2 files changed, 67 insertions, 3 deletions
diff --git a/graffiti.js b/graffiti.js
index 8875f8d..ad456b1 100644
--- a/graffiti.js
+++ b/graffiti.js
@@ -1,5 +1,5 @@
 import Auth from './src/auth.js'
-//import Collection from './src/collection.js'
+import GraffitiArray from './src/array.js'
 
 export default class {
 
@@ -240,8 +240,8 @@ export default class {
     const combinedMaps = Object.assign({},
       ...tags.map(tag=> this.tagMap[tag].objectMap))
 
-    // Return just the array
-    return Object.values(combinedMaps)
+    // Return an array wrapped with graffiti functions
+    return new GraffitiArray(this, ...Object.values(combinedMaps))
   }
 
   async subscribe(...tags) {
diff --git a/src/array.js b/src/array.js
new file mode 100644
index 0000000..f0c251f
--- /dev/null
+++ b/src/array.js
@@ -0,0 +1,64 @@
+// Extend the array class to expose update
+// functionality, plus provide some
+// useful helper methods
+export default class GraffitiArray extends Array {
+
+  constructor(graffiti, ...elements) {
+    super(...elements)
+    this.graffiti = graffiti
+  }
+
+  get mine() {
+    return this.filter(o=> o._by==this.graffiti.myID)
+  }
+
+  get notMine() {
+    return this.filter(o=> o._by!=this.graffiti.myID)
+  }
+
+  get authors() {
+    return [...new Set(this.map(o=> o._by))]
+  }
+
+  async removeMine() {
+    await Promise.all(
+      this.mine.map(async o=> await o._remove()))
+  }
+
+  #getProperty(obj, propertyPath) {
+    // Split it up by periods
+    propertyPath = propertyPath.match(/([^\.]+)/g)
+    // Traverse down the path tree
+    for (const property of propertyPath) {
+      obj = obj[property]
+    }
+    return obj
+  }
+
+  sortBy(propertyPath) {
+
+    const sortOrder = propertyPath[0] == '-'? -1 : 1
+    if (sortOrder < 0) propertyPath = propertyPath.substring(1)
+
+    return this.sort((a, b)=> {
+      const propertyA = this.#getProperty(a, propertyPath)
+      const propertyB = this.#getProperty(b, propertyPath)
+      return sortOrder * (
+        propertyA < propertyB? -1 : 
+        propertyA > propertyB?  1 : 0 )
+    })
+  }
+
+  groupBy(propertyPath) {
+    return this.reduce((chain, obj)=> {
+      const property = this.#getProperty(obj, propertyPath)
+      if (property in chain) {
+        chain[property].push(obj)
+      } else {
+        chain[property] = new GraffitiArray(this.graffiti, obj)
+      }
+      return chain
+    }, {})
+  }
+
+}