Add periodic tracking and periodic validation for payment pointers.

src/content_main.js

@@ -1,3 +1,6 @@
+const NEW_PAYMENT_POINTER_CHECK_RATE_MS = 1000; // 1 second
+const PAYMENT_POINTER_VALIDATION_RATE_MS = 1000 * 60 * 60; // 1 hour
+
 /**
  * Content scripts can only see a "clean version" of the DOM, i.e. a version of the DOM without
  * properties which are added by JavaScript, such as document.monetization!
@@ -32,17 +35,6 @@ main();
  * Main function to initiate the application.
  */
 async function main() {
-	// TODO: check payment pointer periodically for existence and validity
-	const {
-		isValid,
-		paymentPointer
-	} = await getAndValidatePaymentPointer();
-
-	setExtensionIconMonetizationState(isValid);
-
-	// paymentPointer will be null if it doesn't exist or is invalid
-	await storeDataIntoAkitaFormat({ paymentPointer: paymentPointer }, AKITA_DATA_TYPE.PAYMENT);
-
 	// Test storing assets
 	// await storeDataIntoAkitaFormat({
 	// 	paymentPointer: paymentPointer,
@@ -58,6 +50,8 @@ async function main() {
 	//	storeDataIntoAkitaFormat(null, AKITA_DATA_TYPE.PAYMENT);
 	//});
 
+	trackPaymentPointer();
+	handleUpdatingExtensionIconOnTabVisibilityChange();
 	await trackTimeOnSite();
 	await trackVisitToSite();
 
@@ -77,8 +71,11 @@ async function main() {
  *   If true, a pink $ badge is displayed. If false, just the dog face without the tongue is used as the icon.
  */
 function setExtensionIconMonetizationState(isCurrentlyMonetized) {
-	const webBrowser = chrome ? chrome : browser;
-	webBrowser.runtime.sendMessage({ isCurrentlyMonetized });
+	const tabIsVisible = !document.hidden;
+	if (tabIsVisible) {
+		const webBrowser = chrome ? chrome : browser;
+		webBrowser.runtime.sendMessage({ isCurrentlyMonetized });
+	}
 }
 
 /***********************************************************
@@ -114,12 +111,6 @@ async function trackTimeOnSite() {
 		} else {
 			// The page is now visible
 			docVisibleTime = getCurrentTime();
-
-			const {
-				isValid,
-				paymentPointer
-			} = await getAndValidatePaymentPointer();
-			setExtensionIconMonetizationState(isValid);
 		}
 	});
 
@@ -171,42 +162,134 @@ async function storeRecentTimeSpent(recentTimeSpent) {
 }
 
 /***********************************************************
- * Validate Payment Pointer
+ * Track and Validate Payment Pointer
  ***********************************************************/
 
 /**
- * Check for a monetization meta tag on the website and verify that
- * the payment pointer is valid (resolves to a valid SPSP endpoint).
- * 
- * TODO: use enum to indicate no meta tag, meta tag + valid endpoint,
- * meta tag + invalid endpoint.
- * 
- * @return {Promise<{ isPaymentPointerValid: boolean, paymentPointer:string}>} 
- * isPaymentPointerValid is true if both monetization is present and the payment endpoint is valid.
- * paymentPointer is the paymentPointer if it is found in the monetization meta tag, otherwise null.
+ * getPaymentPointerFromPage gets the payment pointer as a string from the monetization meta tag
+ * on the current page. If there is no monetization meta tag on the page, null is returned.
+ * For more info on the monetization meta tag:
+ *	- https://webmonetization.org/docs/getting-started
+ *	- https://webmonetization.org/specification.html#meta-tags-set
+ *
+ * @return {string|null} The payment pointer on the current page, or null if no meta tag is present.
  */
-async function getAndValidatePaymentPointer() {
-	const monetizationMeta = document.querySelector('meta[name="monetization"]');
-	let paymentPointer = (monetizationMeta) ? monetizationMeta.content : null;
-	let isValid = false;
+function getPaymentPointerFromPage() {
+	const monetizationMetaTag = document.querySelector('meta[name="monetization"]');
 
