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How to use EvaluateFunctionHandleAsync method of PuppeteerSharp.Frame class

Best Puppeteer-sharp code snippet using PuppeteerSharp.Frame.EvaluateFunctionHandleAsync

Frame.cs

Source:Frame.cs

...207            var context = await GetExecutionContextAsync().ConfigureAwait(false);208            return await context.EvaluateExpressionHandleAsync(script).ConfigureAwait(false);209        }210        /// <summary>211        /// Passes a function to the <see cref="ExecutionContext.EvaluateFunctionAsync(string, object[])"/>, returns a <see cref="Task"/>, then <see cref="ExecutionContext.EvaluateFunctionHandleAsync(string, object[])"/> would wait for the <see cref="Task"/> to resolve and return its value.212        /// </summary>213        /// <example>214        /// <code>215        /// var frame = page.MainFrame;216        /// const handle = Page.MainFrame.EvaluateFunctionHandleAsync("() => Promise.resolve(self)");217        /// return handle; // Handle for the global object.218        /// </code>219        /// <see cref="JSHandle"/> instances can be passed as arguments to the <see cref="ExecutionContext.EvaluateFunctionAsync(string, object[])"/>:220        /// 221        /// const handle = await Page.MainFrame.EvaluateExpressionHandleAsync("document.body");222        /// const resultHandle = await Page.MainFrame.EvaluateFunctionHandleAsync("body => body.innerHTML", handle);223        /// return await resultHandle.JsonValueAsync(); // prints body's innerHTML224        /// </example>225        /// <returns>Resolves to the return value of <paramref name="function"/></returns>226        /// <param name="function">Function to be evaluated in the <see cref="ExecutionContext"/></param>227        /// <param name="args">Arguments to pass to <paramref name="function"/></param>228        public async Task<JSHandle> EvaluateFunctionHandleAsync(string function, params object[] args)229        {230            var context = await GetExecutionContextAsync().ConfigureAwait(false);231            return await context.EvaluateFunctionHandleAsync(function, args).ConfigureAwait(false);232        }233        /// <summary>234        /// Gets the <see cref="ExecutionContext"/> associated with the frame.235        /// </summary>236        /// <returns><see cref="ExecutionContext"/> associated with the frame.</returns>237        public Task<ExecutionContext> GetExecutionContextAsync() => _contextResolveTaskWrapper.Task;238        /// <summary>239        /// Waits for a selector to be added to the DOM240        /// </summary>241        /// <param name="selector">A selector of an element to wait for</param>242        /// <param name="options">Optional waiting parameters</param>243        /// <returns>A task that resolves when element specified by selector string is added to DOM</returns>244        /// <seealso cref="WaitForXPathAsync(string, WaitForSelectorOptions)"/>245        /// <seealso cref="Page.WaitForSelectorAsync(string, WaitForSelectorOptions)"/>246        /// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>247        public Task<ElementHandle> WaitForSelectorAsync(string selector, WaitForSelectorOptions options = null)248            => WaitForSelectorOrXPathAsync(selector, false, options);249        /// <summary>250        /// Waits for a selector to be added to the DOM251        /// </summary>252        /// <param name="xpath">A xpath selector of an element to wait for</param>253        /// <param name="options">Optional waiting parameters</param>254        /// <returns>A task that resolves when element specified by selector string is added to DOM</returns>255        /// <example>256        /// <code>257        /// <![CDATA[258        /// var browser = await Puppeteer.LaunchAsync(new LaunchOptions());259        /// var page = await browser.NewPageAsync();260        /// string currentURL = null;261        /// page.MainFrame262        ///     .WaitForXPathAsync("//img")263        ///     .ContinueWith(_ => Console.WriteLine("First URL with image: " + currentURL));264        /// foreach (var current in new[] { "https://example.com", "https://google.com", "https://bbc.com" })265        /// {266        ///     currentURL = current;267        ///     await page.GoToAsync(currentURL);268        /// }269        /// await browser.CloseAsync();270        /// ]]>271        /// </code>272        /// </example>273        /// <seealso cref="WaitForSelectorAsync(string, WaitForSelectorOptions)"/>274        /// <seealso cref="Page.WaitForXPathAsync(string, WaitForSelectorOptions)"/>275        /// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>276        public Task<ElementHandle> WaitForXPathAsync(string xpath, WaitForSelectorOptions options = null)277            => WaitForSelectorOrXPathAsync(xpath, true, options);278        /// <summary>279        /// Waits for a timeout280        /// </summary>281        /// <param name="milliseconds"></param>282        /// <returns>A task that resolves when after the timeout</returns>283        /// <seealso cref="Page.WaitForTimeoutAsync(int)"/>284        /// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>285        public Task WaitForTimeoutAsync(int milliseconds) => Task.Delay(milliseconds);286        /// <summary>287        /// Waits for a function to be evaluated to a truthy value288        /// </summary>289        /// <param name="script">Function to be evaluated in browser context</param>290        /// <param name="options">Optional waiting parameters</param>291        /// <param name="args">Arguments to pass to <c>script</c></param>292        /// <returns>A task that resolves when the <c>script</c> returns a truthy value</returns>293        /// <seealso cref="Page.WaitForFunctionAsync(string, WaitForFunctionOptions, object[])"/>294        /// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>295        public Task<JSHandle> WaitForFunctionAsync(string script, WaitForFunctionOptions options, params object[] args)296            => new WaitTask(this, script, false, "function", options.Polling, options.PollingInterval, options.Timeout, args).Task;297        /// <summary>298        /// Waits for an expression to be evaluated to a truthy value299        /// </summary>300        /// <param name="script">Expression to be evaluated in browser context</param>301        /// <param name="options">Optional waiting parameters</param>302        /// <returns>A task that resolves when the <c>script</c> returns a truthy value</returns>303        /// <seealso cref="Page.WaitForExpressionAsync(string, WaitForFunctionOptions)"/>304        /// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>305        public Task<JSHandle> WaitForExpressionAsync(string script, WaitForFunctionOptions options)306            => new WaitTask(this, script, true, "function", options.Polling, options.PollingInterval, options.Timeout).Task;307        /// <summary>308        /// Triggers a change and input event once all the provided options have been selected. 309        /// If there's no <![CDATA[<select>]]> element matching selector, the method throws an error.310        /// </summary>311        /// <exception cref="SelectorException">If there's no element matching <paramref name="selector"/></exception>312        /// <param name="selector">A selector to query page for</param>313        /// <param name="values">Values of options to select. If the <![CDATA[<select>]]> has the multiple attribute, 314        /// all values are considered, otherwise only the first one is taken into account.</param>315        /// <returns>Returns an array of option values that have been successfully selected.</returns>316        /// <seealso cref="Page.SelectAsync(string, string[])"/>317        public Task<string[]> SelectAsync(string selector, params string[] values)318            => QuerySelectorAsync(selector).EvaluateFunctionAsync<string[]>(@"(element, values) => {319                if (element.nodeName.toLowerCase() !