puppeteer/lib/ExecutionContext.js
2019-01-11 15:24:43 -08:00

666 lines
20 KiB
JavaScript

/**
* Copyright 2017 Google Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
const {helper, assert, debugError} = require('./helper');
const path = require('path');
const EVALUATION_SCRIPT_URL = '__puppeteer_evaluation_script__';
const SOURCE_URL_REGEX = /^[\040\t]*\/\/[@#] sourceURL=\s*(\S*?)\s*$/m;
function createJSHandle(context, remoteObject) {
const frame = context.frame();
if (remoteObject.subtype === 'node' && frame) {
const frameManager = frame._frameManager;
return new ElementHandle(context, context._client, remoteObject, frameManager.page(), frameManager);
}
return new JSHandle(context, context._client, remoteObject);
}
class ExecutionContext {
/**
* @param {!Puppeteer.CDPSession} client
* @param {!Protocol.Runtime.ExecutionContextDescription} contextPayload
* @param {?Puppeteer.Frame} frame
*/
constructor(client, contextPayload, frame) {
this._client = client;
this._frame = frame;
this._contextId = contextPayload.id;
this._isDefault = contextPayload.auxData ? !!contextPayload.auxData['isDefault'] : false;
}
/**
* @return {?Puppeteer.Frame}
*/
frame() {
return this._frame;
}
/**
* @param {Function|string} pageFunction
* @param {...*} args
* @return {!Promise<(!Object|undefined)>}
*/
async evaluate(pageFunction, ...args) {
const handle = await this.evaluateHandle(pageFunction, ...args);
const result = await handle.jsonValue().catch(error => {
if (error.message.includes('Object reference chain is too long'))
return;
if (error.message.includes('Object couldn\'t be returned by value'))
return;
throw error;
});
await handle.dispose();
return result;
}
/**
* @param {Function|string} pageFunction
* @param {...*} args
* @return {!Promise<!JSHandle>}
*/
async evaluateHandle(pageFunction, ...args) {
const suffix = `//# sourceURL=${EVALUATION_SCRIPT_URL}`;
if (helper.isString(pageFunction)) {
const contextId = this._contextId;
const expression = /** @type {string} */ (pageFunction);
const expressionWithSourceUrl = SOURCE_URL_REGEX.test(expression) ? expression : expression + '\n' + suffix;
const {exceptionDetails, result: remoteObject} = await this._client.send('Runtime.evaluate', {
expression: expressionWithSourceUrl,
contextId,
returnByValue: false,
awaitPromise: true,
userGesture: true
}).catch(rewriteError);
if (exceptionDetails)
throw new Error('Evaluation failed: ' + helper.getExceptionMessage(exceptionDetails));
return createJSHandle(this, remoteObject);
}
if (typeof pageFunction !== 'function')
throw new Error('The following is not a function: ' + pageFunction);
let functionText = pageFunction.toString();
try {
new Function('(' + functionText + ')');
} catch (e1) {
// This means we might have a function shorthand. Try another
// time prefixing 'function '.
if (functionText.startsWith('async '))
functionText = 'async function ' + functionText.substring('async '.length);
else
functionText = 'function ' + functionText;
try {
new Function('(' + functionText + ')');
} catch (e2) {
// We tried hard to serialize, but there's a weird beast here.
