[android][database] final cleanup of RNFirebaseDatabaseReference for v3.

android/src/main/java/io/invertase/firebase/database/RNFirebaseDatabaseReference.java

@@ -1,8 +1,8 @@
 package io.invertase.firebase.database;
 
-import java.util.HashMap;
 import java.util.Map;
 import java.util.List;
+import java.util.HashMap;
 
 import android.util.Log;
 import android.support.annotation.Nullable;
@@ -32,12 +32,9 @@ class RNFirebaseDatabaseReference {
   private HashMap<String, ChildEventListener> childEventListeners;
   private HashMap<String, ValueEventListener> valueEventListeners;
 
-  Query getQuery() {
-    return query;
-  }
-
   /**
-   * TODO
+   * RNFirebase wrapper around FirebaseDatabaseReference,
+   * handles Query generation and event listeners.
    *
    * @param context
    * @param app
@@ -47,11 +44,22 @@ class RNFirebaseDatabaseReference {
    */
   RNFirebaseDatabaseReference(ReactContext context, String app, String refKey, String refPath, ReadableArray modifiersArray) {
     key = refKey;
+    query = null;
     appName = app;
     reactContext = context;
-    childEventListeners = new HashMap<String, ChildEventListener>();
+    childEventListeners = new HashMap<>();
-    valueEventListeners = new HashMap<String, ValueEventListener>();
+    valueEventListeners = new HashMap<>();
-    query = buildDatabaseQueryAtPathAndModifiers(refPath, modifiersArray);
+    buildDatabaseQueryAtPathAndModifiers(refPath, modifiersArray);
+  }
+
+
+  /**
+   * Used outside of class for keepSynced etc.
+   *
+   * @return Query
+   */
+  Query getQuery() {
+    return query;
   }
 
   /**
@@ -91,28 +99,32 @@ class RNFirebaseDatabaseReference {
   }
 
   /**
-   * TODO
+   * Add a ValueEventListener to the query and internally keep a reference to it.
    *
    * @param eventRegistrationKey
    * @param listener
    */
   private void addEventListener(String eventRegistrationKey, ValueEventListener listener) {
     valueEventListeners.put(eventRegistrationKey, listener);
+    query.addValueEventListener(listener);
+
   }
 
 
   /**
-   * TODO
+   * Add a ChildEventListener to the query and internally keep a reference to it.
    *
    * @param eventRegistrationKey
    * @param listener
    */
   private void addEventListener(String eventRegistrationKey, ChildEventListener listener) {
     childEventListeners.put(eventRegistrationKey, listener);
+    query.addChildEventListener(listener);
+
   }
 
   /**
-   * Listen for a single 'value' event from firebase.
+   * Listen for a single .once('value',..) event from firebase.
    *
    * @param promise
    */
@@ -135,7 +147,7 @@ class RNFirebaseDatabaseReference {
   }
 
   /**
-   * Listen for single 'child_X' event from firebase.
+   * Listen for single '.once(child_X, ...)' event from firebase.
    *
    * @param eventName
    * @param promise
@@ -190,7 +202,7 @@ class RNFirebaseDatabaseReference {
 
 
   /**
-   * Handles a React Native JS 'on' request and initializes listeners.
+   * Handles a React Native JS '.on(..)' request and initializes listeners.
    *
    * @param database
    * @param registration
@@ -219,7 +231,7 @@ class RNFirebaseDatabaseReference {
 
 
   /**
-   * TODO
+   * Add a native .on('child_X',.. ) event listener.
    *
    * @param registration
    * @param eventType
@@ -267,14 +279,14 @@ class RNFirebaseDatabaseReference {
       };
 
       addEventListener(eventRegistrationKey, childEventListener);
-      query.addChildEventListener(childEventListener);
     }
   }
 
   /**
-   * TODO
+   * Add a native .on('value',.. ) event listener.
-   * 
+   *
    * @param registration
+   * @param database
    */
   private void addValueEventListener(final ReadableMap registration, final RNFirebaseDatabase database) {
     final String eventRegistrationKey = registration.getString("eventRegistrationKey");
@@ -295,12 +307,12 @@ class RNFirebaseDatabaseReference {
       };
 
       addEventListener(eventRegistrationKey, valueEventListener);
-      query.addValueEventListener(valueEventListener);
     }
   }
 