== 'select')320                    throw new Error('Element is not a <select> element.');321                const options = Array.from(element.options);322                element.value = undefined;323                for (const option of options) {324                    option.selected = values.includes(option.value);325                    if (option.selected && !element.multiple)326                      break;327                }328                element.dispatchEvent(new Event('input', { 'bubbles': true }));329                element.dispatchEvent(new Event('change', { 'bubbles': true }));330                return options.filter(option => option.selected).map(option => option.value);331            }", new[] { values });332        /// <summary>333        /// Queries frame for the selector. If there's no such element within the frame, the method will resolve to <c>null</c>.334        /// </summary>335        /// <param name="selector">Selector to query frame for</param>336        /// <returns>Task which resolves to <see cref="ElementHandle"/> pointing to the frame element</returns>337        /// <seealso cref="Page.QuerySelectorAsync(string)"/>338        public async Task<ElementHandle> QuerySelectorAsync(string selector)339        {340            var document = await GetDocument().ConfigureAwait(false);341            var value = await document.QuerySelectorAsync(selector).ConfigureAwait(false);342            return value;343        }344        /// <summary>345        /// Queries frame for the selector. If no elements match the selector, the return value resolve to <see cref="Array.Empty{T}"/>.346        /// </summary>347        /// <param name="selector">A selector to query frame for</param>348        /// <returns>Task which resolves to ElementHandles pointing to the frame elements</returns>349        /// <seealso cref="Page.QuerySelectorAllAsync(string)"/>350        public async Task<ElementHandle[]> QuerySelectorAllAsync(string selector)351        {352            var document = await GetDocument().ConfigureAwait(false);353            var value = await document.QuerySelectorAllAsync(selector).ConfigureAwait(false);354            return value;355        }356        /// <summary>357        /// Evaluates the XPath expression358        /// </summary>359        /// <param name="expression">Expression to evaluate <see href="https://developer.mozilla.org/en-US/docs/Web/API/Document/evaluate"/></param>360        /// <returns>Task which resolves to an array of <see cref="ElementHandle"/></returns>361        /// <seealso cref="Page.XPathAsync(string)"/>362        public async Task<ElementHandle[]> XPathAsync(string expression)363        {364            var document = await GetDocument().ConfigureAwait(false);365            var value = await document.XPathAsync(expression).ConfigureAwait(false);366            return value;367        }368        /// <summary>369        /// Adds a <c><![CDATA[<link rel="stylesheet">]]></c> tag into the page with the desired url or a <c><![CDATA[<link rel="stylesheet">]]></c> tag with the content370        /// </summary>371        /// <param name="options">add style tag options</param>372        /// <returns>Task which resolves to the added tag when the stylesheet's onload fires or when the CSS content was injected into frame</returns>373        /// <seealso cref="Page.AddStyleTagAsync(AddTagOptions)"/>374        /// <seealso cref="Page.AddStyleTagAsync(string)"/>375        public async Task<ElementHandle> AddStyleTag(AddTagOptions options)376        {377            const string addStyleUrl = @"async function addStyleUrl(url) {378              const link = document.createElement('link');379              link.rel = 'stylesheet';380              link.href = url;381              const promise = new Promise((res, rej) => {382                link.onload = res;383                link.onerror = rej;384              });385              document.head.appendChild(link);386              await promise;387              return link;388            }";389            const string addStyleContent = @"async function addStyleContent(content) {390              const style = document.createElement('style');391              style.type = 'text/css';392              style.appendChild(document.createTextNode(content));393              const promise = new Promise((res, rej) => {394                style.onload = res;395                style.onerror = rej;396              });397              document.head.appendChild(style);398              await promise;399              return style;400            }";401            if (!string.IsNullOrEmpty(options.Url))402            {403                var url = options.Url;404                try405                {406                    var context = await GetExecutionContextAsync().ConfigureAwait(false);407                    return (await context.EvaluateFunctionHandleAsync(addStyleUrl, url).ConfigureAwait(false)) as ElementHandle;408                }409                catch (PuppeteerException)410                {411                    throw new PuppeteerException($"Loading style from {url} failed");412                }413            }414            if (!string.IsNullOrEmpty(options.Path))415            {416                var contents = await AsyncFileHelper.ReadAllText(options.Path).ConfigureAwait(false);417                contents += "//# sourceURL=" + options.Path.Replace("\n", string.Empty);418                var context = await GetExecutionContextAsync().ConfigureAwait(false);419                return (await context.EvaluateFunctionHandleAsync(addStyleContent, contents).ConfigureAwait(false)) as ElementHandle;420            }421            if (!string.IsNullOrEmpty(options.Content))422            {423                var context = await GetExecutionContextAsync().ConfigureAwait(false);424                return (await context.EvaluateFunctionHandleAsync(addStyleContent, options.Content).ConfigureAwait(false)) as ElementHandle;425            }426            throw new ArgumentException("Provide options with a `Url`, `Path` or `Content` property");427        }428        /// <summary>429        /// Adds a <c><![CDATA[<script>]]></c> tag into the page with the desired url or content430        /// </summary>431        /// <param name="options">add script tag options</param>432        /// <returns>Task which resolves to the added tag when the script's onload fires or when the script content was injected into frame</returns>433        /// <seealso cref="Page.AddScriptTagAsync(AddTagOptions)"/>434        /// <seealso cref="Page.AddScriptTagAsync(string)"/>435        public async Task<ElementHandle> AddScriptTag(AddTagOptions options)436        {437            const string addScriptUrl = @"async function addScriptUrl(url, type) {438              const script = document.createElement('script');439              script.src = url;440              if(type)441                script.type = type;442              const promise = new Promise((res, rej) => {443                script.onload = res;444                script.onerror = rej;445              });446              document.head.appendChild(script);447              await promise;448              return script;449            }";450            const string addScriptContent = @"function addScriptContent(content, type = 'text/javascript') {451              const script = document.createElement('script');452              script.type = type;453              script.text = content;454              let error = null;455              script.onerror = e => error = e;456              document.head.appendChild(script);457              if (error)458                throw error;459              return script;460            }";461            async Task<ElementHandle> AddScriptTagPrivate(string script, string urlOrContent, string type)462            {463                var context = await GetExecutionContextAsync().ConfigureAwait(false);464                return (string.IsNullOrEmpty(type)465                        ? await context.EvaluateFunctionHandleAsync(script, urlOrContent).ConfigureAwait(false)466                        : await context.EvaluateFunctionHandleAsync(script, urlOrContent, type).ConfigureAwait(false)) as ElementHandle;467            }468            if (!string.IsNullOrEmpty(options.Url))469            {470                var url = options.Url;471                try472                {473                    return await AddScriptTagPrivate(addScriptUrl, url, options.Type).ConfigureAwait(false);474                }475                catch (PuppeteerException)476                {477                    throw new PuppeteerException($"Loading script from {url} failed");478                }479            }480            if (!string.IsNullOrEmpty(options.Path))...

