save and load state

scripts/background/extractor.js

@@ -1,9 +1,31 @@
+var __EXTRACTOR_STATE__ = "";
+
 class Extractor {
     constructor(options) {
         this._tasks = [];
         this._running = false;
         this._options = options;
     }
+    /**
+     * Save current state, in case we restore it later.
+     */
+    save() {
+        saveFile(JSON.stringify(this), 'application/json', 'state.json');
+    }
+    /**
+     * Restore previous state by loading from saved state.
+     */
+    load() {
+        if (!__EXTRACTOR_STATE__) {
+            console.log('No state found. \nPlease upload a saved state from the popup window first.');
+            return;
+        }
+        let state = JSON.parse(__EXTRACTOR_STATE__);
+        __EXTRACTOR_STATE__ = "";
+        this._options = state._options;
+        this._tasks = state._tasks.map(t => new Task(this._options, 'whaterver', ['whaterver']).load(t));
+        return this;
+    }
     /**
      * Add a task to Extractor. \n
      * One Extractor could has multiple tasks, which orgnized in a task chian.
@@ -76,7 +98,7 @@ class Extractor {
         }, Promise.resolve(undefined)).then(
             () => {
                 this._running = false;
-                this.save();
+                this.export();
             }
         ).catch(err => {
             this._running = false;
@@ -84,10 +106,10 @@ class Extractor {
         });
     }
     /**
-     * Save result of a task
+     * export result of a task to CSV
      * @param {number} taskid which task id to save, begins with 0
      */
-    save(taskid) {
+    export(taskid) {
         let id = this._checkTaskId(taskid, this._tasks.length - 1);
         if (id < 0) return;
         let results = this._tasks[id].results