtherClassMethod); — Alexander Staroselsky
– Alexander Staroselsky, Commented Jul 13, 2017 at 13:36
@AlexanderStaroselsky but note that this may behave in unexpected ways if you do so. — jonrsharpe
– jonrsharpe, Commented Jul 13, 2017 at 13:40

eko · Accepted Answer · 2017-07-13 13:35:51Z

2

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));
});

answered Jul 13, 2017 at 13:35

eko

40.8k11 gold badges79 silver badges104 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Richard Over a year ago

Thank you, I am just testing it, and will mark this as the answer if it works

user8086575 · Accepted Answer · 2017-07-13 13:43:51Z

1

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));
 });

answered Jul 13, 2017 at 13:43

user8086575

2 Comments

user8086575 Over a year ago

Also, bear in mind that with arrow functions this will have a different scope. My example assumes that this is the scope you want.

Richard Over a year ago

Thank you. You have the correct answer. But its the same as the answer fro someone who posted just before you, so I'll mark there's as the correct answer. You get an up vote haha

Duncan · Accepted Answer · 2017-07-13 14:19:38Z

0

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));
  });

answered Jul 13, 2017 at 14:19

Duncan

96.4k15 gold badges129 silver badges160 bronze badges

Collectives™ on Stack Overflow

Typescript: how to call a Javascript function with a callback

3 Answers 3

1 Comment

2 Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

2 Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related