scrollToBottom option

scripts/background/actions.js

@@ -136,6 +136,19 @@ function queryUrl(tab, expected, log) {
     return sendMessage(tab, req, log, cond);
 }
 
+/**
+ * get the url of the target tab
+ * @param {any} tab target tab
+ * @param {string} expected if specified, queryUrl resolves only when tab url equals to expected
+ * @returns {Promise<string>} a promise of the url
+ */
+function scrollToBottom(tab) {
+    let req = {
+        action: ACTION_SCROLL_BOTTOM
+    }
+    return sendMessage(tab, req, 'Scroll to page bottom...');
+}
+
 async function createTab(url, active) {
     return new Promise((resolve, reject) => {
         chrome.tabs.create({

scripts/background/extractor.js

@@ -1,7 +1,8 @@
 class Extractor {
-    constructor() {
+    constructor(options) {
         this._tasks = [];
         this._running = false;
+        this._options = options;
     }
     /**
      * Add a task to Extractor. \n
@@ -10,7 +11,7 @@ class Extractor {
      * @param {...any} args itemsSelector, fieldSelectors, and more args to specify target urls.
      */
     task(...args) {
-        this._tasks.push(new Task(...args));
+        this._tasks.push(new Task(this._options, ...args));
         return this;
     }
     /**
@@ -32,7 +33,7 @@ class Extractor {
      */
     async restart(from = 0) {
         let id = this._checkTaskId(from, 0);
-        if (!id) return;
+        if (id < 0) return;
         for (let i = id; i < this._tasks.length; i++) {
             this._tasks[i].clean();
         }
@@ -68,10 +69,13 @@ class Extractor {
                     return task.execute(tab, undefined);
                 });
         }, Promise.resolve(undefined)).then(
-            () => this.save()
+            () => {
+                this._running = false;
+                this.save();
+            }
         ).catch(err => {
             this._running = false;
-            console.log(err)
+            console.log(err);
         });
     }
     /**
@@ -80,31 +84,34 @@ class Extractor {
      */
     save(taskid) {
         let id = this._checkTaskId(taskid, this._tasks.length - 1);
-        if (!id) return;
+        if (id < 0) return;
-        let result = new ExtractResult(this._tasks[id].results);
+        let results = this._tasks[id].results
+        results.unshift(this._tasks[id].fieldSelectors);
 
-        if (!result.data.length) {
+        let exResults = new ExtractResult(results);
+
+        if (!results.length) {
             console.log(`No result for task #${id}. Forget to call ".start()"?`);
             return;
         }
         let msg = `
-Please confirm to download (${result.data.length - 1} items)：
+Please confirm to download (${results.length - 1} items)：
 
-${result.toString(50) || "- Empty -"}
+${exResults.toString(50) || "- Empty -"}
 `.trim();
         if (confirm(msg)) {
-            saveFile(result, "text/csv");
+            saveFile(exResults, "text/csv");
         }
     }
     _checkTaskId(id, defaultId) {
         if (!this._tasks.length) {
             console.log("No task found.");
-            return 0;
+            return -1;
         }
-        if (defaultId && id === undefined) id = defaultId;
+        if (!isNaN(defaultId) && id === undefined) id = defaultId;
         if (isNaN(id) || id < 0 || id >= this._tasks.length) {
             console.log(`Invalid task id. Rang(0-${this._tasks.length - 1})`);
-            return 0;
+            return -1;
         }
         return id
     }

scripts/background/task.js

@@ -1,8 +1,6 @@
 class Task {
-    // _manager = undefined;
-    // _id = 0;
-    // _urls = [];
     _data = {};
+    _data_keys = [];
     /**
      * Create a task.
      * constructor(itemsSelector:string, fieldSelectors:string[])
@@ -11,9 +9,10 @@ class Task {
      * constructor(itemsSelector:string, fieldSelectors:string[], urls:string[])
      * @param {...any} args
      */
-    constructor(...args) {
+    constructor(options, ...args) {
         if (!testArgs(...args))
             throw new Error(`Invalid call arguments.\n\n${signitures}\n\n`);
+        this._options = options;
         this._itemsSelector = args.shift();
         this._fieldSelectors = args.shift();
         this._urls = parseUrls(...args);
@@ -25,39 +24,52 @@ class Task {
         return this._data;
     }
     get results() {
-        return this._urls.reduce((p, c) => {
+        return this._data_keys.reduce((p, c) => {
             return p.concat(this._data[c]);
         }, []);
     }
+    get fieldSelectors() {
+        return this._fieldSelectors;
+    }
     clean() {
         this._data = {};
     }
     async execute(tab, upstreamData) {
-        if (!tab) throw new Error("No tab to execute the task.");
+        if (!tab) return Promise.reject("No tab to execute the task.");
-        if (!this._urls.length) {
+        let urls = this._urls
+        if (!urls.length) {
             if (upstreamData) {
-                this._urls = parseUrls(upstreamData);
+                urls = parseUrls(upstreamData);
             } else {
-                this._urls = [await queryUrl(tab)];
+                urls = [await queryUrl(tab)];
             }
         }
-        return this._urls.reduce((p, url, i) => p.then(
+        let saveResult = (results, key) => {
+            this._data[key] = results;
+            this._data_keys.push(key);
+        }
+        return urls.reduce((p, url, i) => p.then(
             results => {
                 if (i > 0) {
                     if (!MSG_URL_SKIPPED.isEqual(results)) {
-                        let lastURL = this._urls[i - 1];
+                        let lastURL = urls[i - 1];
-                        this._data[lastURL] = results;
+                        saveResult(results, lastURL);
                     }
                 }
-                return this._data[url] ? MSG_URL_SKIPPED : redirectTab(tab, url).then(
+                if (this._data[url]) return MSG_URL_SKIPPED;
+                let pms = redirectTab(tab, url);
+                if (this._options["scrollToBottom"]) {
+                    pms = pms.then(() => scrollToBottom(tab));
+                }
+                return pms.then(
                     () => extractTabData(tab, this._itemsSelector, this._fieldSelectors)
                 );
             }
         ), Promise.resolve(null)).then(
             results => {
                 if (!MSG_URL_SKIPPED.isEqual(results)) {
-                    let lastURL = this._urls[this._urls.length - 1];
+                    let lastURL = urls[urls.length - 1];
-                    this._data[lastURL] = results;
+                    saveResult(results, lastURL);
                     return;
                 }
             }