ElementHandle.cs

Source:ElementHandle.cs

...239        /// <param name="selector">A selector to query element for</param>240        /// <returns>Task which resolves to <see cref="ElementHandle"/> pointing to the frame element</returns>241        public async Task<ElementHandle> QuerySelectorAsync(string selector)242        {243            var handle = await ExecutionContext.EvaluateFunctionHandleAsync(244                "(element, selector) => element.querySelector(selector)",245                this, selector).ConfigureAwait(false);246            if (handle is ElementHandle element)247            {248                return element;249            }250            await handle.DisposeAsync().ConfigureAwait(false);251            return null;252        }253        /// <summary>254        /// Runs <c>element.querySelectorAll</c> within the page. If no elements match the selector, the return value resolve to <see cref="Array.Empty{T}"/>.255        /// </summary>256        /// <param name="selector">A selector to query element for</param>257        /// <returns>Task which resolves to ElementHandles pointing to the frame elements</returns>258        public async Task<ElementHandle[]> QuerySelectorAllAsync(string selector)259        {260            var arrayHandle = await ExecutionContext.EvaluateFunctionHandleAsync(261                "(element, selector) => element.querySelectorAll(selector)",262                this, selector).ConfigureAwait(false);263            var properties = await arrayHandle.GetPropertiesAsync().ConfigureAwait(false);264            await arrayHandle.DisposeAsync().ConfigureAwait(false);265            return properties.Values.OfType<ElementHandle>().ToArray();266        }267        /// <summary>268        /// A utility function to be used with <see cref="Extensions.EvaluateFunctionAsync{T}(Task{JSHandle}, string, object[])"/>269        /// </summary>270        /// <param name="selector">A selector to query element for</param>271        /// <returns>Task which resolves to a <see cref="JSHandle"/> of <c>document.querySelectorAll</c> result</returns>272        public Task<JSHandle> QuerySelectorAllHandleAsync(string selector)273            => ExecutionContext.EvaluateFunctionHandleAsync(274                "(element, selector) => Array.from(element.querySelectorAll(selector))", this, selector);275        /// <summary>276        /// Evaluates the XPath expression relative to the elementHandle. If there's no such element, the method will resolve to <c>null</c>.277        /// </summary>278        /// <param name="expression">Expression to evaluate <see href="https://developer.mozilla.org/en-US/docs/Web/API/Document/evaluate"/></param>279        /// <returns>Task which resolves to an array of <see cref="ElementHandle"/></returns>280        public async Task<ElementHandle[]> XPathAsync(string expression)281        {282            var arrayHandle = await ExecutionContext.EvaluateFunctionHandleAsync(283                @"(element, expression) => {284                    const document = element.ownerDocument || element;285                    const iterator = document.evaluate(expression, element, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE);286                    const array = [];287                    let item;288                    while ((item = iterator.iterateNext()))289                        array.push(item);290                    return array;291                }",292                this, expression293            ).ConfigureAwait(false);294            var properties = await arrayHandle.GetPropertiesAsync().ConfigureAwait(false);295            await arrayHandle.DisposeAsync().ConfigureAwait(false);296            return properties.Values.OfType<ElementHandle>().ToArray();...

