2

我正在将 Python3 应用程序转换为使用 WebKit2 而不是 WebKit(在 Debian Buster 中不再可用)。

在应用程序中,用户可以(取消)选择我从 Python3 应用程序中读取的复选框。在原始代码中,我可以简单地获取 Webview 的 DomDocument 并遍历子对象以返回具有给定名称的对象的值(下面的示例代码)。

在 WebKit2 中,get_dom_document函数不再可用,WebKit2 文档也不清楚如何进行。

有谁知道如何从 WebKit2 Webview 或其他方式获取 DomDocument 按名称遍历所有对象并获取它们的值?

来自 WebKit Webview 的示例代码 DomDocument:

def get_element_values(self, element_name):
    values = []
    doc = self.get_dom_document()
    elements = doc.get_elements_by_name(element_name)
    for i in range(elements.get_length()):
        child = elements.item(i)
        value = child.get_value().strip()
        if not child.get_checked():
            value = ''
        if value:
            values.append(value)
    return values

注意:“self”是 WebKit.Webview。

[编辑]

我一直在试验这个。首先,我尝试通过首先获取 WebPage 对象来获取 DomDocument。我找到了 WebView.get_page_id() 和 WebKit2WebExtension.get_page(page_id) 但不幸的是,这给了我这个错误:AttributeError:'gi.repository.WebKit2WebExtension'对象没有属性'get_page'。

之后我尝试了 JavaScriptCore 并使用 WebView.run_javascript() 和 WebView.run_javascript_finish() 插入 JavaScript。我得到了一个 JavaScriptResult 对象,但是当我尝试使用 .get_value() 获取值时,我收到了这个错误:TypeError:找不到'JavaScriptCore.Value'的外部结构转换器。

这里有一个用户有同样的问题但建议的解决方案对我来说也太复杂了。

这是我用于测试的代码(检查 get_element_values() 和 javascript_finished() 函数):

#! /usr/bin/env python3

# WebKit2 reference: https://webkitgtk.org/reference/webkit2gtk/stable
# Code examples: https://github.com/sidus-dev/poseidon/blob/master/poseidon.py

import gi
gi.require_version('WebKit2', '4.0')
gi.require_version('WebKit2WebExtension', '4.0')
from gi.repository import WebKit2, WebKit2WebExtension, Gtk
from os.path import exists
import webbrowser
import re


class SimpleBrowser(WebKit2.WebView):
    def __init__(self):
        WebKit2.WebView.__init__(self)

        # Get version
        self.webkit_ver = WebKit2.get_major_version(), WebKit2.get_minor_version(), WebKit2.get_micro_version()
        print(("WebKit2 Version: {0}".format('.'.join(map(str, self.webkit_ver)))))

        # Signals
        self.connect('decide-policy', self.on_decide_policy)
        #self.connect("load_changed", self.on_load_changed)
        self.connect("load-failed", self.on_load_failed)
        self.connect('button-press-event', lambda w, e: e.button == 3)

        # Settings
        s = self.get_settings()
        s.set_property('allow_file_access_from_file_urls', True)
        s.set_property('enable-spatial-navigation', False)
        s.set_property('enable_javascript', True)


    def show_html(self, html_or_url):
        if exists(html_or_url):
            matchObj = re.search('^file:\/\/', html_or_url)
            if not matchObj:
                html_or_url = "file://{0}".format(html_or_url)
        matchObj = re.search('^[a-z]+:\/\/', html_or_url)
        if matchObj:
            self.load_uri(html_or_url)
        else:
            self.load_html(html_or_url)
        self.show()

    def get_element_values(self, object, element_name):
        # JavaScript > dead end :(
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-run-javascript
        js = 'var e = document.getElementsByName("' + element_name + '"); var r = []; var c = 0; ' \
             'for (var i = 0; i < e.length; i++) { if (e[i].checked) { r[c] = e[i].value; c++;} }'
        self.run_javascript(js, None, self.javascript_finished, None);
        return

        # DOM > dead end :(
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebPage.html
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-get-page-id
        page_id = self.get_page_id()
        print((page_id))
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebExtension.html#webkit-web-extension-get-page
        # AttributeError: 'gi.repository.WebKit2WebExtension' object has no attribute 'get_page'
        web_page = WebKit2WebExtension.get_page(page_id)
        print((web_page))

    def javascript_finished(self, webview, result, user_data):
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-run-javascript-finish
        js_result = self.run_javascript_finish(result)
        print((">>> js_result = %s" % str(js_result)))
        # TypeError: Couldn't find foreign struct converter for 'JavaScriptCore.Value'
        value = js_result.get_value()
        print((">>> value = %s" % str(value)))

