3 files changed, 80 insertions, 1 deletions
diff --git a/src/fields/AudioField.ts b/src/fields/AudioField.ts
new file mode 100644
index 000000000..aefcc15c1
--- /dev/null
+++ b/src/fields/AudioField.ts
@@ -0,0 +1,31 @@
+import { BasicField } from "./BasicField";
+import { Field, FieldId } from "./Field";
+import { Types } from "../server/Message";
+
+export class AudioField extends BasicField<URL> {
+    constructor(data: URL | undefined = undefined, id?: FieldId, save: boolean = true) {
+        super(data == undefined ? new URL("http://techslides.com/demos/samples/sample.mp3") : data, save, id);
+    }
+
+    toString(): string {
+        return this.Data.href;
+    }
+    
+    
+    ToScriptString(): string {
+        return `new AudioField("${this.Data}")`;
+    }
+
+    Copy(): Field {
+        return new AudioField(this.Data);
+    }
+
+    ToJson(): { type: Types, data: URL, _id: string } {
+        return {
+            type: Types.Audio,
+            data: this.Data,
+            _id: this.Id
+        }
+    }
+
+}
+\ No newline at end of file
diff --git a/src/fields/ListField.ts b/src/fields/ListField.ts
index a71325a65..ce32da0a6 100644
--- a/src/fields/ListField.ts
+++ b/src/fields/ListField.ts
@@ -70,7 +70,25 @@ export class ListField<T extends Field> extends BasicField<T[]> {
     init(callback: (field: Field) => any) {
         Server.GetFields(this._proxies, action((fields: { [index: string]: Field }) => {
             if (!this.arraysEqual(this._proxies, this.Data.map(field => field.Id))) {
-                this.data = this._proxies.map(id => fields[id] as T)
+                var dataids = this.data.map(d => d.Id);
+                var added = this.data.length == this._proxies.length - 1;
+                var deleted = this.data.length > this._proxies.length;
+                for (let i = 0; i < dataids.length && added; i++)
+                    added = this._proxies.indexOf(dataids[i]) != -1;
+                for (let i = 0; i < this._proxies.length && deleted; i++)
+                    deleted = dataids.indexOf(this._proxies[i]) != -1;
+                if (added) { // if only 1 items was added
+                    for (let i = 0; i < this._proxies.length; i++)
+                        if (dataids.indexOf(this._proxies[i]) === -1)
+                            this.Data.splice(i, 0, fields[this._proxies[i]] as T);
+                } else if (deleted) { // if only items were deleted
+                    for (let i = this.data.length - 1; i >= 0; i--) {
+                        if (this._proxies.indexOf(this.data[i].Id) === -1) {
+                            this.Data.splice(i, 1);
+                        }
+                    }
+                } else // otherwise, just rebuild the whole list
+                    this.data = this._proxies.map(id => fields[id] as T)
                 observe(this.Data, () => {
                     this.updateProxies()
                     Server.UpdateField(this);
diff --git a/src/fields/VideoField.ts b/src/fields/VideoField.ts
new file mode 100644
index 000000000..5f4ae19bf
--- /dev/null
+++ b/src/fields/VideoField.ts
@@ -0,0 +1,30 @@
+import { BasicField } from "./BasicField";
+import { Field, FieldId } from "./Field";
+import { Types } from "../server/Message";
+
+export class VideoField extends BasicField<URL> {
+    constructor(data: URL | undefined = undefined, id?: FieldId, save: boolean = true) {
+        super(data == undefined ? new URL("http://techslides.com/demos/sample-videos/small.mp4") : data, save, id);
+    }
+
+    toString(): string {
+        return this.Data.href;
+    }
+
+    ToScriptString(): string {
+        return `new VideoField("${this.Data}")`;
+    }
+
+    Copy(): Field {
+        return new VideoField(this.Data);
+    }
+
+    ToJson(): { type: Types, data: URL, _id: string } {
+        return {
+            type: Types.Video,
+            data: this.Data,
+            _id: this.Id
+        }
+    }
+
+}
+\ No newline at end of file