EvaluateTests.cs

Source:EvaluateTests.cs

...177        }178        [Fact]179        public async Task ShouldBeAbleToThrowATrickyError()180        {181            var windowHandle = await Page.EvaluateFunctionHandleAsync("() => window");182            PuppeteerException exception = await Assert.ThrowsAsync<MessageException>(() => windowHandle.JsonValueAsync());183            var errorText = exception.Message;184            exception = await Assert.ThrowsAsync<EvaluationFailedException>(() => Page.EvaluateFunctionAsync(@"errorText =>185            {186                throw new Error(errorText);187            }", errorText));188            Assert.Contains(errorText, exception.Message);189        }190        [Theory]191        [InlineData("1 + 5;", 6)] //ShouldAcceptSemiColons192        [InlineData("2 + 5\n// do some math!'", 7)] //ShouldAceptStringComments193        public async Task BasicIntExressionEvaluationTest(string script, object expected)194        {195            var result = await Page.EvaluateExpressionAsync<int>(script);196            Assert.Equal(expected, result);197        }198        [Fact]199        public async Task ShouldAcceptElementHandleAsAnArgument()200        {201            await Page.SetContentAsync("<section>42</section>");202            var element = await Page.QuerySelectorAsync("section");203            var text = await Page.EvaluateFunctionAsync<string>("e => e.textContent", element);204            Assert.Equal("42", text);205        }206        [Fact]207        public async Task ShouldThrowIfUnderlyingElementWasDisposed()208        {209            await Page.SetContentAsync("<section>39</section>");210            var element = await Page.QuerySelectorAsync("section");211            Assert.NotNull(element);212            await element.DisposeAsync();213            var exception = await Assert.ThrowsAsync<EvaluationFailedException>(()214                => Page.EvaluateFunctionAsync<string>("e => e.textContent", element));215            Assert.Contains("JSHandle is disposed", exception.Message);216        }217        [Fact]218        public async Task ShouldThrowIfElementHandlesAreFromOtherFrames()219        {220            await FrameUtils.AttachFrameAsync(Page, "frame1", TestConstants.EmptyPage);221            var bodyHandle = await Page.FirstChildFrame().QuerySelectorAsync("body");222            var exception = await Assert.ThrowsAsync<EvaluationFailedException>(()223                => Page.EvaluateFunctionAsync<string>("body => body.innerHTML", bodyHandle));224            Assert.Contains("JSHandles can be evaluated only in the context they were created", exception.Message);225        }226        [Fact]227        public async Task ShouldSimulateAUserGesture()228            => Assert.True(await Page.EvaluateFunctionAsync<bool>(@"() => {229                document.body.appendChild(document.createTextNode('test'));230                document.execCommand('selectAll');231                return document.execCommand('copy'); 232            }"));233        [Fact]234        public async Task ShouldThrowANiceErrorAfterANavigation()235        {236            var executionContext = await Page.MainFrame.GetExecutionContextAsync();237            await Task.WhenAll(238                Page.WaitForNavigationAsync(),239                executionContext.EvaluateFunctionAsync("() => window.location.reload()")240            );241            var ex = await Assert.ThrowsAsync<EvaluationFailedException>(() =>242            {243                return executionContext.EvaluateFunctionAsync("() => null");244            });245            Assert.Contains("navigation", ex.Message);246        }247        [Fact]248        public async Task ShouldNotThrowAnErrorWhenEvaluationDoesANavigation()249        {250            await Page.GoToAsync(TestConstants.ServerUrl + "/one-style.html");251            var result = await Page.EvaluateFunctionAsync<int[]>(@"() =>252            {253                window.location = '/empty.html';254                return [42];255            }");256            Assert.Equal(new[] { 42 }, result);257        }258        /// <summary>259        /// Original Name "should transfer 100Mb of data from page to node.js"260        /// </summary>261        [Fact]262        public async Task ShouldTransfer100MbOfDataFromPage()263        {264            var a = await Page.EvaluateFunctionAsync<string>("() => Array(100 * 1024 * 1024 + 1).join('a')");265            Assert.Equal(100 * 1024 * 1024, a.Length);266        }267        [Fact]268        public async Task ShouldThrowErrorWithDetailedInformationOnExceptionInsidePromise()269        {270            var exception = await Assert.ThrowsAsync<EvaluationFailedException>(() =>271                Page.EvaluateFunctionAsync(272                    @"() => new Promise(() => {273                        throw new Error('Error in promise');274                    })"));275            Assert.Contains("Error in promise", exception.Message);276        }277        [Fact]278        public async Task ShouldWorkWithDifferentSerializerSettings()279        {280            var result = await Page.EvaluateFunctionAsync<ComplexObjectTestClass>("() => { return { foo: 'bar' }}");281            Assert.Equal("bar", result.Foo);282            result = (await Page.EvaluateFunctionAsync<JToken>("() => { return { Foo: 'bar' }}"))283                .ToObject<ComplexObjectTestClass>(new JsonSerializerSettings());284            Assert.Equal("bar", result.Foo);285            result = await Page.EvaluateExpressionAsync<ComplexObjectTestClass>("var obj = { foo: 'bar' }; obj;");286            Assert.Equal("bar", result.Foo);287            result = (await Page.EvaluateExpressionAsync<JToken>("var obj = { Foo: 'bar' }; obj;"))288                .ToObject<ComplexObjectTestClass>(new JsonSerializerSettings());289            Assert.Equal("bar", result.Foo);290        }291        [Fact]292        public async Task ShouldProperlyIgnoreUndefinedFields()293        {294            var result = await Page.EvaluateFunctionAsync<Dictionary<string, object>>("() => ({a: undefined})");295            Assert.Empty(result);296        }297        [Fact]298        public async Task ShouldProperlySerializeNullFields()299        {300            var result = await Page.EvaluateFunctionAsync<Dictionary<string, object>>("() => ({a: null})");301            Assert.True(result.ContainsKey("a"));302            Assert.Null(result["a"]);303        }304        [Fact]305        public async Task ShouldAcceptObjectHandleAsAnArgument()306        {307            var navigatorHandle = await Page.EvaluateExpressionHandleAsync("navigator");308            var text = await Page.EvaluateFunctionAsync<string>("e => e.userAgent", navigatorHandle);309            Assert.Contains("Mozilla", text);310        }311        [Fact]312        public async Task ShouldAcceptObjectHandleToPrimitiveTypes()313        {314            var aHandle = await Page.EvaluateExpressionHandleAsync("5");315            var isFive = await Page.EvaluateFunctionAsync<bool>("e => Object.is(e, 5)", aHandle);316            Assert.True(isFive);317        }318        [Fact]319        public async Task ShouldWarnOnNestedObjectHandles()320        {321            var handle = await Page.EvaluateFunctionHandleAsync("() => document.body");322            var elementHandle = handle as ElementHandle;323            var exception = await Assert.ThrowsAsync<EvaluationFailedException>(()324                => Page.EvaluateFunctionHandleAsync(325                    "opts => opts.elem.querySelector('p')",326                    new { elem = handle }));327            Assert.Contains("Are you passing a nested JSHandle?", exception.Message);328            //Check with ElementHandle329            exception = await Assert.ThrowsAsync<EvaluationFailedException>(()330                => Page.EvaluateFunctionHandleAsync(331                    "opts => opts.elem.querySelector('p')",332                    new { elem = elementHandle }));333            Assert.Contains("Are you passing a nested JSHandle?", exception.Message);334        }335        [Fact]336        public async Task ShouldWorkWithoutGenerics()337        {338            Assert.NotNull(await Page.EvaluateExpressionAsync("var obj = {}; obj;"));339            Assert.NotNull(await Page.EvaluateExpressionAsync("[]"));340            Assert.NotNull(await Page.EvaluateExpressionAsync("''"));341            var objectPopulated = await Page.EvaluateExpressionAsync("var obj = {a:1}; obj;");342            Assert.NotNull(objectPopulated);343            Assert.Equal(1, objectPopulated["a"]);344            var arrayPopulated = await Page.EvaluateExpressionAsync("[1]");...

