Send image from Flutter to callable cloud function

Question

I have callable cloud function used to register new Users. These users should also have a profile pic. I want to handle the whole registration process in my function and not from my client, so I want to send the image picked by the user to the function and upload it from there.

How do I send the image in the json data argument?

Solution

You have to upload the image from the client side. There is no way to send image data from client to Could Function without uploading. You can do following things:

• Upload the image from the client side and save the download url to Cloud Firestore.
• Use a Cloud Function Trigger to execute onDoumentCreated() and get the newly uploaded image url. Here you can do many things like cropping or compressing, generating thumbnails as you want.
• Complete the registration from Cloud Function.