CODEWITHSUNDEEP
cordovaplugins
zhangv
zhangv

Reputation: 991

Cordova plugin get the async response from native function

In my case, I wanna build a simple plugin which:

  1. launch a native page
  2. (after user input something) callback to the cordova(js)

I did not found the way to handle the callback. I searched the cordova doc(the Echo example), the first part is quite straightforward. However, it does not mention the async callback.

Upvotes: 0

Views: 1108

Answers (1)

DaveAlden
DaveAlden

Reputation: 30356

You can send an async response by sending a "no result" response synchronously and preserving the Cordova callback in order to send the asynchrous result with it. For example:

Android:


public class MyPlugin extends CordovaPlugin {
    
    private static CallbackContext myAsyncCallbackContext = null;

    @Override
    public boolean execute(String action, JSONArray args, CallbackContext callbackContext) throws JSONException {
        if (action.equals("myAsyncFunction")) {
            // save the callback context
            someCallbackContext = myAsyncCallbackContext; 
            
            // Send no result for synchronous callback
            PluginResult pluginresult = new PluginResult(PluginResult.Status.NO_RESULT);
            pluginresult.setKeepCallback(true);
            callbackContext.sendPluginResult(pluginresult);
        }
        return true;
    }


    // Some async callback
    public void onSomeAsyncResult(String someResult) {
        if(myAsyncCallbackContext != null){
            // Send async result
            myAsyncCallbackContext.success(someResult);
            myAsyncCallbackContext = null;
        }
    }
}

iOS:


@interface MyPlugin : CDVPlugin
- (void)myAsyncFunction:(CDVInvokedUrlCommand *)command;
@end


@implementation MyPlugin

static NSString* myAsyncCallbackId = nil;

- (void)myAsyncFunction:(CDVInvokedUrlCommand *)command {
    // save the id
    myAsyncCallbackId = command.callbackId;

    // Send no result for synchronous callback
    CDVPluginResult* pluginResult = [CDVPluginResult resultWithStatus:CDVCommandStatus_NO_RESULT];
    [pluginResult setKeepCallbackAsBool:YES];
    [self.commandDelegate sendPluginResult:pluginResult callbackId:command.callbackId];
}

// Some async callback
- (void) didReceiveSomeAsyncResult:(NSString *)someResult {
    if(myAsyncCallbackId != nil){
        // Send async result
        CDVPluginResult* pluginResult = [CDVPluginResult resultWithStatus:CDVCommandStatus_OK messageAsString:someResult];
        [self.commandDelegate sendPluginResult:pluginResult callbackId:myAsyncCallbackId];
        myAsyncCallbackId = nil;
    }
}

@end

Upvotes: 3

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