Cannot get uploaded image downloadURL?

Ionic Framework ionic-v3
1

I am trying to upload image to firebase. I can successfully upload the image . But the problem is i cannot get the uploaded image’s url. because the promise takes longer and my data passes to the db faster than the image;s url response. here is my code:


	post_news(form: NgForm){
		
		this.title = form.value.title;
		this.content = form.value.content;
		this.category = form.value.category;
		
		
		console.log(this.capturedimage1);
		
		
		if(this.capturedimage1 !== ''){
			
			//console.log('captured image is not empty');
			
	
			
		let storageRef = firebase.storage().ref();
		
		const filename = Math.floor(Date.now() / 1000);
		
		const imageRef = storageRef.child(`images/${filename}.jpg`);
		
		imageRef.putString(this.capturedimage1, firebase.storage.StringFormat.DATA_URL).then(function(data){
			
			
			this.imageref1 = data.downloadURL;
			
			
			
			
			
			let alert = this.alertCtrl.create({
				
				title: 'uploadedimage',
				subTitle: data.downloadURL,
				buttons: ['dismiss']
			});
			
			alert.present();
			
			
		});
			
		
		console.log(this.imageref1) -->this returns empty string...but the image is uploaded to firebase. 
	
		}

based on my google search…they say this is a promise and it is asynchronous(will not wait till it get the response) . if that’s the case how can i get the uploaded image’s downloadURL.