    def on_decide_policy(self, webview, decision, decision_type):
        # User clicked on a <a href link: open uri in new tab or new default webview
        if (decision_type == WebKit2.PolicyDecisionType.NAVIGATION_ACTION):
            action = decision.get_navigation_action()
            action_type = action.get_navigation_type()
            if action_type == WebKit2.NavigationType.LINK_CLICKED:
                decision.ignore()
                uri = action.get_request().get_uri()
                # Open link in default browser
                webbrowser.open_new_tab(uri)
        else:
            if decision is not None:
                decision.use()

    def on_load_changed(webview, event):
        # TODO: get html of loaded page
        if event == WebKit2.LoadEvent.FINISHED:
            resource = webview.get_main_resource()
            resource.get_data()
            html = resource.get_data_finish(None)
            print(html)

    def on_load_failed(webview, event, url, error):
        print("Error loading", url, "-", error)

html = '<html><body style="background-color:#E6E6E6;"><h1>WebKit2 Test</h1>' \
       '<p><a href="https://solydxk.com">link</a></p><form onsubmit="return false;">' \
       '<input type="checkbox" name="chktst" value="checkbox1" checked /> CheckBox 1<br />' \
       '<input type="checkbox" name="chktst" value="checkbox2" /> CheckBox 2<br />' \
       '<button onclick="alert(show_values());">JS Show Values</button>' \
       '</form>' \
       '<script>' \
       'function show_values() {' \
       'var e = document.getElementsByName("chktst"); var r = []; var c = 0;' \
       'for (var i = 0; i < e.length; i++) {' \
       '    if (e[i].checked) { r[c] = e[i].value; c++;}' \
       '}return r;}' \
       '</script>' \
       '</body></html>'


win = Gtk.Window()
win.connect("delete-event", Gtk.main_quit)
win.set_default_size(600,400)

webview = SimpleBrowser()
webview.show_html(html)
box = Gtk.Box.new(Gtk.Orientation.VERTICAL, 0)
button = Gtk.Button(label="Python Show Values")
button.connect("clicked", webview.get_element_values, 'chktst')

win.add(box)
box.pack_start(webview, True, True, 0)
box.pack_start(button, False, False, 1)

win.show_all()

Gtk.main() 

[编辑2]

在 Debian Stretch 中,您需要从 backports 安装软件包:

sudo apt-get install -t stretch-backports gir1.2-javascriptcoregtk-4.0 gir1.2-webkit2-4.0 libjavascriptcoregtk-4.0-18 libwebkit2gtk-4.0-37  libwebkit2gtk-4.0-37-gtk2

现在,WebKit2.JavascriptResult.get_js_value() 将返回一个 JavaScriptCore.Value 对象。如果我找到答案,我将进一步测试并回发答案。

检查此错误报告:https ://bugs.webkit.org/show_bug.cgi?id=136989

4

2 回答 2

0

我发现如果我要返回getElementsByClassName对象本身,则会引发以下错误:

GLib.Error: WebKitJavascriptError: (699)

这只告诉我它失败了。

但是,我可以让 JavaScript 函数返回带有值的字符串或数组,并将其转换为 Python 中的字符串。

不理想,但它对于我需要它做的事情是可行的。

这是示例代码(查看评论以获取更多信息):

#! /usr/bin/env python3

# WebKit2 reference: https://webkitgtk.org/reference/webkit2gtk/stable

import gi
gi.require_version('Gtk', '3.0')
gi.require_version('WebKit2', '4.0')
from gi.repository import Gtk
from gi.repository import WebKit2
from gi.repository import GObject
from os.path import exists
import webbrowser
import re
import sys


class SimpleBrowser(WebKit2.WebView):
    # Create custom signals
    __gsignals__ = {
        "js-finished" : (GObject.SignalFlags.RUN_LAST, GObject.TYPE_NONE, ()),
        "html-response-finished" : (GObject.SignalFlags.RUN_LAST, GObject.TYPE_NONE, ())
    }

    def __init__(self):
        WebKit2.WebView.__init__(self)

        # Get version
        webkit_ver = WebKit2.get_major_version(), WebKit2.get_minor_version(), WebKit2.get_micro_version()
        print(("WebKit2 Version: {0}".format('.'.join(map(str, webkit_ver)))))
        if webkit_ver[0] < 2 or \
           webkit_ver[1] < 22:
               print(("ERROR: upgrade WebKit2 to version 2.22.x or higher"))
               sys.exit()

        # Store JS output
        self.js_value = None
        # Store html response
        self.html_response = None

        # WebKit2 Signals
        self.connect('decide-policy', self.on_decide_policy)
        self.connect("load_changed", self.on_load_changed)
        self.connect("load-failed", self.on_load_failed)
        self.connect('button-press-event', lambda w, e: e.button == 3)