scripts/content/content.js

@@ -1,29 +1,40 @@
-chrome.runtime.onMessage.addListener(
+(function () {
+    chrome.runtime.onMessage.addListener(
         function (request, sender, sendResponse) {
             if (!request.action) return;
             // console.log("Recieved request:",request);
+            doAction(request, sender).then(r => sendResponse && sendResponse(r));
+            // return true to indicate you wish to send a response asynchronously
+            return true;
+        }
+    );
+
+    async function doAction(request, sender) {
         switch (request.action) {
             case ACTION_EXTRACT:
                 let data = extract(request.itemsSelector, request.fieldSelectors);
-                if (sendResponse) sendResponse(data);
+                return data;
-                break;
             case ACTION_GOTO_URL:
                 window.location.replace(request.url);
-                if (sendResponse) sendResponse(request.url);
+                return request.url;
-                break;
             case ACTION_REPORT_IN:
-                if (sendResponse) sendResponse(request.action);
+                return request.action;
-                break;
             case ACTION_QUERY_URL:
-                if (sendResponse) sendResponse(window.location.href);
+                return window.location.href;
-                break;
+            case ACTION_SCROLL_BOTTOM:
+                return executeUntil(
+                    () => window.scrollTo(0, document.body.clientHeight),
+                    () => document.body.clientHeight - window.scrollY - window.innerHeight < 20,
+                    "Scroll to page bottom...",
+                    1000,
+                    10
+                )
             default:
                 break;
         }
     }
-);
 
-function extract(itemsSelector, fieldSelectors) {
+    function extract(itemsSelector, fieldSelectors) {
         // since some elements may be loaded asynchronously.
         // if one field is never found, we should return undefined,
         // so that senders can detect to retry until elements loaded.
@@ -50,4 +61,41 @@ function extract(itemsSelector, fieldSelectors) {
         // if it exists a field, which is not found in any row, the sender should retry.
         let shouldWait = fieldSelectors.reduce((p, c) => p || !fieldFound[c], false);
         return shouldWait ? MSG_ELEMENT_NOT_FOUND : results
-}
+    }
+
+    /**
+     * Repeatedly execute an function until the the detector returns true.
+     * @param {object} fn the function to execute
+     * @param {object} detector the detector.
+     * @param {string} log messages logged to console.
+     * @param {number} interval interval for detecting
+     * @param {number} limit max execute times of a function
+     * @return {Promise} a promise of the response.
+     */
+    function executeUntil(fn, detector, log, interval, limit) {
+        interval = interval || 500;
+        let count = 0;
+        return new Promise((resolve, reject) => {
+
+            loop();
+
+            async function loop() {
+                fn();
+                limit++;
+                if (limit && count >= limit) {
+                    reject(false);
+                }
+                setTimeout(() => {
+                    let flag = !detector || detector();
+                    if (log) console.log(log, flag ? '(OK)' : '(failed)');
+                    if (flag) {
+                        resolve(true);
+                    } else {
+                        loop();
+                    }
+                }, interval);
+            }
+        });
+    }
+
+})();

scripts/shared/common.js

@@ -6,6 +6,7 @@ const ACTION_EXTRACT = `${EXT_NAME}:Extract`;
 const ACTION_GOTO_URL = `${EXT_NAME}:GoToTUL`;
 const ACTION_REPORT_IN = `${EXT_NAME}:ReportIn`;
 const ACTION_QUERY_URL = `${EXT_NAME}:QueryURL`;
+const ACTION_SCROLL_BOTTOM = `${EXT_NAME}:ScrollToBottom`;
 
 const MSG_ELEMENT_NOT_FOUND = new ConstMessage(1, "No element found for at least one selector, maybe it's not loaded yet");
 const MSG_URL_SKIPPED = new ConstMessage(100, "Skipped current URL");