DOMWorld.cs

Source:DOMWorld.cs

...60        {61            var context = await GetExecutionContextAsync().ConfigureAwait(false);62            return await context.EvaluateExpressionHandleAsync(script).ConfigureAwait(false);63        }64        internal async Task<JSHandle> EvaluateFunctionHandleAsync(string script, params object[] args)65        {66            var context = await GetExecutionContextAsync().ConfigureAwait(false);67            return await context.EvaluateFunctionHandleAsync(script, args).ConfigureAwait(false);68        }69        internal async Task<T> EvaluateExpressionAsync<T>(string script)70        {71            var context = await GetExecutionContextAsync().ConfigureAwait(false);72            return await context.EvaluateExpressionAsync<T>(script).ConfigureAwait(false);73        }74        internal async Task<JToken> EvaluateExpressionAsync(string script)75        {76            var context = await GetExecutionContextAsync().ConfigureAwait(false);77            return await context.EvaluateExpressionAsync(script).ConfigureAwait(false);78        }79        internal async Task<T> EvaluateFunctionAsync<T>(string script, params object[] args)80        {81            var context = await GetExecutionContextAsync().ConfigureAwait(false);82            return await context.EvaluateFunctionAsync<T>(script, args).ConfigureAwait(false);83        }84        internal async Task<JToken> EvaluateFunctionAsync(string script, params object[] args)85        {86            var context = await GetExecutionContextAsync().ConfigureAwait(false);87            return await context.EvaluateFunctionAsync(script, args).ConfigureAwait(false);88        }89        internal Task<string> GetContentAsync() => EvaluateFunctionAsync<string>(@"() => {90                let retVal = '';91                if (document.doctype)92                    retVal = new XMLSerializer().serializeToString(document.doctype);93                if (document.documentElement)94                    retVal += document.documentElement.outerHTML;95                return retVal;96            }");97        internal async Task SetContentAsync(string html, NavigationOptions options = null)98        {99            var waitUntil = options?.WaitUntil ?? new[] { WaitUntilNavigation.Load };100            var timeout = options?.Timeout ?? _timeoutSettings.NavigationTimeout;101            // We rely upon the fact that document.open() will reset frame lifecycle with "init"102            // lifecycle event. @see https://crrev.com/608658103            await EvaluateFunctionAsync(@"html => {104                document.open();105                document.write(html);106                document.close();107            }", html).ConfigureAwait(false);108            using (var watcher = new LifecycleWatcher(_frameManager, Frame, waitUntil, timeout))109            {110                var watcherTask = await Task.WhenAny(111                    watcher.TimeoutOrTerminationTask,112                    watcher.LifecycleTask).ConfigureAwait(false);113                await watcherTask.ConfigureAwait(false);114            }115        }116        internal async Task<ElementHandle> AddScriptTagAsync(AddTagOptions options)117        {118            const string addScriptUrl = @"async function addScriptUrl(url, type) {119              const script = document.createElement('script');120              script.src = url;121              if(type)122                script.type = type;123              const promise = new Promise((res, rej) => {124                script.onload = res;125                script.onerror = rej;126              });127              document.head.appendChild(script);128              await promise;129              return script;130            }";131            const string addScriptContent = @"function addScriptContent(content, type = 'text/javascript') {132              const script = document.createElement('script');133              script.type = type;134              script.text = content;135              let error = null;136              script.onerror = e => error = e;137              document.head.appendChild(script);138              if (error)139                throw error;140              return script;141            }";142            async Task<ElementHandle> AddScriptTagPrivate(string script, string urlOrContent, string type)143            {144                var context = await GetExecutionContextAsync().ConfigureAwait(false);145                return (string.IsNullOrEmpty(type)146                        ? await context.EvaluateFunctionHandleAsync(script, urlOrContent).ConfigureAwait(false)147                        : await context.EvaluateFunctionHandleAsync(script, urlOrContent, type).ConfigureAwait(false)) as ElementHandle;148            }149            if (!string.IsNullOrEmpty(options.Url))150            {151                var url = options.Url;152                try153                {154                    return await AddScriptTagPrivate(addScriptUrl, url, options.Type).ConfigureAwait(false);155                }156                catch (PuppeteerException)157                {158                    throw new PuppeteerException($"Loading script from {url} failed");159                }160            }161            if (!string.IsNullOrEmpty(options.Path))162            {163                var contents = await AsyncFileHelper.ReadAllText(options.Path).ConfigureAwait(false);164                contents += "//# sourceURL=" + options.Path.Replace("\n", string.Empty);165                return await AddScriptTagPrivate(addScriptContent, contents, options.Type).ConfigureAwait(false);166            }167            if (!string.IsNullOrEmpty(options.Content))168            {169                return await AddScriptTagPrivate(addScriptContent, options.Content, options.Type).ConfigureAwait(false);170            }171            throw new ArgumentException("Provide options with a `Url`, `Path` or `Content` property");172        }173        internal async Task<ElementHandle> AddStyleTagAsync(AddTagOptions options)174        {175            const string addStyleUrl = @"async function addStyleUrl(url) {176              const link = document.createElement('link');177              link.rel = 'stylesheet';178              link.href = url;179              const promise = new Promise((res, rej) => {180                link.onload = res;181                link.onerror = rej;182              });183              document.head.appendChild(link);184              await promise;185              return link;186            }";187            const string addStyleContent = @"async function addStyleContent(content) {188              const style = document.createElement('style');189              style.type = 'text/css';190              style.appendChild(document.createTextNode(content));191              const promise = new Promise((res, rej) => {192                style.onload = res;193                style.onerror = rej;194              });195              document.head.appendChild(style);196              await promise;197              return style;198            }";199            if (!string.IsNullOrEmpty(options.Url))200            {201                var url = options.Url;202                try203                {204                    var context = await GetExecutionContextAsync().ConfigureAwait(false);205                    return (await context.EvaluateFunctionHandleAsync(addStyleUrl, url).ConfigureAwait(false)) as ElementHandle;206                }207                catch (PuppeteerException)208                {209                    throw new PuppeteerException($"Loading style from {url} failed");210                }211            }212            if (!string.IsNullOrEmpty(options.Path))213            {214                var contents = await AsyncFileHelper.ReadAllText(options.Path).ConfigureAwait(false);215                contents += "//# sourceURL=" + options.Path.Replace("\n", string.Empty);216                var context = await GetExecutionContextAsync().ConfigureAwait(false);217                return (await context.EvaluateFunctionHandleAsync(addStyleContent, contents).ConfigureAwait(false)) as ElementHandle;218            }219            if (!string.IsNullOrEmpty(options.Content))220            {221                var context = await GetExecutionContextAsync().ConfigureAwait(false);222                return (await context.EvaluateFunctionHandleAsync(addStyleContent, options.Content).ConfigureAwait(false)) as ElementHandle;223            }224            throw new ArgumentException("Provide options with a `Url`, `Path` or `Content` property");225        }226        internal Task<ElementHandle> WaitForSelectorAsync(string selector, WaitForSelectorOptions options = null)227            => WaitForSelectorOrXPathAsync(selector, false, options);228        internal Task<ElementHandle> WaitForXPathAsync(string xpath, WaitForSelectorOptions options = null)229            => WaitForSelectorOrXPathAsync(xpath, true, options);230        internal Task<JSHandle> WaitForFunctionAsync(string script, WaitForFunctionOptions options, params object[] args)231            => new WaitTask(232                this,233                script,234                false,235                "function",236                options.Polling,...

