Is there a way to write this database call into a function easily?

问题

All of the text in an application I'm working on is stored inside FireStore documents, so to retrieve it I use this bit of code

db.collection("language").document("kCreateNewAccount").get()
  .addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
      @Override
      public void onSuccess(DocumentSnapshot documentSnapshot) {
           String viewText = lan.equals("en") ? documentSnapshot.getString("en")
                                              : documentSnapshot.getString("es");
           createAccount.setText(viewText);
      }
  });

I've tried to put it into a function that takes the document name as a parameter and returns the correspondent string to avoid writing the same thing over and over again, to no avail, any help is welcome

回答1:

Firebase queries are async, you have to use a callback function.

Create Interface for callback

 public interface OnCompleteListener {
     void onComplete(String text);
 }

Create method for fetching text via document name

 public void getText(String document, final OnCompleteListener onCompleteListener) {
         db.collection("language").document(document).get()
                 .addOnSuccessListener(new OnSuccessListener<DocumentSnapshot>() {
                     @Override
                     public void onSuccess(DocumentSnapshot documentSnapshot) {
                         String viewText = lan.equals("en") ? documentSnapshot.getString("en")
                                 : documentSnapshot.getString("es");
                         onCompleteListener.onComplete(viewText);
                     }
                 });
     }

Call the method with your document name and specifying a listener

 getText("kCreateNewAccount", new OnCompleteListener() {
             @Override
             public void onComplete(String text) {
                 createAccount.setText(text);
             }
         });

来源：https://stackoverflow.com/questions/62482282/is-there-a-way-to-write-this-database-call-into-a-function-easily

标签

java

android

google-cloud-firestore