Compare Product Prices Example (#78)

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Co-authored-by: R L Nabors <rachelnabors@users.noreply.github.com>

javascript-sdk/examples/compare-product-prices/README.md

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+# Example script: comparing product price across websites with AgentQL
+
+This example demonstrates how to compare product prices across websites with queryData() method.
+
+## Run the script
+
+- [Install AgentQL SDK](https://docs.agentql.com/javascript-sdk/installation)
+- Save this JavaScript file locally as **compare-product-prices.js**
+- Run the following command from the project's folder:
+
+```bash
+node compare-product-prices.js
+```
+
+## Play with the query
+
+Install the [AgentQL Debugger Chrome extension](https://docs.agentql.com/installation/chrome-extension-installation) to play with the AgentQL query. [Learn more about the AgentQL query language](https://docs.agentql.com/agentql-query/query-intro)

javascript-sdk/examples/compare-product-prices/compare-product-prices.js

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+const { wrap } = require('agentql');
+const { chromium } = require('playwright');
+
+// Set the URL to the desired website
+const BESTBUY_URL = 'https://www.bestbuy.com';
+const EBAY_URL = 'https://www.ebay.com';
+const TELQUEST_URL = 'https://www.telquestintl.com';
+
+// Define the queries to interact with the page
+const HOME_PAGE_QUERY = `
+{
+    search_input
+    search_button
+}
+`;
+
+const PRODUCT_INFO_QUERY = `
+{
+    product_price (for Nintendo Switch - OLed Model - w/ White Joy-Con)
+}
+`;
+
+/**
+ * Open the given URL in a new tab and fetch the price of the product.
+ */
+async function fetchPrice(context, sessionUrl) {
+  // Create a page in a new tab in the broswer context and wrap it to get access to the AgentQL's querying API
+  const page = wrap(await context.newPage());
+  await page.goto(sessionUrl);
+
+  // Search for the product
+  await page.waitForLoadState('networkidle');
+  const homeResponse = await page.queryElements(HOME_PAGE_QUERY);
+  await homeResponse.search_input.fill('Nintendo Switch - OLED Model White');
+  await homeResponse.search_button.click();
+
+  // Fetch the price data from the page
+  const data = await page.queryData(PRODUCT_INFO_QUERY);
+  return data.product_price;
+}
+
+/**
+ * Fetch prices concurrently in the same browser session from multiple websites.
+ */
+async function getPriceAcrossWebsites() {
+  const browser = await chromium.launch({ headless: false });
+  const context = await browser.newContext();
+
+  // Open multiple tabs in the same browser context to fetch prices concurrently
+  const [bestbuyPrice, ebayPrice, telquestPrice] = await Promise.all([
+    fetchPrice(context, BESTBUY_URL),
+    fetchPrice(context, EBAY_URL),
+    fetchPrice(context, TELQUEST_URL),
+  ]);
+
+  console.log(`
+    Price at BestBuy: ${bestbuyPrice}
+    Price at eBay: ${ebayPrice}
+    Price at Telquest: ${telquestPrice}
+    `);
+
+  await browser.close();
+}
+
+getPriceAcrossWebsites();