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    • Puppeteer pass function to evaluate.

  • Puppeteer pass function to evaluate evaluate returns a Promise, the function will wait for the promise to resolve and return its value. It's signature looks like this: Dec 23, 2018 · Puppeteer evaluate function. If the function passed to the page. Alternatively, you can specify the selector type using a prefix. evaluate() is isolated from the Node. evaluate returns a [Promise], then page. How to pass array and function to Page May 8, 2022 · Some of these functions are used by the main program (outside of puppeteer) too, since they are utility functions. evaluate((createHdpiCanvasCode) => { const createHdpiCanvas = new Function(`return ${createHdpiCanvasCode}`)(); const canvas = createHdpiCanvas(); return [canvas. evaluate(pageFunction[, args]) As you can see you can pass arguments to the pageFunction as additional paramateters when calling page. evaluate() method? How can I dynamically inject functions to evaluate using Puppeteer? Feb 10, 2019 · This function lets you run any JS function in the page context. To expose a function to the page from your Node. Wherever he has his await page. evaluate() method? Why can't I access 'window' in an exposeFunction() function with Oct 9, 2017 · Is it possible to pass a function to Puppeteer's page. I just get this error: Sep 18, 2021 · puppeteer give arguments evaluate pass args to evaluate puppeteer puppeteer evaluate parameter pass variable down to page. Here's a contrived example: Here's a contrived example: const obj = { thing: 'thing1', }; const myfunction = () => { return `great ${stuff}`; }; await page. Dec 8, 2018 · You could pass createHdpiCanvas as a parameter, however a function is not serialisable so you would have to do it yourself: page. If the function passed to page. May 18, 2021 · I'm using Puppeteer. evaluate puppeteer. yourCustomFunction = => { // your logic here } Add a script tag to your page and calling the function within evaluate: I am trying to pass a function as an argument to page. Aug 26, 2019 · The function you pass to evaluate is not a closure. 10. wait for setTImeout in page. Everything works fine unless I define the necessary variable before I call the . 14. value = keyword; }, keyword); And this code can click on the Google Search button and wait for the page to load. I was using something that looks like this below async function start() { let item = {cin: &quot;1234567&quot page. – Kevin. How to pass array and function to Page Mar 15, 2019 · I am trying to pass my custom object to page. evaluate(), but when I run the script it throws a following error: Error: Evaluation failed: TypeError: Cannot read property 'p1' of undefined. Apr 26, 2025 · Learn how to use Puppeteer's evaluate function to pass objects and execute scripts in the browser context. It states: pageFunction <function|string> Function to be evaluated in the page context We would like to show you a description here but the site won’t allow us. eval is not a function. Try this: Puppeteer: pass variable in . trim() in page. But you can define a function inside of the page. Dec 12, 2020 · Take a a look at the Puppeteer documentation for page. evaluate ( '1 + 2' ) ; Apr 13, 2019 · I've seen a good number of Puppeteer scripts in a state of confusion as the author tried to translate their working console code to page. evaluate was once capable of taking parameters to use inside the browser. I have a function called getContent() which I need to pass parameters to from a foreach loop in evaluate() but if I try to pass the function using that syntax ex: page. Dec 10, 2022 · This code can pass a variable inside evaluate(). Then, inside the page. trim() to execute in node/puppeteer context as exposeFunction allows. js (Puppeteer) Environment; Page DOM Environment; You should use page. Parameter. title ); This returns the document title from the puppeteer instance back to the node process. toString ( ) + ')();' ) ; const selector = '#someSelector'; // 2. Nov 19, 2021 · This is the function signature of puppeteer's page. Aug 20, 2019 · Puppeteer page. evaluate() returns a DOM element that is not serializable (it contains methods and circular references), it is replaced with an empty object. It signals to the web browser a string called a "fragment" that targets an anchor on a web page. innerHTML = "change to something" }, selector); In the above example I used s as the parameter, but passed in the value stored in selector. In the latest version args has been replaced with _args. Explore Teams Nov 6, 2023 · In this code, we define the text variable with the desired text that you want to pass to the page. g. Be aware, that functions defined there will only be present in the browser environment and not inside your Node. js script scope. evaluate querySelectorAll return empty