How to Know If xpath exists or not:-CodePudding

can you help to fix that problem

How can i know and proccess this if the xpath doenst exists

Like... if doenst exista do this, if exists do that

Thank you everyone.

const puppeteer = require('puppeteer');

(async () => {
    // set some options (set headless to false so we can see 
    // this automated browsing experience)
    let launchOptions = { headless: false, args: ['--start-maximized'] };

    const browser = await puppeteer.launch(launchOptions);
    const page = await browser.newPage();

    // set viewport and user agent (just in case for nice viewing)
    await page.setViewport({width: 1366, height: 768});
    await page.setUserAgent('Mozilla/5.0 (X11; Linux x86_64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/78.0.3904.108 Safari/537.36');

    // go to the target web
    await page.goto('https://www.lamudi.co.id/newdevelopments/');

    // wait for element defined by XPath appear in page
    await page.waitForXPath("(//span[@class='CountTitle-number'])[1]");

    // evaluate XPath expression of the target selector (it return array of ElementHandle)
    let elHandle = await page.$x("(//span[@class='CountTitle-number'])[1]");

    // prepare to get the textContent of the selector above (use page.evaluate)
    let lamudiNewPropertyCount = await page.evaluate(el => el.textContent, elHandle[0]);

    console.log('Total Property Number is:', lamudiNewPropertyCount);

    // close the browser
    await browser.close();
})();

Like... if doenst exista do this, if exists do that...

CodePudding user response：

To check if an element exists in the DOM (Document Object Model) using an XPath expression in JavaScript, you can use the evaluate method of the document object. This method returns an iterator that you can use to iterate over the elements that match the XPath expression. The iterator will be empty if the XPath expression does not match any elements.

Here's an example of how you can check if an element exists using an XPath expression and the evaluate method:

function elementExists(xpath) {
    // Use the evaluate method to get an iterator over the elements that match the XPath expression
    var iterator = document.evaluate(xpath, document, null, XPathResult.ANY_TYPE, null);

    // Check if the iterator has any elements
    return iterator.iterateNext() != null;
}

// Example usage
if (elementExists("//div[@class='my-class']")) {
    // The element exists, do something
} else {
    // The element does not exist, do something else
}

Alternatively, you can use the querySelector or querySelectorAll document object methods to search for elements using a CSS selector. If the selector does not match any elements, these methods will return a null or an empty node list.

Here's an example of how you can check if an element exists using a CSS selector and the querySelector method:

function elementExists(selector) {
    // Use the querySelector method to get the first element that matches the selector
    var element = document.querySelector(selector);

    // Check if the element exists
    return element != null;
}

// Example usage
if (elementExists(".my-class")) {
    // The element exists, do something
} else {
    // The element does not exist, do something else
}

CodePudding user response：

could you try something like below.

----
----
let elHandle = await page.$x("(//span[@class='CountTitle-number'])[1]");

if(typeof elHandle === 'undefined') {
    console.log("it is not defined yet, do something");
} else if (elHandle.length > 0) {
    console.log("you have a greater than zero length array, do something");
}
----
----

hope it might help.