RNFirebase - database - js

lib/modules/database/snapshot.js

@@ -0,0 +1,86 @@
+/**
+ * @flow
+ */
+import Reference from './reference.js';
+import { isObject, deepGet, deepExists } from './../../utils';
+
+export default class Snapshot {
+  static key: String;
+  static value: Object;
+  static exists: boolean;
+  static hasChildren: boolean;
+  static childKeys: String[];
+
+  ref: Object;
+  key: string;
+  value: any;
+  exists: boolean;
+  priority: any;
+  childKeys: Array<string>;
+
+  constructor(ref: Reference, snapshot: Object) {
+    this.ref = ref;
+    this.key = snapshot.key;
+    this.value = snapshot.value;
+    this.exists = snapshot.exists || true;
+    this.priority = snapshot.priority === undefined ? null : snapshot.priority;
+    this.childKeys = snapshot.childKeys || [];
+  }
+
+  /*
+   * DEFAULT API METHODS
+   */
+
+  val() {
+    return this.value;
+  }
+
+  child(path: string) {
+    const value = deepGet(this.value, path);
+    const childRef = this.ref.child(path);
+    return new Snapshot(childRef, {
+      value,
+      key: childRef.key,
+      exists: value !== null,
+      childKeys: isObject(value) ? Object.keys(value) : [],
+    });
+  }
+
+  exists() {
+    return this.value !== null;
+  }
+
+  forEach(fn: (key: any) => any) {
+    return this.childKeys.forEach((key, i) => fn(this.child(key), i));
+  }
+
+  getPriority() {
+    return this.priority;
+  }
+
+  hasChild(path: string) {
+    return deepExists(this.value, path);
+  }
+
+  hasChildren() {
+    return this.numChildren() > 0;
+  }
+
+  numChildren() {
+    if (!isObject(this.value)) return 0;
+    return Object.keys(this.value).length;
+  }
+
+  /*
+   * EXTRA API METHODS
+   */
+  map(fn: (key: string) => mixed) {
+    const arr = [];
+    this.forEach((item, i) => arr.push(fn(item, i)));
+    return arr;
+  }
+
+  reverseMap(fn: (key: string) => mixed) {
+    return this.map(fn).reverse();
+  }
+}