/// <summary>
/// Waits for a selector to be added to the DOM
/// </summary>
/// <param name="xpath">A xpath selector of an element to wait for</param>
/// <param name="options">Optional waiting parameters</param>
/// <returns>A task which resolves when element specified by xpath string is added to DOM.
/// Resolves to `null` if waiting for `hidden: true` and xpath is not found in DOM.</returns>
/// <example>
/// <code>
/// <![CDATA[
/// var browser = await Puppeteer.LaunchAsync(new LaunchOptions());
/// var page = await browser.NewPageAsync();
/// string currentURL = null;
/// page.MainFrame
/// .WaitForXPathAsync("//img")
/// .ContinueWith(_ => Console.WriteLine("First URL with image: " + currentURL));
/// foreach (var current in new[] { "https://example.com", "https://google.com", "https://bbc.com" })
/// {
/// currentURL = current;
/// await page.GoToAsync(currentURL);
/// }
/// await browser.CloseAsync();
/// ]]>
/// </code>
/// </example>
/// <seealso cref="WaitForSelectorAsync(string, WaitForSelectorOptions)"/>
/// <seealso cref="Page.WaitForXPathAsync(string, WaitForSelectorOptions)"/>
/// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>
public async Task <ElementHandle> WaitForXPathAsync(string xpath, WaitForSelectorOptions options = null)
{
var handle = await SecondaryWorld.WaitForXPathAsync(xpath, options).ConfigureAwait(false);
if (handle == null)
{
return(null);
}
var mainExecutionContext = await MainWorld.GetExecutionContextAsync().ConfigureAwait(false);
var result = await mainExecutionContext.AdoptElementHandleASync(handle).ConfigureAwait(false);
await handle.DisposeAsync().ConfigureAwait(false);
return(result);
}
private async Task <ElementHandle> WaitForSelectorOrXPathAsync(string selectorOrXPath, bool isXPath, WaitForSelectorOptions options = null)
{
options = options ?? new WaitForSelectorOptions();
const string predicate = @"
function predicate(selectorOrXPath, isXPath, waitForVisible, waitForHidden) {
const node = isXPath
? document.evaluate(selectorOrXPath, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue
: document.querySelector(selectorOrXPath);
if (!node)
return waitForHidden;
if (!waitForVisible && !waitForHidden)
return node;
const element = node.nodeType === Node.TEXT_NODE ? node.parentElement : node;
const style = window.getComputedStyle(element);
const isVisible = style && style.visibility !== 'hidden' && hasVisibleBoundingBox();
const success = (waitForVisible === isVisible || waitForHidden === !isVisible);
return success ? node : null;
function hasVisibleBoundingBox() {
const rect = element.getBoundingClientRect();
return !!(rect.top || rect.bottom || rect.width || rect.height);
}
}";
var polling = options.Visible || options.Hidden ? WaitForFunctionPollingOption.Raf : WaitForFunctionPollingOption.Mutation;
var handle = await new WaitTask(
this,
predicate,
false,
$"{(isXPath ? "XPath" : "selector")} '{selectorOrXPath}'{(options.Hidden ? " to be hidden" : "")}",
polling,
null,
options.Timeout,
new object[]
{
selectorOrXPath,
isXPath,
options.Visible,
options.Hidden
}).Task.ConfigureAwait(false);
if (!(handle is ElementHandle elementHandle))
{
await handle?.DisposeAsync();
return(null);
}
return(elementHandle);
}
internal Task <ElementHandle> WaitForXPathAsync(string xpath, WaitForSelectorOptions options = null) => WaitForSelectorOrXPathAsync(xpath, true, options);
internal Task <ElementHandle> WaitForSelectorAsync(string selector, WaitForSelectorOptions options = null) => WaitForSelectorOrXPathAsync(selector, false, options);
/// <summary>
/// Waits for a selector to be added to the DOM
/// </summary>
/// <param name="xpath">A xpath selector of an element to wait for</param>
/// <param name="options">Optional waiting parameters</param>
/// <returns>A task that resolves when element specified by selector string is added to DOM</returns>
/// <example>
/// <code>
/// <![CDATA[
/// var browser = await Puppeteer.LaunchAsync(new LaunchOptions());
/// var page = await browser.NewPageAsync();
/// string currentURL = null;
/// page.MainFrame
/// .WaitForXPathAsync("//img")
/// .ContinueWith(_ => Console.WriteLine("First URL with image: " + currentURL));
/// foreach (var current in new[] { "https://example.com", "https://google.com", "https://bbc.com" })
/// {
/// currentURL = current;
/// await page.GoToAsync(currentURL);
/// }
/// await browser.CloseAsync();
/// ]]>
/// </code>
/// </example>
/// <seealso cref="WaitForSelectorAsync(string, WaitForSelectorOptions)"/>
/// <seealso cref="Page.WaitForXPathAsync(string, WaitForSelectorOptions)"/>
/// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception>
public Task <ElementHandle> WaitForXPathAsync(string xpath, WaitForSelectorOptions options = null)
=> _mainWorld.WaitForXPathAsync(xpath, options);
/// <summary> /// Waits for a selector to be added to the DOM /// </summary> /// <param name="selector">A selector of an element to wait for</param> /// <param name="options">Optional waiting parameters</param> /// <returns>A task that resolves when element specified by selector string is added to DOM</returns> /// <seealso cref="WaitForXPathAsync(string, WaitForSelectorOptions)"/> /// <seealso cref="Page.WaitForSelectorAsync(string, WaitForSelectorOptions)"/> /// <exception cref="WaitTaskTimeoutException">If timeout occurred.</exception> public Task <ElementHandle> WaitForSelectorAsync(string selector, WaitForSelectorOptions options = null) => _mainWorld.WaitForSelectorAsync(selector, options);
internal async Task <ElementHandle> WaitForSelectorOrXPathAsync(string selectorOrXPath, bool isXPath, WaitForSelectorOptions options = null)
{
options = options ?? new WaitForSelectorOptions();
const string predicate = @"
function predicate(selectorOrXPath, isXPath, waitForVisible, waitForHidden) {
const node = isXPath
? document.evaluate(selectorOrXPath, document, null, XPathResult.FIRST_ORDERED_NODE_TYPE, null).singleNodeValue
: document.querySelector(selectorOrXPath);
if (!node)
return waitForHidden;
if (!waitForVisible && !waitForHidden)
return node;
const element = node.nodeType === Node.TEXT_NODE ? node.parentElement : node;
const style = window.getComputedStyle(element);
const isVisible = style && style.visibility !== 'hidden' && hasVisibleBoundingBox();
const success = (waitForVisible === isVisible || waitForHidden === !isVisible);
return success ? node : null;
function hasVisibleBoundingBox() {
const rect = element.getBoundingClientRect();
return !!(rect.top || rect.bottom || rect.width || rect.height);
}
}";
var polling = options.Visible || options.Hidden ? WaitForFunctionPollingOption.Raf : WaitForFunctionPollingOption.Mutation;
var handle = await WaitForFunctionAsync(predicate, new WaitForFunctionOptions
{
Timeout = options.Timeout,
Polling = polling
}, selectorOrXPath, isXPath, options.Visible, options.Hidden);
return(handle as ElementHandle);
}