throw new Error('Passed function is not well-serializable!');
}
}
const { exceptionDetails, result: remoteObject } = await this._client.send('Runtime.callFunctionOn', {
functionDeclaration: functionText + '\n' + suffix + '\n',
executionContextId: this._contextId,
arguments: args.map(convertArgument.bind(this)),
returnByValue: false,
awaitPromise: true,
userGesture: true
}).catch(rewriteError);
if (exceptionDetails)
throw new Error('Evaluation failed: ' + helper.getExceptionMessage(exceptionDetails));
return createJSHandle(this, remoteObject);
/**
* @param {*} arg
* @return {*}
* @this {ExecutionContext}
*/
function convertArgument(arg) {
if (Object.is(arg, -0))
return { unserializableValue: '-0' };
if (Object.is(arg, Infinity))
return { unserializableValue: 'Infinity' };
if (Object.is(arg, -Infinity))
return { unserializableValue: '-Infinity' };
if (Object.is(arg, NaN))
return { unserializableValue: 'NaN' };
const objectHandle = arg && (arg instanceof JSHandle) ? arg : null;
if (objectHandle) {
if (objectHandle._context !== this)
throw new Error('JSHandles can be evaluated only in the context they were created!');
if (objectHandle._disposed)
throw new Error('JSHandle is disposed!');
if (objectHandle._remoteObject.unserializableValue)
return { unserializableValue: objectHandle._remoteObject.unserializableValue };
if (!objectHandle._remoteObject.objectId)
return { value: objectHandle._remoteObject.value };
return { objectId: objectHandle._remoteObject.objectId };
}
return { value: arg };
}
/**
* @param {!Error} error
* @return {!Protocol.Runtime.evaluateReturnValue}
*/
function rewriteError(error) {
if (error.message.endsWith('Cannot find context with specified id'))
throw new Error('Execution context was destroyed, most likely because of a navigation.');
throw error;
}
}
/**
* @param {!JSHandle} prototypeHandle
* @return {!Promise<!JSHandle>}
*/
async queryObjects(prototypeHandle) {
assert(!prototypeHandle._disposed, 'Prototype JSHandle is disposed!');
assert(prototypeHandle._remoteObject.objectId, 'Prototype JSHandle must not be referencing primitive value');
const response = await this._client.send('Runtime.queryObjects', {
prototypeObjectId: prototypeHandle._remoteObject.objectId
});
return createJSHandle(this, response.objects);
}
}
class JSHandle {
/**
* @param {!ExecutionContext} context
* @param {!Puppeteer.CDPSession} client
* @param {!Protocol.Runtime.RemoteObject} remoteObject
*/
constructor(context, client, remoteObject) {
this._context = context;
this._client = client;
this._remoteObject = remoteObject;
this._disposed = false;
}
/**
* @return {!ExecutionContext}
*/
executionContext() {
return this._context;
}
/**
* @param {string} propertyName
* @return {!Promise<?JSHandle>}
*/
async getProperty(propertyName) {
const objectHandle = await this._context.evaluateHandle((object, propertyName) => {
const result = {__proto__: null};
result[propertyName] = object[propertyName];
return result;
}, this, propertyName);
const properties = await objectHandle.getProperties();
const result = properties.get(propertyName) || null;
await objectHandle.dispose();
return result;
}
/**
* @return {!Promise<!Map<string, !JSHandle>>}
*/
async getProperties() {
const response = await this._client.send('Runtime.getProperties', {
objectId: this._remoteObject.objectId,
ownProperties: true
});
const result = new Map();
for (const property of response.result) {
if (!property.enumerable)
continue;
result.set(property.name, createJSHandle(this._context, property.value));
}
return result;
}
/**
* @return {!Promise<?Object>}
*/
async jsonValue() {
if (this._remoteObject.objectId) {
const response = await this._client.send('Runtime.callFunctionOn', {
functionDeclaration: 'function() { return this; }',
objectId: this._remoteObject.objectId,
returnByValue: true,
awaitPromise: true,
});
return helper.valueFromRemoteObject(response.result);
}
return helper.valueFromRemoteObject(this._remoteObject);
}
/**
* @return {?Puppeteer.ElementHandle}
*/
asElement() {
return null;
}
async dispose() {
if (this._disposed)
return;
this._disposed = true;
await helper.releaseObject(this._client, this._remoteObject);
}
/**
* @override
* @return {string}
*/
toString() {
if (this._remoteObject.objectId) {
const type = this._remoteObject.subtype || this._remoteObject.type;
return 'JSHandle@' + type;
}
return 'JSHandle:' + helper.valueFromRemoteObject(this._remoteObject);
}
}
class ElementHandle extends JSHandle {
/**
* @param {!Puppeteer.ExecutionContext} context
* @param {!Puppeteer.CDPSession} client
* @param {!Protocol.Runtime.RemoteObject} remoteObject
* @param {!Puppeteer.Page} page
* @param {!Puppeteer.FrameManager} frameManager
*/
constructor(context, client, remoteObject, page, frameManager) {
super(context, client, remoteObject);
this._client = client;
this._remoteObject = remoteObject;
this._page = page;
this._frameManager = frameManager;
this._disposed = false;
}
/**
* @override
* @return {?ElementHandle}
*/
asElement() {
return this;
}
/**
* @return {!Promise<?Puppeteer.Frame>}
*/
async contentFrame() {
const nodeInfo = await this._client.send('DOM.describeNode', {
objectId: this._remoteObject.objectId
});
if (typeof nodeInfo.node.frameId !== 'string')
return null;
return this._frameManager.frame(nodeInfo.node.frameId);
}
async _scrollIntoViewIfNeeded() {
const error = await this.executionContext().evaluate(async(element, pageJavascriptEnabled) => {
if (!element.isConnected)
return 'Node is detached from document';
if (element.nodeType !== Node.ELEMENT_NODE)
return 'Node is not of type HTMLElement';
// force-scroll if page's javascript is disabled.