-	if (null === monetizationMeta) {
-		/* No monetization meta tag provided */
+	if (monetizationMetaTag) {
+		return monetizationMetaTag.content;
 	} else {
+		return null;
+	}
+}
+
+/**
+ * Checks every NEW_PAYMENT_POINTER_CHECK_RATE_MS milliseconds
+ * to see if a new payment pointer is added to the page. Calls `handleValidationAndSetExtensionIcon`
+ * to set the extension icon.
+ */
+function trackPaymentPointer() {
+	let cachedPaymentPointer = null;
+
+	setInterval(async () => {
+		const paymentPointerOnPage = getPaymentPointerFromPage();
+
+		const isNewPaymentPointer =
+			(paymentPointerOnPage !== null) &&
+			(paymentPointerOnPage !== cachedPaymentPointer);
+
+		if (isNewPaymentPointer) {
+			// Note that paymentPointerOnPage may be newly added to the current page and tab,
+			// but it is possible that this payment pointer was recently validated in another tab.
+			// Therefore it is necessary to use handleValidationAndSetExtensionIcon which checks the
+			// browser storage to see if the payment pointer has been recently validated.
+			handleValidationAndSetExtensionIcon(paymentPointerOnPage);
+			cachedPaymentPointer = paymentPointerOnPage;
+		}
+	}, NEW_PAYMENT_POINTER_CHECK_RATE_MS);
+}
+
+/**
+ * Ensures that the extension icon is updated to the correct state when switching between tabs.
+ */
+function handleUpdatingExtensionIconOnTabVisibilityChange() {
+	document.addEventListener('visibilitychange', (event) => {
+		const tabIsVisible = !document.hidden;
+
+		if (tabIsVisible) {
+			const paymentPointerOnPage = getPaymentPointerFromPage();
+			if (paymentPointerOnPage === null) {
+				setExtensionIconMonetizationState(false);
+			} else {
+				handleValidationAndSetExtensionIcon(paymentPointerOnPage);
+			}
+		}
+	});
+}
+
+/**
+ * Given a payment pointer, if it is valid, this function sets the extension icon to its
+ * monetized state and stores the payment pointer in browser storage,
+ * otherwise the extension icon is set to its unmonetized state.
+ *
+ * @param {string} paymentPointer the payment pointer to validate.
+ * @returns {Promise<>} a promise that resolves when validation is finished.
+ */
+async function handleValidationAndSetExtensionIcon(paymentPointer) {
+	if (await isPaymentPointerRecentlyValidated(paymentPointer)) {
+		setExtensionIconMonetizationState(true);
+	} else {
+		// validate if not validated recently
 		if (await isPaymentPointerValid(paymentPointer)) {
-			isValid = true;
+			// Store the payment pointer and the UTC timestamp for the time it was validated (now).
+			await storeDataIntoAkitaFormat({
+				paymentPointer: paymentPointer,
+				validationTimestamp: Date.now()
+			}, AKITA_DATA_TYPE.PAYMENT);
+			setExtensionIconMonetizationState(true);
+		} else {
+			setExtensionIconMonetizationState(false);
 		}
 	}
+}
 
-	return {
-		isValid,
-		paymentPointer
-	};
+/**
+ * Checks the browser storage to see if Akita has validated the given payment pointer and stored a
+ * validation timestamp for it recently.
+ *
+ * @param {string} paymentPointer the payment pointer to check.
+ * @returns {Promise<boolean>} resolves to true if there is a timestamp retrieved from storage and
+ * the timestamp is recent (less than PAYMENT_POINTER_VALIDATION_RATE_MS from present time).
+ * Resolves false otherwise.
+ */
+async function isPaymentPointerRecentlyValidated(paymentPointer) {
+	const originData = await loadOriginData(window.location.origin);
+	let validationTimestamp = null;
+	if (originData && originData.paymentPointerMap[paymentPointer]) {
+		// get validationTimestamp from originData under the given payment pointer.
+		validationTimestamp =
+			originData.paymentPointerMap[paymentPointer].validationTimestamp;
+	}
+	if (validationTimestamp === null) {
+		return false;
+	}
+
+	// check if validationTimestamp is recent.
+	const timeSinceLastValidated = Date.now() - validationTimestamp;
+	if (timeSinceLastValidated < PAYMENT_POINTER_VALIDATION_RATE_MS) {
+		return true;
+	} else {
+		return false;
+	}
 }
 
 /**
- * Check if a payment pointer is valid or not.
- * 
+ * Check if a payment pointer is valid (resolves to a valid SPSP endpoint).
+ * For more information on payment pointer resolution and validation see:
+ *	- https://paymentpointers.org/syntax-resolution/#requirements
+ *	- https://interledger.org/rfcs/0009-simple-payment-setup-protocol
+ *
  * @param {string} paymentPointer The paymentPointer found in a meta tag.
  * @return {Promise<boolean>} Whether or not the specified payment pointer is valid.
  */

