Is there any way to make browser page avoiding redirects in Pyqt5?

Question

I am working with pyqt5. I want user to click the browser embeded on my pyqt5 application to get the XPATH of the element which he/she is clicking on it.

I got the solution how to implement the above idea by someone but the page on the browser gets redirected to another page of the website.

What if I want the user to click the element, but not allowing him to go further by clicking on the buttons and getting away from the original page. In short, I just want to stick on that same page without redirecting to the another one so as to get the XPATH's of the same page only.

Here's the working code as follows suggested by @eyllanesc :

My file

├── main.py
└── xpath_from_element.js

Main.py

import os

from PyQt5 import QtCore, QtWidgets, QtWebEngineWidgets, QtWebChannel

from jinja2 import Template

CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))


class Element(QtCore.QObject):
    def __init__(self, name, parent=None):
        super(Element, self).__init__(parent)
        self._name = name

    @property
    def name(self):
        return self._name

    def script(self):
        return ""


class WebEnginePage(QtWebEngineWidgets.QWebEnginePage):
    def __init__(self, parent=None):
        super(WebEnginePage, self).__init__(parent)
        self.loadFinished.connect(self.onLoadFinished)
        self._objects = []
        self._scripts = []

    def add_object(self, obj):
        self._objects.append(obj)

    @QtCore.pyqtSlot(bool)
    def onLoadFinished(self, ok):
        print("Finished loading: ", ok)
        if ok:
            self.load_qwebchannel()
            self.add_objects()

    def load_qwebchannel(self):
        file = QtCore.QFile(":/qtwebchannel/qwebchannel.js")
        if file.open(QtCore.QIODevice.ReadOnly):
            content = file.readAll()
            file.close()
            self.runJavaScript(content.data().decode())
        if self.webChannel() is None:
            channel = QtWebChannel.QWebChannel(self)
            self.setWebChannel(channel)

    def add_objects(self):
        if self.webChannel() is not None:
            objects = {obj.name: obj for obj in self._objects}
            self.webChannel().registerObjects(objects)
            _script = """
            {% for obj in objects %}
            var {{obj}};
            {% endfor %}
            new QWebChannel(qt.webChannelTransport, function (channel) {
            {% for obj in objects %}
                {{obj}} = channel.objects.{{obj}};
            {% endfor %}
            }); 
            """
            self.runJavaScript(Template(_script).render(objects=objects.keys()))
            for obj in self._objects:
                if isinstance(obj, Element):
                    self.runJavaScript(obj.script())


class Helper(Element):
    xpathClicked = QtCore.pyqtSignal(str)

    def script(self):
        js = ""
        file = QtCore.QFile(os.path.join(CURRENT_DIR, "xpath_from_element.js"))
        if file.open(QtCore.QIODevice.ReadOnly):
            content = file.readAll()
            file.close()
            js = content.data().decode()

        js += """
        document.addEventListener('click', function(e) {
            e = e || window.event;
            var target = e.target || e.srcElement;
            var xpath = Elements.DOMPath.xPath(target, false); 
            {{name}}.receive_xpath(xpath);
        }, false);"""
        return Template(js).render(name=self.name)

    @QtCore.pyqtSlot(str)
    def receive_xpath(self, xpath):
        self.xpathClicked.emit(xpath)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)

    xpath_helper = Helper("xpath_helper")
    xpath_helper.xpathClicked.connect(lambda xpath: print("clicked", xpath))
    view = QtWebEngineWidgets.QWebEngineView()
    page = WebEnginePage()
    page.add_object(xpath_helper)
    view.setPage(page)
    view.load(QtCore.QUrl("https://www.qt.io"))
    view.show()
    sys.exit(app.exec_())

xpath_from_element.js

// Copyright 2018 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

Elements = {};
Elements.DOMPath = {};

/**
 * @param {!Node} node
 * @param {boolean=} optimized
 * @return {string}
 */
Elements.DOMPath.xPath = function (node, optimized) {
    if (node.nodeType === Node.DOCUMENT_NODE) {
        return '/';
    }

    const steps = [];
    let contextNode = node;
    while (contextNode) {
        const step = Elements.DOMPath._xPathValue(contextNode, optimized);
        if (!step) {
            break;
        }  // Error - bail out early.
        steps.push(step);
        if (step.optimized) {
            break;
        }
        contextNode = contextNode.parentNode;
    }

    steps.reverse();
    return (steps.length && steps[0].optimized ? '' : '/') + steps.join('/');
};