objects You can just pass a string as the function body or a traditional function. e. evaluate would wait for the promise to resolve and return its value. evaluate() function, you can access this text using the text parameter. toString()). js window. Using page. evaluate resolves to undefined. Try Teams for free Explore Teams Nov 29, 2023 · Also, note that the function you pass to page. Easy fix: const result = await browser . evaluate() call where it expects a string. When navigating to Puppeteer’s website, the title element is evaluated as an empty Mar 31, 2021 · Puppeteer: use function inside page. evaluate() method? How can I dynamically inject functions to evaluate using Puppeteer? If the function passed to page. launch(). evaluate(): await myFunc(); return true; Page. js context and the browser context. Aug 25, 2021 · I am new to puppeteersharp and puppeteer in general. toString()); Dec 5, 2019 · How can I pass variable into an evaluate function that evaluates an async function using Puppeteer? Hot Network Questions How does the taste of a burrata made of buffalo milk differ from the taste of a burrata made of cow milk? Apr 5, 2020 · From the docs:. Conclusion Executing JavaScript within the page context while automating with Puppeteer is straightforward with the page. evaluate() function for use within the evaluated code. evaluate method to run JavaScript code in the context of the page? Jun 29, 2018 · In Puppeteer you can evaluate async functions: await page. – Jan 30, 2018 · I login to a site and it gives a browser cookie. evaluate accepts two arguments,pageFunction, and the rest are serialized args. For example: const selector = '#id' await page. How to await an async function evaluation in Nov 13, 2019 · The anonymous function which is the first argument to the page. Viewed 9k times Pass a function to evaluate() in puppeteer. Mar 4, 2019 · You can pass an object with options to puppeteer. selector to query the page for. When returning complex objects from page. However, as soon as I build the source with pkg - page. 5. evaluate() Function. Commented You can pass a string instead of a function (although functions are recommended as they are easier to debug and use with TypeScript): Example 2 const aHandle = await page . evaluate-1. I explored page. 0 Platform / OS version: MacOS 10. However, it's not immediately clear how to pass variables from Node to the page. If you use console. goto('blahblahblah. evaluate to extract any information necessary: Jan 30, 2018 · You can solve this problem by passing variables to the evaluate function. exposeFunction but that seems to be for an anonymous function that is created inline. evaluate a table into an array. Puppeteer page. Puppeteer version: 1. querySelector('input[name="q"]'). I need that until the javascript function is executed and finished it does not pass to another instruction, but I do not know the syntax to use. textContent, // 1. In simpler terms, running page. 0. exposeFunction is limited to serialized data as the other answer already points out. Dec 17, 2019 · I'm getting multiple errors with page. pageFunction. The evaluate() method The page. 0 Puppeteer - failed to pass variable into an evaluate function. evaluate so I can use it in there. Page. evaluateHandle is that evaluateHandle will return the value wrapped in an in-page object. evaluate method. Remarks . Jun 25, 2020 · Puppeteer version: 4. I do not understand why this is happening. exposeFunction() produce unhandled promise rejections; How to pass a function in Puppeteers . Could you help me? what do I have to put in order to get the content of the div resultDIV? Part of my code: Adds a function which would be invoked in one of the following scenarios: whenever the page is navigated. However, this might Mar 23, 2012 · My problem is that the code I pass to the webkit page is sandboxed, and so has no access to the variables of my main phantom script. Jan 24, 2020 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. You signed out in another tab or window. Waits for the provided function, pageFunction, to return a truthy value when evaluated in the page's context. js environment, which means it does not have access to variables from your Node. log() calls: Apr 25, 2020 · TypeError: page. evaluate; 与 page. Nov 5, 2017 · I am trying to evaluate a function with puppeteer but the callback is never firing (i am certain the host page is working as expected). most classes), then evaluate will _likely_ return some truncated value (or {}). Puppeteer allows evaluating JavaScript functions in the context of the page driven by Puppeteer: // Close browser. width, canvas. How would I go about this function? Sep 9, 2017 · To parse any data from a page you would rather wait for it to load completely and then use page. from(document. evaluate 的函数返回 Promise，该函数将等待 Promise 解析并返回其值。 ¥If the function passed to page. evaluate not running console. evaluate should accept the arguments which you are passing. js environment; you need to explicitly pass them as arguments. Ask Question Asked 6 years, 4 months ago. headline'). resolve(42); }`); (puppeteer will call . another-element") awai Jun 2, 2019 · You can only pass serializable data to the page. It means that the function cannot access scope variables or call other functions defined in your Puppeteer script, and you need to define the entire function logic within the function body. evaluate cannot exposeFunction with args. 15. json'); ? Page. Which is why I was thinking to have them defined in both places. evaluate() method is a powerful feature in Puppeteer that allows you to run JavaScript inside the context of the browser. Related questions. 0 Platform / OS version: Windo I can't figure out how to pass the logger object into page. Returns: Promise<Awaited<ReturnType<Func>>> The result of func. com' with the URL of the webpage you want to interact with. EvaluateFunctionAsync(@"async => { // await some promise }"); Dec 18, 2020 · I need to create a puppeteer script that will be able to send requests as well. exposeFunction() Pass a function to evaluate() in puppeteer. If the given function returns a promise, evaluate will wait for the promise to resolve. evaluate, i would like the function stated in the OP do the querySelect call inside the browser, while . page . Passing Puppeteer page as params in a function is not working as expected. 3. using arrow function into the return block of page. Feb 5, 2024 · On the other hand, Puppeteer uses object for passing options to methods. const title = await page . Although, it… Aug 18, 2020 · By reading the puppeteer's documentation, you can see where we can insert parameters. In this case, the function is invoked in the context of the newly attached frame. puppeteer. Quote from the docs: Sep 3, 2019 · His await function serpDesc would need to be contained in an async function. We can see that the parameters are a spreaded array (args) that is received in last. evaluate() when you are seeking to interact with the page directly in the page DOM environment by passing a function and returning a <Promise<Serializable>> which resolves to the return value of the passed function. Puppeteer - How to evaluate XPath which returns text? 1. Feb 16, 2022 · The only way I know how to make this work is to pass in a path to a file that contains your function to puppeteer. (see the docs for more information). It provides a powerful way to interact with the page's DOM and extract information. Undefined Variables The method adds a function called name on the page's window object. Make sure to replace 'https://example. and. toString() on your function to get the source, which might contain references to helpers used by babel, which aren't present in the page context) Aug 27, 2020 · you're not passing in a function but the result of the function, which is a boolean. So when you are using page. Pass a function to evaluate() in puppeteer. If you want to pass a parameter to a function via the query string of the URL, it should be URL escaped with percent encoding. The function is invoked after the document was created but before any of its scripts were run. – When trying to pass in a simple object into a async function that runs puppeteer, i get this error: (node:4000) UnhandledPromiseRejectionWarning: Error: Evaluation Jun 21, 2021 · Ask questions, find answers and collaborate at work with Stack Overflow for Teams. Jul 11, 2018 · Serializable|JSHandle> Arguments to pass to pageFunction returns: < Promise < Serializable >> Promise which resolves to the return value of pageFunction This method runs Array. exposeFunction() 绑定的函数会产生未处理的承诺拒绝; 暴露的函数 queryseldtcor 在 puppeteer 中不起作用; 如何动态注入函数以使用 Puppeteer 进行评估？ Oct 28, 2018 · I'm working with Node. It is returning undefined - which according to the docs I think is for a good reason (non-serializable). How to pass a function in Puppeteers . I imported the function in my test file and passed it as a variable through Is it possible to pass a function to Puppeteer's page. args. evaluate of puppeter script. Those could be the same Mar 28, 2019 · When you pass puppeteer a string, we try to evaluate it as an expression not a function definition. evaluate(() => startTheShow()) means there should be a startTheShow function in the page context which I'd assume there isn't any and the page context has no idea what startTheShow is. Here is the puppeteer function(th Mar 2, 2018 · In Pupeteer, I'd like to pass an arbitrary number of ElementHandle to the method evaluate in an array: const element1=await page. When working with Puppeteer for web automation, it's crucial to grasp the distinction between the Node. As moment is a function and a function cannot be serialized you cannot