        # Settings
        s = self.get_settings()
        s.set_property('allow_file_access_from_file_urls', True)
        s.set_property('enable-spatial-navigation', False)
        s.set_property('enable_javascript', True)

    def show_html(self, html_or_url):
        if exists(html_or_url):
            matchObj = re.search('^file:\/\/', html_or_url)
            if not matchObj:
                html_or_url = "file://{0}".format(html_or_url)
        matchObj = re.search('^[a-z]+:\/\/', html_or_url)
        if matchObj:
            self.load_uri(html_or_url)
        else:
            self.load_html(html_or_url)
        self.show()

    def js_run(self, function_name, js_return=True):
        # JavaScript
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-run-javascript
        run_js_finish = self._js_finish if js_return else None
        self.run_javascript(function_name, None, run_js_finish, None);

    def _js_finish(self, webview, result, user_data=None):
        # https://webkitgtk.org/reference/webkit2gtk/stable/WebKitWebView.html#webkit-web-view-run-javascript-finish
        js_result = self.run_javascript_finish(result)
        if js_result is not None:
            # https://webkitgtk.org/reference/jsc-glib/stable/JSCValue.html

            # TypeError: Couldn't find foreign struct converter for 'JavaScriptCore.Value':
            # Make sure you have WebKit2 2.22.x or higher installed.
            # For Debian Stretch you need the backports packages:
            # apt install -t stretch-backports gir1.2-javascriptcoregtk-4.0 gir1.2-webkit2-4.0 libjavascriptcoregtk-4.0-18 libwebkit2gtk-4.0-37  libwebkit2gtk-4.0-37-gtk2

            # Couldn't handle anything but string :(
            # If returning the getElementsByClassName object itself: GLib.Error: WebKitJavascriptError:  (699)
            value = js_result.get_js_value()
            self.js_value = value.to_string()
            #print((self.js_value))
            self.emit('js-finished')

    def on_decide_policy(self, webview, decision, decision_type):
        # User clicked on a <a href link: open uri in new tab or new default webview
        if (decision_type == WebKit2.PolicyDecisionType.NAVIGATION_ACTION):
            action = decision.get_navigation_action()
            action_type = action.get_navigation_type()
            if action_type == WebKit2.NavigationType.LINK_CLICKED:
                decision.ignore()
                uri = action.get_request().get_uri()
                # Open link in default browser
                webbrowser.open_new_tab(uri)
        else:
            if decision is not None:
                decision.use()

    def on_load_changed(self, webview, event):
        # Get html of loaded page
        if event == WebKit2.LoadEvent.FINISHED:
            resource = webview.get_main_resource()
            resource.get_data(None, self._get_response_data_finish, None)

    def  _get_response_data_finish(self, resource, result, user_data=None):
        self.html_response = resource.get_data_finish(result)
        self.emit('html-response-finished')

    def on_load_failed(webview, event, url, error):
        print("Error loading", url, "-", error)

html = '<html>' \
       '<script>' \
       'function get_checked_values(class_name) {' \
       'var e = document.getElementsByClassName(class_name); var r = []; var c = 0;' \
       'if (e.length == 0) { e = document.getElementsById(class_name); }' \
       'for (var i = 0; i < e.length; i++) {' \
       '    if (e[i].checked) { r[c] = e[i].value; c++;}' \
       '}return r;}' \
       '</script>' \
       '</head><body style="background-color:#E6E6E6;"><h1>WebKit2 JavaScript Test</h1>' \
       '<p><a href="https://solydxk.com">link</a></p><form onsubmit="return false;">' \
       '<input type="checkbox" class="chktst" value="checkbox1" checked /> CheckBox 1<br />' \
       '<input type="checkbox" class="chktst" value="checkbox2" /> CheckBox 2<br />' \
       '</form></body></html>'

# Create test window
win = Gtk.Window()
webview = SimpleBrowser()
win.set_default_size(600,400)
button = Gtk.Button(label="Python Show Checked Values")
box = Gtk.Box.new(Gtk.Orientation.VERTICAL, 0)
box.pack_start(webview, True, True, 0)
box.pack_start(button, False, False, 1)
win.add(box)

# Functions
def get_element_values(self, element_name):
    webview.js_run('get_checked_values("{0}")'.format(element_name))

def show_js_value(object):
    print((webview.js_value))

def show_html_response(object):
    print((webview.html_response))

# Signals
win.connect("delete-event", Gtk.main_quit)
button.connect("clicked", get_element_values, 'chktst')
webview.connect("js-finished", show_js_value)
#webview.connect("html-response-finished", show_html_response)

# Load html and show window
webview.show_html(html)
win.show_all()

Gtk.main() 
于 2018-10-21T11:35:27.063 回答
0
  self.webView.run_javascript("document.documentElement.outerHTML", None, self.on_file_save_finish, None)

def on_file_save_finish(self, webview, result, user_data=None):
  document_html = self.webView.run_javascript_finish(result).get_js_value().to_string()

这在 KeiEditor.py 中使用

https://github.com/orchardguides/Kei-HTML-Editor

于 2020-01-06T04:28:17.977 回答