use all values of ExractResult

scripts/extract.js

@@ -28,7 +28,7 @@ async function getData(itemsSelector, fieldSelectors, ...args) {
         if (arg instanceof Array) {
             urls = arg;
         } else if (arg instanceof ExractResult) {
-            urls = arg.column(0);
+            urls = arg.squash().filter(v=>!!v);
         } else {
             let urlTempl = arg;
             if (urlTempl) {

scripts/result.js

@@ -11,6 +11,9 @@ class ExractResult {
             i => this._data[i][index]
         );
     }
+    squash() {
+        return this._data.reduce((p, c) => p.concat(c), []);
+    }
     get data() {
         return this._data;
     }