if (!pageJavascriptEnabled) {
element.scrollIntoView({block: 'center', inline: 'center', behavior: 'instant'});
return false;
}
const visibleRatio = await new Promise(resolve => {
const observer = new IntersectionObserver(entries => {
resolve(entries[0].intersectionRatio);
observer.disconnect();
});
observer.observe(element);
});
if (visibleRatio !== 1.0)
element.scrollIntoView({block: 'center', inline: 'center', behavior: 'instant'});
return false;
}, this, this._page._javascriptEnabled);
if (error)
throw new Error(error);
}
/**
* @return {!Promise<!{x: number, y: number}>}
*/
async _clickablePoint() {
const result = await this._client.send('DOM.getContentQuads', {
objectId: this._remoteObject.objectId
}).catch(debugError);
if (!result || !result.quads.length)
throw new Error('Node is either not visible or not an HTMLElement');
// Filter out quads that have too small area to click into.
const quads = result.quads.map(quad => this._fromProtocolQuad(quad)).filter(quad => computeQuadArea(quad) > 1);
if (!quads.length)
throw new Error('Node is either not visible or not an HTMLElement');
// Return the middle point of the first quad.
const quad = quads[0];
let x = 0;
let y = 0;
for (const point of quad) {
x += point.x;
y += point.y;
}
return {
x: x / 4,
y: y / 4
};
}
/**
* @return {!Promise<void|Protocol.DOM.getBoxModelReturnValue>}
*/
_getBoxModel() {
return this._client.send('DOM.getBoxModel', {
objectId: this._remoteObject.objectId
}).catch(error => debugError(error));
}
/**
* @param {!Array<number>} quad
* @return {!Array<{x: number, y: number}>}
*/
_fromProtocolQuad(quad) {
return [
{x: quad[0], y: quad[1]},
{x: quad[2], y: quad[3]},
{x: quad[4], y: quad[5]},
{x: quad[6], y: quad[7]}
];
}
async hover() {
await this._scrollIntoViewIfNeeded();
const {x, y} = await this._clickablePoint();
await this._page.mouse.move(x, y);
}
/**
* @param {!{delay?: number, button?: "left"|"right"|"middle", clickCount?: number}=} options
*/
async click(options) {
await this._scrollIntoViewIfNeeded();
const {x, y} = await this._clickablePoint();
await this._page.mouse.click(x, y, options);
}
/**
* @param {!Array<string>} filePaths
*/
async uploadFile(...filePaths) {
const files = filePaths.map(filePath => path.resolve(filePath));
const objectId = this._remoteObject.objectId;
await this._client.send('DOM.setFileInputFiles', { objectId, files });
}
async tap() {
await this._scrollIntoViewIfNeeded();
const {x, y} = await this._clickablePoint();
await this._page.touchscreen.tap(x, y);
}
async focus() {
await this.executionContext().evaluate(element => element.focus(), this);
}
/**
* @param {string} text
* @param {{delay: (number|undefined)}=} options
*/
async type(text, options) {
await this.focus();
await this._page.keyboard.type(text, options);
}
/**
* @param {string} key
* @param {!{delay?: number, text?: string}=} options
*/
async press(key, options) {
await this.focus();
await this._page.keyboard.press(key, options);
}
/**
* @return {!Promise<?{x: number, y: number, width: number, height: number}>}
*/
async boundingBox() {
const result = await this._getBoxModel();
if (!result)
return null;
const quad = result.model.border;
const x = Math.min(quad[0], quad[2], quad[4], quad[6]);
const y = Math.min(quad[1], quad[3], quad[5], quad[7]);
const width = Math.max(quad[0], quad[2], quad[4], quad[6]) - x;
const height = Math.max(quad[1], quad[3], quad[5], quad[7]) - y;
return {x, y, width, height};
}
/**
* @return {!Promise<?BoxModel>}
*/
async boxModel() {
const result = await this._getBoxModel();
if (!result)
return null;
const {content, padding, border, margin, width, height} = result.model;
return {
content: this._fromProtocolQuad(content),
padding: this._fromProtocolQuad(padding),
border: this._fromProtocolQuad(border),
margin: this._fromProtocolQuad(margin),
width,
height
};
}
/**
*
* @param {!Object=} options
* @returns {!Promise<string|!Buffer>}
*/
async screenshot(options = {}) {
let needsViewportReset = false;
let boundingBox = await this.boundingBox();
assert(boundingBox, 'Node is either not visible or not an HTMLElement');
const viewport = this._page.viewport();
if (viewport && (boundingBox.width > viewport.width || boundingBox.height > viewport.height)) {
const newViewport = {
width: Math.max(viewport.width, Math.ceil(boundingBox.width)),
height: Math.max(viewport.height, Math.ceil(boundingBox.height)),
};
await this._page.setViewport(Object.assign({}, viewport, newViewport));