-
   /**
+   * Handles value/child update events.
+   *
    * @param eventType
    * @param dataSnapshot
    * @param previousChildName
@@ -332,112 +344,182 @@ class RNFirebaseDatabaseReference {
     Utils.sendEvent(reactContext, "database_sync_event", event);
   }
 
-  private Query buildDatabaseQueryAtPathAndModifiers(String path, ReadableArray modifiers) {
+  /**
+   * @param path
+   * @param modifiers
+   * @return
+   */
+  private void buildDatabaseQueryAtPathAndModifiers(String path, ReadableArray modifiers) {
     FirebaseDatabase firebaseDatabase = RNFirebaseDatabase.getDatabaseForApp(appName);
 
-    Query query = firebaseDatabase.getReference(path);
+    query = firebaseDatabase.getReference(path);
     List<Object> modifiersList = Utils.recursivelyDeconstructReadableArray(modifiers);
 
-    // todo cleanup into utils
     for (Object m : modifiersList) {
-      Map<String, Object> modifier = (Map) m;
+      Map modifier = (Map) m;
       String type = (String) modifier.get("type");
       String name = (String) modifier.get("name");
 
       if ("orderBy".equals(type)) {
-        if ("orderByKey".equals(name)) {
+        applyOrderByModifier(name, type, modifier);
-          query = query.orderByKey();
-        } else if ("orderByPriority".equals(name)) {
-          query = query.orderByPriority();
-        } else if ("orderByValue".equals(name)) {
-          query = query.orderByValue();
-        } else if ("orderByChild".equals(name)) {
-          String key = (String) modifier.get("key");
-          query = query.orderByChild(key);
-        }
       } else if ("limit".equals(type)) {
-        int limit = ((Double) modifier.get("limit")).intValue();
+        applyLimitModifier(name, type, modifier);
-        if ("limitToLast".equals(name)) {
-          query = query.limitToLast(limit);
-        } else if ("limitToFirst".equals(name)) {
-          query = query.limitToFirst(limit);
-        }
       } else if ("filter".equals(type)) {
-        String valueType = (String) modifier.get("valueType");
+        applyFilterModifier(name, modifier);
-        String key = (String) modifier.get("key");
-        if ("equalTo".equals(name)) {
-          if ("number".equals(valueType)) {
-            double value = (Double) modifier.get("value");
-            if (key == null) {
-              query = query.equalTo(value);
-            } else {
-              query = query.equalTo(value, key);
-            }
-          } else if ("boolean".equals(valueType)) {
-            boolean value = (Boolean) modifier.get("value");
-            if (key == null) {
-              query = query.equalTo(value);
-            } else {
-              query = query.equalTo(value, key);
-            }
-          } else if ("string".equals(valueType)) {
-            String value = (String) modifier.get("value");
-            if (key == null) {
-              query = query.equalTo(value);
-            } else {
-              query = query.equalTo(value, key);
-            }
-          }
-        } else if ("endAt".equals(name)) {
-          if ("number".equals(valueType)) {
-            double value = (Double) modifier.get("value");
-            if (key == null) {
-              query = query.endAt(value);
-            } else {
-              query = query.endAt(value, key);
-            }
-          } else if ("boolean".equals(valueType)) {
-            boolean value = (Boolean) modifier.get("value");
-            if (key == null) {
-              query = query.endAt(value);
-            } else {
-              query = query.endAt(value, key);
-            }
-          } else if ("string".equals(valueType)) {
-            String value = (String) modifier.get("value");
-            if (key == null) {
-              query = query.endAt(value);
-            } else {
-              query = query.endAt(value, key);
-            }
-          }
-        } else if ("startAt".equals(name)) {
-          if ("number".equals(valueType)) {
-            double value = (Double) modifier.get("value");
-            if (key == null) {
-              query = query.startAt(value);
-            } else {
-              query = query.startAt(value, key);
-            }
-          } else if ("boolean".equals(valueType)) {
-            boolean value = (Boolean) modifier.get("value");
-            if (key == null) {
-              query = query.startAt(value);
-            } else {
-              query = query.startAt(value, key);
-            }
-          } else if ("string".equals(valueType)) {
-            String value = (String) modifier.get("value");
-            if (key == null) {
-              query = query.startAt(value);
-            } else {
-              query = query.startAt(value, key);
-            }
-          }
-        }
       }
     }
+  }
 