src/data/AkitaOriginData.js

@@ -54,14 +54,17 @@ class AkitaOriginData {
 	/**
 	 * @param {{
 	 *	paymentPointer: String,
+	 *	validationTimestamp: Number,
 	 *	amount?: Number,
 	 *	assetScale?: Number,
 	 *	assetCode?: String
 	 * }} paymentData
 	 *	 This object may be created, or a Web Monetization event detail object can be used.
 	 *	 Pass in an object with just a paymentPointer to register a payment pointer for
 	 *	 the current website. Payment pointer should be validated first.
-	 *	 Additionally pass in assetCode, assetScale, and amount together to add to the
+	 *	 Optionally pass in validationTimestamp to set when the payment pointer was most
+	 *	 recently validated.
+	 *	 Optionally pass in assetCode, assetScale, and amount together to add to the
 	 *	 total amount sent to the current website.
 	 *
 	 *	 assetCode e.g. 'XRP', 'USD', 'CAD'
@@ -74,14 +77,22 @@ class AkitaOriginData {
 	updatePaymentData(paymentData) {
 		if (paymentData) {
 			const paymentPointer = paymentData.paymentPointer;
-			
+
 			if (paymentPointer) {
 				this.isCurrentlyMonetized = true;
 
 				if (!this.paymentPointerMap[paymentPointer]) {
 					this.paymentPointerMap[paymentPointer] = new AkitaPaymentPointerData(paymentPointer);
 				}
 
+				// Handling for optional argument: validationTimestamp
+				const validationTimestamp = paymentData.validationTimestamp;
+
+				if (validationTimestamp) {
+					this.paymentPointerMap[paymentPointer].setValidationTimestamp(validationTimestamp);
+				}
+
+				// Handling for the 3 optional arguments: amount, assetScale, and assetCode
 				const amount = paymentData.amount;
 				const assetScale = paymentData.assetScale;
 				const assetCode = paymentData.assetCode;

src/data/AkitaPaymentPointerData.js

@@ -4,6 +4,9 @@
  */
 class AkitaPaymentPointerData {
 	paymentPointer = null;
+	// The most recent time (UTC timestamp) when Akita validated the payment pointer
+	// For more info on payment pointer validation: see ../content_main.js, function isPaymentPointerValid
+	validationTimestamp = null;
 	// The type of each entry in sentAssetsMap is: WebMonetizationAsset
 	sentAssetsMap = {};
 
@@ -21,6 +24,7 @@ class AkitaPaymentPointerData {
 	 */
 	static fromObject(akitaPaymentPointerDataObject) {
 		const newPaymentPointerData = new AkitaPaymentPointerData(akitaPaymentPointerDataObject.paymentPointer);
+		newPaymentPointerData.validationTimestamp = akitaPaymentPointerDataObject.validationTimestamp;
 
 		for (const assetCode in akitaPaymentPointerDataObject.sentAssetsMap) {
 			newPaymentPointerData.sentAssetsMap[assetCode] = WebMonetizationAsset.fromObject(
@@ -30,6 +34,20 @@ class AkitaPaymentPointerData {
 		return newPaymentPointerData;
 	}
 
+	/**
+	 * When Akita validates a payment pointer, the time it was validated should be set using this
+	 * function. It is expected that payment pointers are validated by Akita often. In order to make
+	 * sure that validation occurs often, we keep track of the last time the payment pointer was
+	 * validated using validationTimestamp.
+	 *
+	 * For more info on payment pointer validation: see ./main.js, function isPaymentPointerValid
+	 *
+	 * @param {Number} validationTimestamp UTC Timestamp of last time payment pointer was validated.
+	 */
+	setValidationTimestamp(validationTimestamp) {
+		this.validationTimestamp = validationTimestamp;
+	}
+
 	/**
 	 * assetScale and amount e.g.
 	 *		if assetCode is 'USD', amount is 235, and assetScale is 3 then actual amount of

src/data/storage.js

@@ -85,18 +85,21 @@ async function storeDataIntoAkitaFormat(data, typeOfData) {
 
 /**
  * Update payment data in originData and in originStats.
- * 
+ *
  * @param {AkitaOriginData} originData The origin data to update.
  * @param {AkitaOriginStats} originStats The origin stats to update.
  * @param {{
  *	paymentPointer: String,
+ *	validationTimestamp: Number,
  *	amount?: Number,
  *	assetScale?: Number,
  *	assetCode?: String
  * }} paymentData
  * 	 This object may be created, or a Web Monetization event detail object can be used.
  * 	 Pass in an object with just a paymentPointer to register a payment pointer for
  * 	 the current website. Payment pointer should be validated first.
+ *	 Optionally pass in validationTimestamp to set when the payment pointer was most
+ *	 recently validated.
  * 	 Additionally pass in assetCode, assetScale, and amount together to add to the
  * 	 total amount sent to the current website.
  */