/**
 * @param {!Node} node
 * @param {boolean=} optimized
 * @return {?Elements.DOMPath.Step}
 */
Elements.DOMPath._xPathValue = function (node, optimized) {
    let ownValue;
    const ownIndex = Elements.DOMPath._xPathIndex(node);
    if (ownIndex === -1) {
        return null;
    }  // Error.

    switch (node.nodeType) {
        case Node.ELEMENT_NODE:
            if (optimized && node.getAttribute('id')) {
                return new Elements.DOMPath.Step('//*[@id="' + node.getAttribute('id') + '"]', true);
            }
            ownValue = node.localName;
            break;
        case Node.ATTRIBUTE_NODE:
            ownValue = '@' + node.nodeName;
            break;
        case Node.TEXT_NODE:
        case Node.CDATA_SECTION_NODE:
            ownValue = 'text()';
            break;
        case Node.PROCESSING_INSTRUCTION_NODE:
            ownValue = 'processing-instruction()';
            break;
        case Node.COMMENT_NODE:
            ownValue = 'comment()';
            break;
        case Node.DOCUMENT_NODE:
            ownValue = '';
            break;
        default:
            ownValue = '';
            break;
    }

    if (ownIndex > 0) {
        ownValue += '[' + ownIndex + ']';
    }

    return new Elements.DOMPath.Step(ownValue, node.nodeType === Node.DOCUMENT_NODE);
};

/**
 * @param {!Node} node
 * @return {number}
 */
Elements.DOMPath._xPathIndex = function (node) {
    // Returns -1 in case of error, 0 if no siblings matching the same expression,
    // <XPath index among the same expression-matching sibling nodes> otherwise.
    function areNodesSimilar(left, right) {
        if (left === right) {
            return true;
        }

        if (left.nodeType === Node.ELEMENT_NODE && right.nodeType === Node.ELEMENT_NODE) {
            return left.localName === right.localName;
        }

        if (left.nodeType === right.nodeType) {
            return true;
        }

        // XPath treats CDATA as text nodes.
        const leftType = left.nodeType === Node.CDATA_SECTION_NODE ? Node.TEXT_NODE : left.nodeType;
        const rightType = right.nodeType === Node.CDATA_SECTION_NODE ? Node.TEXT_NODE : right.nodeType;
        return leftType === rightType;
    }

    const siblings = node.parentNode ? node.parentNode.children : null;
    if (!siblings) {
        return 0;
    }  // Root node - no siblings.
    let hasSameNamedElements;
    for (let i = 0; i < siblings.length; ++i) {
        if (areNodesSimilar(node, siblings[i]) && siblings[i] !== node) {
            hasSameNamedElements = true;
            break;
        }
    }
    if (!hasSameNamedElements) {
        return 0;
    }
    let ownIndex = 1;  // XPath indices start with 1.
    for (let i = 0; i < siblings.length; ++i) {
        if (areNodesSimilar(node, siblings[i])) {
            if (siblings[i] === node) {
                return ownIndex;
            }
            ++ownIndex;
        }
    }
    return -1;  // An error occurred: |node| not found in parent's children.
};

/**
 * @unrestricted
 */
Elements.DOMPath.Step = class {
    /**
     * @param {string} value
     * @param {boolean} optimized
     */
    constructor(value, optimized) {
        this.value = value;
        this.optimized = optimized || false;
    }

    /**
     * @override
     * @return {string}
     */
    toString() {
        return this.value;
    }
};

Original answered at Is there any way of getting XPATH of the page in Pyqt5 in browser? Any help would be appreciated...

Answer 1

One possible solution is that the event is not transmitted to the element that is clicked using the preventDefault() method:

js += """
document.addEventListener('click', function(e) {
    e = e || window.event;
    
    var target = e.target || e.srcElement;
    var xpath = Elements.DOMPath.xPath(target, false); 
    {{name}}.receive_xpath(xpath);
}, false);"""