ExecutionContext.cs

Source:ExecutionContext.cs

...69        /// If the script, returns a Promise, then the method would wait for the promise to resolve and return its value.70        /// <see cref="JSHandle"/> instances can be passed as arguments71        /// </remarks>72        /// <seealso cref="EvaluateExpressionAsync{T}(string)"/>73        /// <seealso cref="EvaluateFunctionHandleAsync(string, object[])"/>74        /// <returns>Task which resolves to script return value</returns>75        public Task<JToken> EvaluateFunctionAsync(string script, params object[] args)76            => EvaluateAsync<JToken>(EvaluateFunctionHandleAsync(script, args));77        /// <summary>78        /// Executes a function in browser context79        /// </summary>80        /// <typeparam name="T">The type to deserialize the result to</typeparam>81        /// <param name="script">Script to be evaluated in browser context</param>82        /// <param name="args">Arguments to pass to script</param>83        /// <remarks>84        /// If the script, returns a Promise, then the method would wait for the promise to resolve and return its value.85        /// <see cref="JSHandle"/> instances can be passed as arguments86        /// </remarks>87        /// <seealso cref="EvaluateExpressionAsync{T}(string)"/>88        /// <seealso cref="EvaluateFunctionHandleAsync(string, object[])"/>89        /// <returns>Task which resolves to script return value</returns>90        public Task<T> EvaluateFunctionAsync<T>(string script, params object[] args)91            => EvaluateAsync<T>(EvaluateFunctionHandleAsync(script, args));92        /// <summary>93        /// The method iterates JavaScript heap and finds all the objects with the given prototype.94        /// </summary>95        /// <returns>A task which resolves to a handle to an array of objects with this prototype.</returns>96        /// <param name="prototypeHandle">A handle to the object prototype.</param>97        public async Task<JSHandle> QueryObjectsAsync(JSHandle prototypeHandle)98        {99            if (prototypeHandle.Disposed)100            {101                throw new PuppeteerException("Prototype JSHandle is disposed!");102            }103            if (!((JObject)prototypeHandle.RemoteObject).TryGetValue(MessageKeys.ObjectId, out var objectId))104            {105                throw new PuppeteerException("Prototype JSHandle must not be referencing primitive value");106            }107            var response = await _client.SendAsync("Runtime.queryObjects", new Dictionary<string, object>108            {109                {"prototypeObjectId", objectId.ToString()}110            }).ConfigureAwait(false);111            return CreateJSHandle(response[MessageKeys.Objects]);112        }113        internal async Task<JSHandle> EvaluateExpressionHandleAsync(string script)114        {115            if (string.IsNullOrEmpty(script))116            {117                return null;118            }119            try120            {121                return await EvaluateHandleAsync("Runtime.evaluate", new Dictionary<string, object>122                {123                    ["expression"] = _sourceUrlRegex.IsMatch(script) ? script : $"{script}\n{EvaluationScriptSuffix}",124                    ["contextId"] = _contextId,125                    ["returnByValue"] = false,126                    ["awaitPromise"] = true,127                    ["userGesture"] = true128                }).ConfigureAwait(false);129            }130            catch (Exception ex)131            {132                throw new EvaluationFailedException(ex.Message, ex);133            }134        }135        internal async Task<JSHandle> EvaluateFunctionHandleAsync(string script, params object[] args)136        {137            if (string.IsNullOrEmpty(script))138            {139                return null;140            }141            try142            {143                return await EvaluateHandleAsync("Runtime.callFunctionOn", new Dictionary<string, object>144                {145                    ["functionDeclaration"] = $"{script}\n{EvaluationScriptSuffix}\n",146                    [MessageKeys.ExecutionContextId] = _contextId,147                    ["arguments"] = args.Select(FormatArgument),148                    ["returnByValue"] = false,149                    ["awaitPromise"] = true,...