use it that easy. When called, the function executes puppeteerFunction in node. As it has previously been said, it's a pain not being able to select an element based on its text content (which often a lot), or to select nodes based on ancestors predicates ( for instant //*[@Class='whateverclass'][not(ancestor::div[@id='abcdef'])] ) If the function passed to the page. alljobs is an array I'm trying to push objects to. As document. — this can be mitigated a bit by using Function. querySelector(s) dom. evaluate(), but you can call another special method (page. Put what puppeteer needs in puppeteer and what the main program needs in that scope. Signature ¥If the function passed to page. Oct 9, 2017 · All I want is to be able to pass a parameterised function as a string to the page. js and returns a Promise which resolves to the return value of puppeteerFunction. Anyway, it turns out that Puppeteer’s website has an entry page, which immediately redirects us to the well-known website’s index page. If you want a "tricky" solution you cant try exposeFunction but usually is not a good way. log. 1 Nov 5, 2019 · I have some URL parameters that I need to pass to Puppeteer via query strings. type() in Nov 26, 2017 · Saved searches Use saved searches to filter your results more quickly Apr 8, 2020 · So, I have a function that returning page that needed by next function:. waitForFunction functions start failing wi Oct 14, 2020 · When the function finishes, it fills a div tag on that page. As a result, it doesn’t have access to variables defined in the parent scope. evaluateHandle returns a Promise, the function will wait for the promise to resolve and return its value. Did you mean page. evaluate() An object is OK to pass but can't seem to pass a function. You signed in with another tab or window. evaluate. await page. Aug 27, 2018 · First, it is important to understand that there are two main environments: Node. You switched accounts on another tab or window. Nov 20, 2020 · You're passing a function into the . evaluate() method in Pyppeteer takes a string of JavaScript. js and Puppeteer for the first time and can't find a way to output values from page. js version: v12. Oct 28, 2019 · To execute JavaScript code on your puppeteer instance, you can use the provided evaluate method. 你可以传递字符串而不是函数（尽管建议使用函数，因为它们更容易调试并与 TypeScript 一起使用）： If the function passed to page. querySelector(selector). Description. This is useful for parameterizing your scripts: const sum = await page. I want to pass the existing logger object that I already have instantiated. textContent. – ggorlen. This handle can be a JSHandle or an ElementHandle, depending on the return value of the function. evaluate((selector) => { // 3. I pass in an variable array that I would like to use to retrieve links from these sections in a drop down. evaluate(), you should include it as an additional parameter. evaluateHandle() and you want to get the console. evaluate() function allows you to execute custom JavaScript on a web page within the browser. If you post the predicted code i can suggest you a better way. Nov 30, 2023 · The Puppeteer page. Sep 16, 2020 · how do I call a function passing the page object outside async method in puppeteer. 13. async function browser(){ const browser = await puppeteer. evaluate() function is a versatile tool for executing JavaScript within a page's execution context. Here's the stripped down version of the code : let currentPost = 1; await page. js 库，提供了丰富的 API 接口，能够帮助开发者高效地处理动态网页数据。本文将重点讲解 Puppeteer 的 evaluate 函数，结合代理 IP 技术，演示如何采集目标网站（如界面新闻）上的文章标题和摘要。 Sep 20, 2020 · A page function is a function that Puppeteer (through NodeJS) turns into a string, sends to the browser, and then runs inside the Chromium instance. selector. I want to pass the result of that function into page. Ask Question Asked 2 years, 8 months ago. log() text from the browser context back to node, use the following code and make sure to set the listener before any console. But I think I see what you are getting at. exposeFunction), which expose your function as a global function (also available in as an attribute of your page window object), so you can call it when you are inside page. Puppeteer's page. We can pass a function as an argument to the evaluate function that will be executed within the page's context. launch({args: ['--no-sandbox Dec 27, 2024 · Passing Variables into Puppeteer's page. log('hello') in your page function, it will log it to the console in the browser. I have an array containing the variables i need to use but lets say i wanna check the second table manually using a variable, here's how i approached the problem Dec 18, 2019 · While learning and practicing with puppeteer I run into a problem that I thought was difficult to solve. page. On the host page a listener works like: Sep 11, 2019 · Hi I am working on a web scraping