refactoring

scripts/background/actions.js

@@ -0,0 +1,168 @@
+/**
+ * Extract data from current page / multiple urls.
+ * getData(tab, itemsSelector:string, fieldSelectors:string[])
+ * getData(tab, itemsSelector:string, fieldSelectors:string[], url:string, from:number, to:number, interval:number)
+ * getData(tab, itemsSelector:string, fieldSelectors:string, url:string, pages:number[])
+ * getData(tab, itemsSelector:string, fieldSelectors:string[], urls:string[])
+ * getData(tab, itemsSelector:string, fieldSelectors:string[], urls:ExtractResult)
+ * getData(itemsSelector:string, fieldSelectors:string[])
+ * getData(itemsSelector:string, fieldSelectors:string[], url:string, from:number, to:number, interval:number)
+ * getData(itemsSelector:string, fieldSelectors:string, url:string, pages:number[])
+ * getData(itemsSelector:string, fieldSelectors:string[], urls:string[])
+ * getData(itemsSelector:string, fieldSelectors:string[], urls:ExtractResult)
+ * @param {...any} args
+ */
+async function getData(...args) {
+    let tab;
+    if (typeof args[0] !== 'string') tab = args.shift();
+    if (!testArgs(...args))
+        throw new Error(`Invalid call arguments.\n\n${signitures}\n\n`);
+    itemsSelector = args.shift();
+    fieldSelectors = args.shift();
+    let urls = parseUrls(...args);
+    let data = [];
+    if (!tab) tab = await getActiveTab(true) || await getActiveTab(false);
+    if (!tab) throw new Error("Cannot find active tab.");
+    return new Promise((resolve, reject) => {
+        let pms;
+        if (urls.length) {
+            pms = urls.reduce((p, url) => p.then(
+                results => {
+                    if (results) data.push(...results);
+                    return redirectTab(tab, url).then(
+                        () => extractTabData(tab, itemsSelector, fieldSelectors)
+                    );
+                },
+                () => p
+            ), Promise.resolve([]));
+        } else {
+            pms = extractTabData(tab, itemsSelector, fieldSelectors);
+        }
+        pms.then(
+            results => {
+                if (results) data.push(...results);
+                data.unshift(fieldSelectors);
+                resolve(new ExtractResult(data));
+            },
+            err => reject(err)
+        );
+    });
+}
+
+function parseUrls(...args) {
+    if (!args.length) return [];
+    let arg = args.shift();
+    if (arg instanceof Array) {
+        return arg;
+    } else if (arg instanceof ExtractResult) {
+        return arg.squash().filter(v => !!v);
+    } else {
+        let urlTempl = arg;
+        if (urlTempl) {
+            if (args[0] instanceof Array) {
+                return args[0].map(p => urlTempl.replace("${page}", p));
+            } else if (args.length >= 3) {
+                let urls = [];
+                let from = args.shift();
+                let to = args.shift();
+                let interval = args.shift();
+                for (let i = from; i <= to; i += interval) {
+                    urls.push(urlTempl.replace("${page}", i));
+                }
+                return urls;
+            }
+        }
+    }
+    return [];
+}
+
+function redirectTab(tab, url) {
+    let curUrl = "";
+    return queryUrl(tab, undefined, 'Query current url...')
+        .then(u => {
+            if (url !== u) {
+                curUrl = u;
+                let req = {
+                    action: ACTION_GOTO_URL,
+                    url: url
+                }
+                sendMessage(tab, req, `Goto url: ${url}`);
+            }
+        })
+        .then(() => queryUrl(tab, curUrl, 'Check if tab url matches expected...'))
+}
+
+/**
+ * extract data in from the target tab.
+ * @param {any} tab target tab
+ * @param {string} itemsSelector items selectors for selecting items (data rows)
+ * @param {Array<string>} fieldSelectors fields selectors for selecting fields (data columns) under each item
+ * @returns {Promise<string[]>} a promise of extracted data
+ */
+function extractTabData(tab, itemsSelector, fieldSelectors) {
+    let req = {
+        action: ACTION_EXTRACT,
+        itemsSelector: itemsSelector,
+        fieldSelectors: fieldSelectors
+    }
+    let cond = r => r !== undefined;
+    return sendMessage(tab, req, 'Extract data from the tab...', cond);
+}
+
+/**
+ * get report in from the target tab, usually used to detect if the content script is ready.
+ * @param {any} tab target tab
+ * @returns {Promise<string>} a promise of the report in message
+ */
+function reportIn(tab) {
+    let req = {
+        action: ACTION_REPORT_IN
+    }
+    let cond = r => r == req.action;
+    return sendMessage(tab, req, 'Check tab availability...', cond);
+}
+
+/**
+ * get the url of the target tab
+ * @param {any} tab target tab
+ * @param {string} urlExcluded if specified, queryUrl resolves only when response not equals to urlExcluded
+ * @returns {Promise<string>} a promise of the url
+ */
+function queryUrl(tab, urlExcluded, log) {
+    let req = {
+        action: ACTION_QUERY_URL
+    }
+    let cond = url => url && (!urlExcluded || (urlExcluded && urlExcluded != url));
+    return sendMessage(tab, req, log, cond);
+}
+
+async function createTab(url, active) {
+    return new Promise((resolve, reject) => {
+        chrome.tabs.create({
+            'url': url,
+            'active': active
+        }, function (tab) {
+            resolve(tab);
+        })
+    })
+}
+
+async function getActiveTab(currentWindow) {
+    return new Promise((resolve, reject) => {
+        chrome.tabs.query({
+            active: true,
+            currentWindow: currentWindow
+        }, function (tabs) {
+            resolve(tabs[0]);
+        })
+    })
+}
+
+async function getTabByID(id) {
+    return new Promise((resolve, reject) => {
+        chrome.tabs.get(id, function (tab) {
+            chrome.runtime.lastError;
+            resolve(tab);
+        })
+    })
+}