PageExtensions.cs

Source:PageExtensions.cs

...17        /// <returns>Task which resolves to <see cref="ElementHandle"/> pointing to the frame element</returns>18        /// <seealso href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp"/>19        public static async Task<ElementHandle> QuerySelectorWithContentAsync(this Page page, string selector, string regex, string flags = "")20        {21            return await page.GuardFromNull().EvaluateFunctionHandleAsync(22                @"(selector, regex, flags) => {23                    var elements = document.querySelectorAll(selector);24                    return Array.prototype.find.call(elements, function(element) {25                        return RegExp(regex, flags).test(element.textContent);26                    });27                }", selector, regex, flags).ConfigureAwait(false) as ElementHandle;28        }29        /// <summary>30        /// The method runs <c>document.querySelectorAll</c> within the page and then tests a <c>RegExp</c> against the elements <c>textContent</c>. All element matches are returned. If no element matches the selector and regular expression, the return value resolve to <see cref="System.Array.Empty{T}"/>.31        /// </summary>32        /// <param name="page">A <see cref="Page"/> to query</param>33        /// <param name="selector">A selector to query page for</param>34        /// <param name="regex">A regular expression to test against <c>element.textContent</c></param>35        /// <param name="flags">A set of flags for the regular expression</param>36        /// <returns>Task which resolves to ElementHandles pointing to the frame elements</returns>37        /// <seealso href="https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/RegExp"/>38        public static async Task<ElementHandle[]> QuerySelectorAllWithContentAsync(this Page page, string selector, string regex, string flags = "")39        {40            var arrayHandle = await page.GuardFromNull().EvaluateFunctionHandleAsync(41                @"(selector, regex, flags) => {42                    var elements = document.querySelectorAll(selector);43                    return Array.prototype.filter.call(elements, function(element) {44                        return RegExp(regex, flags).test(element.textContent);45                    });46                }", selector, regex, flags).ConfigureAwait(false);47            var properties = await arrayHandle.GetPropertiesAsync().ConfigureAwait(false);48            await arrayHandle.DisposeAsync().ConfigureAwait(false);49            return properties.Values.OfType<ElementHandle>().ToArray();50        }51        /// <summary>52        /// Indicates whether the page has the specified content or not.53        /// </summary>54        /// <param name="page">A <see cref="Page"/></param>...

BoxModelTests.cs

Source:BoxModelTests.cs

...27                top: 2px;28              `;");29            // Step 2: Add div and position it absolutely inside frame.30            var frame = Page.FirstChildFrame();31            var divHandle = (ElementHandle)await frame.EvaluateFunctionHandleAsync(@"() => {32              const div = document.createElement('div');33              document.body.appendChild(div);34              div.style = `35                box-sizing: border-box;36                position: absolute;37                border-left: 1px solid black;38                padding-left: 2px;39                margin-left: 3px;40                left: 4px;41                top: 5px;42                width: 6px;43                height: 7px;44              `;45              return div;...

FrameUtils.cs

Source:FrameUtils.cs

...6    public static class FrameUtils7    {8        public static async Task<Frame> AttachFrameAsync(Page page, string frameId, string url)9        {10            var handle = await page.EvaluateFunctionHandleAsync(@" async (frameId, url) => {11              const frame = document.createElement('iframe');12              frame.src = url;13              frame.id = frameId;14              document.body.appendChild(frame);15              await new Promise(x => frame.onload = x);16              return frame17            }", frameId, url) as ElementHandle;18            return await handle.ContentFrameAsync();19        }20        public static async Task DetachFrameAsync(Page page, string frameId)21        {22            await page.EvaluateFunctionAsync(@"function detachFrame(frameId) {23              const frame = document.getElementById(frameId);24              frame.remove();...

EvaluateFunctionHandleAsync

Using AI Code Generation

1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5    {6        static async Task Main(string[] args)7        {8            var browser = await Puppeteer.LaunchAsync(new LaunchOptions9            {10            });11            var page = await browser.NewPageAsync();12            var result = await page.EvaluateFunctionHandleAsync("function() { return 1; }");13            Console.WriteLine(result);14            await browser.CloseAsync();15        }16    }17}18Your name to display (optional):19Your name to display (optional):20using System;21using System.Threading.Tasks;22using PuppeteerSharp;23{24    {25        static async Task Main(string[] args)26        {27            var browser = await Puppeteer.LaunchAsync(new LaunchOptions28            {29            });30            var page = await browser.NewPageAsync();31            var result = await page.EvaluateFunctionHandleAsync("function() { return 1; }");32            Console.WriteLine(result);33            await browser.CloseAsync();34        }35    }36}37Your name to display (optional):

EvaluateFunctionHandleAsync

Using AI Code Generation

1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5    {6        static async Task Main(string[] args)7        {8            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);9            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))10            {11                var page = await browser.NewPageAsync();12                await page.EvaluateFunctionHandleAsync("() => document.querySelector('input').value = 'PuppeteerSharp'");13                Console.ReadLine();14            }15        }16    }17}18using System;19using System.Threading.Tasks;20using PuppeteerSharp;21{22    {23        static async Task Main(string[] args)24        {25            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);26            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))27            {28                var page = await browser.NewPageAsync();29                await page.EvaluateFunctionHandleAsync("() => document.querySelector('input').value = 'PuppeteerSharp'");30                Console.ReadLine();31            }32        }33    }34}35using System;36using System.Threading.Tasks;37using PuppeteerSharp;38{39    {40        static async Task Main(string[] args)41        {42            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);43            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))44            {45                var page = await browser.NewPageAsync();46                var frame = page.MainFrame;47                await frame.EvaluateFunctionHandleAsync("() => document.querySelector('input').value = 'PuppeteerSharp'");48                Console.ReadLine();49            }50        }51    }52}53using System;54using System.Threading.Tasks;55using PuppeteerSharp;56{