script, and I have a function that currently returns to me a string. I need this variable to be used inside the browser's context. We can create a simple wrapper or use browserify to overcome this problem for now. CSS selectors can be passed as-is and a Puppeteer-specific selector syntax allows querying by text, a11y role and name, and xpath and combining these queries across shadow roots. evaluate((a, b) => { return a + b; }, 1, 2); console. Try this way. Mar 20, 2022 · For instance, if i needed to do document. Evaluates a function in the page's context and returns the result. if you look at the example I showed of casperjs, you can see there is this line where you are basically executing a function on the browser scope. Modified 5 years ago. evaluate(function() { // this code has no access to foo console. Type. Aug 31, 2021 · puppeteer evaluate functional with callback. . calls because they thought they had to. In Puppeteer, the page. 1. 签名 ¥Signature You can pass a string instead of a function (although functions are recommended as they are easier to debug and use with TypeScript): Example 2 const aHandle = await page . launch() if you want to see it working with your own eyes. evaluate (() => document . evaluate() 10. evaluate, call the md5 function to hash a string and log the result to the console. querySelector('. the function to be evaluated in the page context. I'm trying to scrape a bunch of tables on a page with Puppeteer but the amount of tables varies each time and therefore i need to pass a variable into the page. evaluate and I don't understand why. evaluate returns a non-[Serializable] value, then page. read the passed data const lastUpdate = await page. For some reason pkg doesn't correctly interpret the contents of the callback. You cannot pass a function directly into page. Dec 13, 2022 · Puppeteer：在 . How do I scrape the page after entering await page. – Oct 15, 2019 · Puppeteer 是一个用于控制 Chromium 或 Chrome 浏览器的 Node. On the other hand, the page. For instance, if I +1 , I , would like too XPath selectors to be handled. Selector. Jan 8, 2018 · Puppeteer has changed the way evaluate works, the safest way to retrieve DOM elements is by creating a JSHandle, and passing that handle to the evaluate function: Jun 8, 2020 · I can think of two dubious and inconvenient solutions. When running the pageFunction, it Jan 2, 2020 · I've run into a situation that I do not understand. innerText) to avoid having to pass it as a second parameter. The code inside page. This makes it hard make the scraping code generic. An array of elements matching the given selector will be passed to the function as its first argument. evaluate(el => el. In these cases, you may prefer the evaluate approach, or only partially converting the browser code to Puppeteer code on an as-needed basis for specific trusted events. Dec 29, 2024 · I wouldn't call resorting to evaluate a hack, since Puppeteer doesn't pretend to offer helpers for everything, but you're right that abusing console. Pass it here }, selector); What's going on?. 1. Puppeteer: How to evaluate xpath with document. Params. Puppeteer: pass variable in . You can pass a string instead of a function (although functions are recommended as they are easier to debug and use with TypeScript): Example 1 Unfortunately, page. evaluate() this should work as well. 如果传递给 page. ReferenceError: alljobs is not defined. execute block. Jun 13, 2020 · Pass a function to evaluate() in puppeteer. May 16, 2019 · UPDATE I am running in docker and using puppeteer version 1. 53. As a rule of thumb, if the return value of the given function is more complicated than a JSON object (e. Aug 16, 2019 · If you're using a transpiler like babel you might need to pass the function as a string to page. 0; Platform / OS version: Windows 10; URLs (if applicable): Node. However, it’s not. trim() would be provided in another function efn as x=> x. 0 What steps will reproduce the problem? function inner { return 'h CSS selectors can be passed as-is and a Puppeteer-specific selector syntax allows querying by text, a11y role and name, and xpath and combining these queries across shadow roots. Modified 2 years, How to pass array and function to Page. The workaround I found is to save the arguments to a file, pass the file path to the browser, and then fetch it. Func | string. How can I pass an existing object into Puppeteer's page. I want to implement a functionality where if a certain value is found on page it should play a music. x and above - Jan 2020. evaluate()? You can call evaluate on the handle directly: someHandle. evaluate() function, you need to ensure that the variable is correctly referenced within the function. querySelectorAll(selector)) within the page and passes it as the first argument to pageFunction . evaluateHandle(pageFunction, args) Remarks: The only difference between