-    return query;
+  /* =================
+   *  QUERY MODIFIERS
+   * =================
+   */
+
+  /**
+   * @param name
+   * @param type
+   * @param modifier
+   */
+  private void applyOrderByModifier(String name, String type, Map modifier) {
+    switch (name) {
+      case "orderByKey":
+        query = query.orderByKey();
+        break;
+      case "orderByPriority":
+        query = query.orderByPriority();
+        break;
+      case "orderByValue":
+        query = query.orderByValue();
+        break;
+      case "orderByChild":
+        String key = (String) modifier.get("key");
+        query = query.orderByChild(key);
+    }
+  }
+
+  /**
+   * @param name
+   * @param type
+   * @param modifier
+   */
+  private void applyLimitModifier(String name, String type, Map modifier) {
+    int limit = ((Double) modifier.get("limit")).intValue();
+    if ("limitToLast".equals(name)) {
+      query = query.limitToLast(limit);
+    } else if ("limitToFirst".equals(name)) {
+      query = query.limitToFirst(limit);
+    }
+  }
+
+  /**
+   * @param name
+   * @param modifier
+   */
+  private void applyFilterModifier(String name, Map modifier) {
+    String valueType = (String) modifier.get("valueType");
+    String key = (String) modifier.get("key");
+    if ("equalTo".equals(name)) {
+      applyEqualToFilter(key, valueType, modifier);
+    } else if ("endAt".equals(name)) {
+      applyEndAtFilter(key, valueType, modifier);
+    } else if ("startAt".equals(name)) {
+      applyStartAtFilter(key, valueType, modifier);
+    }
+  }
+
+
+  /* ===============
+   *  QUERY FILTERS
+   * ===============
+   */
+
+  /**
+   * @param key
+   * @param valueType
+   * @param modifier
+   */
+  private void applyEqualToFilter(String key, String valueType, Map modifier) {
+    if ("number".equals(valueType)) {
+      double value = (Double) modifier.get("value");
+      if (key == null) {
+        query = query.equalTo(value);
+      } else {
+        query = query.equalTo(value, key);
+      }
+    } else if ("boolean".equals(valueType)) {
+      boolean value = (Boolean) modifier.get("value");
+      if (key == null) {
+        query = query.equalTo(value);
+      } else {
+        query = query.equalTo(value, key);
+      }
+    } else if ("string".equals(valueType)) {
+      String value = (String) modifier.get("value");
+      if (key == null) {
+        query = query.equalTo(value);
+      } else {
+        query = query.equalTo(value, key);
+      }
+    }
+  }
+
+  /**
+   * @param key
+   * @param valueType
+   * @param modifier
+   */
+  private void applyEndAtFilter(String key, String valueType, Map modifier) {
+    if ("number".equals(valueType)) {
+      double value = (Double) modifier.get("value");
+      if (key == null) {
+        query = query.endAt(value);
+      } else {
+        query = query.endAt(value, key);
+      }
+    } else if ("boolean".equals(valueType)) {
+      boolean value = (Boolean) modifier.get("value");
+      if (key == null) {
+        query = query.endAt(value);
+      } else {
+        query = query.endAt(value, key);
+      }
+    } else if ("string".equals(valueType)) {
+      String value = (String) modifier.get("value");
+      if (key == null) {
+        query = query.endAt(value);
+      } else {
+        query = query.endAt(value, key);
+      }
+    }
+  }
+
+  /**
+   * @param key
+   * @param valueType
+   * @param modifier
+   */
+  private void applyStartAtFilter(String key, String valueType, Map modifier) {
+    if ("number".equals(valueType)) {
+      double value = (Double) modifier.get("value");
+      if (key == null) {
+        query = query.startAt(value);
+      } else {
+        query = query.startAt(value, key);
+      }
+    } else if ("boolean".equals(valueType)) {
+      boolean value = (Boolean) modifier.get("value");
+      if (key == null) {
+        query = query.startAt(value);
+      } else {
+        query = query.startAt(value, key);
+      }
+    } else if ("string".equals(valueType)) {
+      String value = (String) modifier.get("value");
+      if (key == null) {
+        query = query.startAt(value);
+      } else {
+        query = query.startAt(value, key);
+      }
+    }
   }
 }