EvaluateFunctionHandleAsync

Using AI Code Generation

1using System;2using System.IO;3using System.Threading.Tasks;4using PuppeteerSharp;5{6    {7        static async Task Main(string[] args)8        {9            var option = new LaunchOptions { Headless = true };10            var browser = await Puppeteer.LaunchAsync(option);11            var page = await browser.NewPageAsync();12            await page.EvaluateFunctionHandleAsync("() => document.body.style.backgroundColor = 'red'");13            await page.ScreenshotAsync("1.png");14            Console.WriteLine("Screenshot saved to 1.png");15            await browser.CloseAsync();16        }17    }18}

EvaluateFunctionHandleAsync

Using AI Code Generation

1var puppeteer = require("puppeteer");2var fs = require("fs");3var path = require("path");4var pathToExtension = path.join(__dirname, "extension");5var extensionFiles = fs.readdirSync(pathToExtension);6var extension = {};7extensionFiles.forEach(function (file) {8  var filePath = path.join(pathToExtension, file);9  var stat = fs.statSync(filePath);10  if (stat.isFile()) {11    extension[file] = fs.readFileSync(filePath, "utf8");12  }13});14var browser = await puppeteer.launch({15});16var page = await browser.newPage();17await page.goto(url);18await page.waitFor(5000);19await page.evaluate(() => {20  var element = document.querySelector("#hplogo");21  element.style.border = "10px solid red";22});23var frame = page.mainFrame();24var handle = await frame.evaluateHandle(() => {25  var element = document.querySelector("#hplogo");26  return element;27});28var result = await frame.evaluateHandle(29  (element) => {30    return element.style.border;31  },32);33var border = await result.jsonValue();34console.log(border);35await browser.close();

EvaluateFunctionHandleAsync

Using AI Code Generation

1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5    {6        static void Main(string[] args)7        {8            MainAsync().GetAwaiter().GetResult();9        }10        static async Task MainAsync()11        {12            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))13            {14                var page = await browser.NewPageAsync();15                var title = await page.EvaluateFunctionHandleAsync(@"() => {16                    return document.title;17                }");18                Console.WriteLine(title);19            }20        }21    }22}23using System;24using System.Threading.Tasks;25using PuppeteerSharp;26{27    {28        static void Main(string[] args)29        {30            MainAsync().GetAwaiter().GetResult();31        }32        static async Task MainAsync()33        {34            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = false }))35            {36                var page = await browser.NewPageAsync();37                var title = await page.EvaluateFunctionHandleAsync(@"() => {38                    return document.title;39                }");40                var value = await title.JsonValueAsync();41                Console.WriteLine(value);42            }43        }44    }45}46using System;47using System.Threading.Tasks;48using PuppeteerSharp;49{50    {51        static void Main(string[] args)52        {53            MainAsync().GetAwaiter().GetResult();54        }55        static async Task MainAsync()56        {57            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions

EvaluateFunctionHandleAsync

Using AI Code Generation

1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5    {6        static void Main(string[] args)7        {8            MainAsync().Wait();9        }10        static async Task MainAsync()11        {12            var browser = await Puppeteer.LaunchAsync(new LaunchOptions13            {14            });15            var page = await browser.NewPageAsync();16            var elementHandle = await page.QuerySelectorAsync("input[name=search]");17            var searchValue = await page.EvaluateFunctionHandleAsync<string>(@"(element) => {18                element.value = 'Puppeteer';19                return element.value;20            }", elementHandle);21            Console.WriteLine(searchValue);22            await browser.CloseAsync();23        }24    }25}

EvaluateFunctionHandleAsync

Using AI Code Generation

1using PuppeteerSharp;2{3    {4        static void Main(string[] args)5        {6            EvaluateFunctionHandleAsync().Wait();7        }8        private static async Task EvaluateFunctionHandleAsync()9        {10            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions11            {12                Args = new string[] { "--no-sandbox" }13            }))14            {15                var page = await browser.NewPageAsync();16                await page.SetViewportAsync(new ViewPortOptions { Width = 1366, Height = 768 });17                var functionHandle = await page.EvaluateFunctionHandleAsync("() => { return document.body; }");18                var value = await functionHandle.JsonValueAsync();19                Console.WriteLine(value);20            }21        }22    }23}

EvaluateFunctionHandleAsync

Using AI Code Generation

1using System;2using System.Threading.Tasks;3using PuppeteerSharp;4{5    {6        static async Task Main(string[] args)7        {8            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);9            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true }))10            using (var page = await browser.NewPageAsync())11            {12                var title = await page.EvaluateFunctionHandleAsync("() => document.title");13                Console.WriteLine(await page.EvaluateFunctionAsync<string>("x => x", title));14            }15        }16    }17}18using System;19using System.Threading.Tasks;20using PuppeteerSharp;21{22    {23        static async Task Main(string[] args)24        {25            await new BrowserFetcher().DownloadAsync(BrowserFetcher.DefaultRevision);26            using (var browser = await Puppeteer.LaunchAsync(new LaunchOptions { Headless = true }))27            using (var page = await browser.NewPageAsync())28            {29                var title = await page.EvaluateFunctionHandleAsync("() => document.title");30                var element = await page.EvaluateFunctionHandleAsync("() => document.body");31                Console.WriteLine(await page.EvaluateFunctionAsync<string>("(x, y) => x === y, title, element"));32            }33        }34    }35}

Automation Testing Tutorials

Learn to execute automation testing from scratch with LambdaTest Learning Hub. Right from setting up the prerequisites to run your first automation test, to following best practices and diving deeper into advanced test scenarios. LambdaTest Learning Hubs compile a list of step-by-step guides to help you be proficient with different test automation frameworks i.e. Selenium, Cypress, TestNG etc.