page. Puppeteer: use function inside page. Apr 8, 2018 · I obviously don't want to have a bunch of functions with the selectors hard coded I want to pass it in to the page evaluate. Jan 1, 1970 · NOTE: This page was generated from the Puppet source code on 2022-02-07 10:05:45 -0800. exposeFunction capabilities. ¥Evaluates a function in the page's context and returns the result. Using eval() or Function() constructor inside the evaluated function and transfer the function code as a string (difficult for code writing, linting etc. This method allows you to compute MD5 hashes directly within the page context, leveraging Puppeteer's page. Here is a working snippet, don't hesitate to pass {headless: false} to puppeteer. : await page. I am trying to convert a function that is used in puppeteer to puppeteerSharp and i am wondering how to do it. evaluate((obj, function)=>{ const thing = myfunction; },(obj Jan 11, 2018 · Puppeteer: pass variable in . I go to a URL and it is a json response. Right not, it it not taking any arguments. puppeteer page. exposeFunction makes it easier to pass data back to Node from your MutationObserver or trigger a callback than console. evaluate to the outer scope. Feb 27, 2021 · I found something like that works for variable, but now i need to pass a function also. evaluate puppeteer pass function inside puppeteer evaluate puppeteer evaluate pass function evaluate puppeteer pass variables puppeteer evaluate pass global variable puppeteer evaluate pass element handle how to pass value Feb 16, 2018 · How to use imported function inside page. Mar 9, 2025 · Evaluate Function: Within page. To pass an argument to the function you provide to page. Aug 19, 2022 · Puppeteer page. evaluate in Puppeteer with Jest? 2. The evaluate function does not run when called. evaluate ( '1 + 2' ) ; You can pass a string instead of a function (although functions are recommended as they are easier to debug and use with TypeScript): Example 2 const aHandle = await page . evaluate((s) => { let dom = document. Works quite fast compared to what Puppeteer does. exposeFunction. multiplePositionsPerJob is a function that I've referenced with require in the file. Evaluation failed: ReferenceError: multiplePositionsPerJob is not defined. How c Mar 21, 2025 · Page Context Explained. This method is widely used for interacting with the web page as though a real user would, but through automated scripts. evaluate((keyword) => { document. Which I believe is some sort of serialization and deserialization. 0. evaluate() Puppeteer evaluate function; allow to pass a parameterized funciton as a string to page. use it here document. evaluate() method Evaluates a function in the page's context and returns the result. Signature The evaluate function in Puppeteer allows us to run JavaScript code within the context of a web page. Reload to refresh your session. Nov 29, 2024 · In Puppeteer, when you're passing a variable into the page. evaluate, e. whenever the child frame is attached or navigated. evaluate() is akin to opening Dev tools and writing set_calendar_date('1') there directly. Additional arguments to pass to pageFunction. prototype. evaluate, Puppeteer serializes them to JSON. evaluate(async => { // await some promise }); Is there an equivalent in PuppeteerSharp? Using EvaluateFunctionAsync, the task completes before the promise resolves: await page. The functions you evaluate can return values. evaluate() function. The way to do this is the following: Set up a file with your evaluate function: // evaluate. evaluate() method in Puppeteer takes JavaScript raw function (or string of JavaScript expression). However, passing variables into this function can be tricky. This page is a list of Puppet's built-in functions, with descriptions of what they do and how to use them. How to implement page. evaluate() 10 Typescript extending third party class error: ElementHandle only refers to a type, but is being used as a value here Dec 10, 2024 · Variables in page. evaluate? 2. evaluate(pageFunction[,args]). 11. Jan 13, 2023 · You signed in with another tab or window. Apr 26, 2025 · You can pass arguments to the function executed by page. waitForFunction() method. evaluate? Update for version 1. log(foo); }); } Mar 6, 2024 · How to use Puppeteer’s page. The thing is, that entry page in question doesn’t render a title meta element: Evaluating the title meta element. js environment, you can use the page. Puppeteer - failed to pass variable Apr 6, 2020 · I had the same issue, Puppeteer was crashing a free-tier EC2 instance when I tried to pass ~20MB of data to evaluate(). evaluate and page. $(". Close Browser: Finally, close the browser with browser. evaluate ( '1 + 2' ) ; Nov 13, 2018 · Steps to reproduce Tell us about your environment: Puppeteer version: 1. evaluate cannot directly reference variables from the Node. a. The