needsViewportReset = true;
}
await this._scrollIntoViewIfNeeded();
boundingBox = await this.boundingBox();
assert(boundingBox, 'Node is either not visible or not an HTMLElement');
assert(boundingBox.width !== 0, 'Node has 0 width.');
assert(boundingBox.height !== 0, 'Node has 0 height.');
const { layoutViewport: { pageX, pageY } } = await this._client.send('Page.getLayoutMetrics');
const clip = Object.assign({}, boundingBox);
clip.x += pageX;
clip.y += pageY;
const imageData = await this._page.screenshot(Object.assign({}, {
clip
}, options));
if (needsViewportReset)
await this._page.setViewport(viewport);
return imageData;
}
/**
* @param {string} selector
* @return {!Promise<?ElementHandle>}
*/
async $(selector) {
const handle = await this.executionContext().evaluateHandle(
(element, selector) => element.querySelector(selector),
this, selector
);
const element = handle.asElement();
if (element)
return element;
await handle.dispose();
return null;
}
/**
* @param {string} selector
* @return {!Promise<!Array<!ElementHandle>>}
*/
async $$(selector) {
const arrayHandle = await this.executionContext().evaluateHandle(
(element, selector) => element.querySelectorAll(selector),
this, selector
);
const properties = await arrayHandle.getProperties();
await arrayHandle.dispose();
const result = [];
for (const property of properties.values()) {
const elementHandle = property.asElement();
if (elementHandle)
result.push(elementHandle);
}
return result;
}
/**
* @param {string} selector
* @param {Function|String} pageFunction
* @param {!Array<*>} args
* @return {!Promise<(!Object|undefined)>}
*/
async $eval(selector, pageFunction, ...args) {
const elementHandle = await this.$(selector);
if (!elementHandle)
throw new Error(`Error: failed to find element matching selector "${selector}"`);
const result = await this.executionContext().evaluate(pageFunction, elementHandle, ...args);
await elementHandle.dispose();
return result;
}
/**
* @param {string} selector
* @param {Function|String} pageFunction
* @param {!Array<*>} args
* @return {!Promise<(!Object|undefined)>}
*/
async $$eval(selector, pageFunction, ...args) {
const arrayHandle = await this.executionContext().evaluateHandle(
(element, selector) => Array.from(element.querySelectorAll(selector)),
this, selector
);
const result = await this.executionContext().evaluate(pageFunction, arrayHandle, ...args);
await arrayHandle.dispose();
return result;
}
/**
* @param {string} expression
* @return {!Promise<!Array<!ElementHandle>>}
*/
async $x(expression) {
const arrayHandle = await this.executionContext().evaluateHandle(
(element, expression) => {
const document = element.ownerDocument || element;
const iterator = document.evaluate(expression, element, null, XPathResult.ORDERED_NODE_ITERATOR_TYPE);
const array = [];
let item;
while ((item = iterator.iterateNext()))
array.push(item);
return array;
},
this, expression
);
const properties = await arrayHandle.getProperties();
await arrayHandle.dispose();
const result = [];
for (const property of properties.values()) {
const elementHandle = property.asElement();
if (elementHandle)
result.push(elementHandle);
}
return result;
}
/**
* @returns {!Promise<boolean>}
*/
isIntersectingViewport() {
return this.executionContext().evaluate(async element => {
const visibleRatio = await new Promise(resolve => {
const observer = new IntersectionObserver(entries => {
resolve(entries[0].intersectionRatio);
observer.disconnect();
});
observer.observe(element);
});
return visibleRatio > 0;
}, this);
}
}
function computeQuadArea(quad) {
// Compute sum of all directed areas of adjacent triangles
// https://en.wikipedia.org/wiki/Polygon#Simple_polygons
let area = 0;
for (let i = 0; i < quad.length; ++i) {
const p1 = quad[i];
const p2 = quad[(i + 1) % quad.length];
area += (p1.x * p2.y - p2.x * p1.y) / 2;
}
return Math.abs(area);
}
/**
* @typedef {Object} BoxModel
* @property {!Array<!{x: number, y: number}>} content
* @property {!Array<!{x: number, y: number}>} padding
* @property {!Array<!{x: number, y: number}>} border
* @property {!Array<!{x: number, y: number}>} margin
* @property {number} width
* @property {number} height
*/
helper.tracePublicAPI(ElementHandle);
helper.tracePublicAPI(JSHandle);
helper.tracePublicAPI(ExecutionContext);
module.exports = {ExecutionContext, JSHandle, ElementHandle, createJSHandle, EVALUATION_SCRIPT_URL};