function to be evaluated in the element's page's context. I am also running with --no-sandbox Just for the sake of code Mar 16, 2021 · page. A call to any function is an expression that resolves to a value. The solution that worked for me was to pass a string to evaluate rather than a function: ¥Although the function is defined in your script context, it actually gets converted to a string by Puppeteer, sent to the target page and evaluated there. Functions are plugins you can call during catalog compilation. close(). evaluate throws TypeError: cannot read innerText of null. evaluate() or page. evaluate() Functions. js version: v11. Jul 23, 2023 · page. – Jul 23, 2018 · The Puppeteer function page. evaluate function as argument. pageFunction <function|string> Function to be evaluated in the page context. My algorithm: Login Open URL Get ul Loop over each li and cli Nov 24, 2019 · I had this exact issue relating to puppeteer and pkg. How can I pass a string in and have that string be available inside of my page. Oct 28, 2019 · A better puppeteer evaluate For that reason I published a little library(my first) that lets me do just that: Aptly named puppeteer-evaluate2, it allows me to write my puppeteer callback code like any other JavaScript code, where closures/imports are available. We can see that the parameters are a spreaded array (args) that is received in last. Because of that, if you want to use an outside variable (a selector, for example) inside the function, you have to pass that variable as an argument to evaluate: Jan 16, 2018 · Puppeteer: pass variable in . XPath is so much more powerful than CSS selectors when it comes to query the DOM. The variable passed doesn't work. evaluate isn't a part of you code, and you can't call a function of your code from it. Mar 9, 2025 · The evaluateHandle method in Puppeteer is a powerful tool for evaluating functions within the context of a page and obtaining a handle to the result. evaluate; Functions bound with page. Although the function is defined in your script context, it actually gets converted to a string by Puppeteer, sent to the target page and evaluated there. evaluate serialize a function and send it to the puppeeter browser. May 7, 2025 · Is it possible to pass a function to Puppeteer's page. evaluate() 中传递变量; Puppeteer 评估函数; 允许将参数化函数作为字符串传递给 page. 0; What steps will reproduce the problem? I am using react-chat-widget and want to run one of it's functions addUserMessage through puppeteer on the accessed page. evaluate() 9. evaluate(`async() => { return Promise. 0, since this is the latest version that is supported by alpine linux. Bug expectation The documentation and certainly many Stack Overflow answers seem to imply that Page. I am using the evaluate function to return links within a drop down in our application. evaluate() method. If the returned value is of a primitive type, it gets automatically converted by Puppeteer to a primitive type in the script context like in the previous example. This applies to all instances of puppeteer functions operating within the context of browser. 1 (18B75) URLs (if applicable): Node. launch evaluate() Evaluates a function in the page context. These two environments are isolated, each with its own rules for running code and exchanging data. The most common one is. height]; }, createHdpiCanvas. Jul 1, 2022 · I am using puppeteer and the script works fine when executing directly with node. Puppeteer: page. Return types . Since you're passing usedLicenses as an argument to evaluate(), you can access it inside the evaluate function directly by referencing it within the function's scope. evaluate() method? How can I dynamically inject functions to evaluate using Puppeteer? Jul 24, 2020 · I am trying to use an XPath and an external variable in Puppeteer's evaluate function, but there is a problem: if I use the evaluate function with passing in the external variable then I can't pass in the XPath, if I remove the XPath everything is fine, but I need to do it with an XPath. element") const element2=await page. Sep 11, 2019 · The issue is that # is a special character in URLs. evaluate() can only transfer serializable values (roughly, the values JSON can handle). Nov 7, 2018 · Is it possible to pass a function to Puppeteer's page. log as a trigger here is a strange choice. open(url, function() { var foo = 42; page. So I am asking it here. evaluae((getContent()) => it does not work. Below is the syntax for using the evaluate function: Sep 8, 2019 · Following the puppeteer's documentation, you can see where we can insert parameters. log(sum); // Outputs: 3 Returning Complex Objects. evaluate ( '(' + myFunction . js script. Jan 3, 2019 · I am not sure if this is an issue with Puppeteer but I looked around and could not find a proper answer to my question. eid fksry arvu uko iqo oztmo ywan litec unydzj sarl