cefpython/examples/tutorial.py at master · linesight/cefpython · GitHub

History

202 lines (170 loc) · 7.44 KB

Raw

100

101

102

103

104

105

106

107

108

109

110

111

112

113

114

115

116

117

118

119

120

121

122

123

124

125

126

127

128

129

130

131

132

133

134

135

136

137

138

139

140

141

142

143

144

145

146

147

148

149

150

151

152

153

154

155

156

157

158

159

160

161

162

163

164

165

166

167

168

169

170

171

172

173

174

175

176

177

178

179

180

181

182

183

184

185

186

187

188

189

190

191

192

193

194

195

196

197

198

199

200

201

202

# Tutorial example. Doesn't depend on any third party GUI framework.

# Tested with CEF Python v57.0+

from cefpython3 import cefpython as cef

import base64

import platform

import sys

import threading

from pkg_resources import parse_version

# HTML code. Browser will navigate to a Data uri created

# from this html code.

HTML_code = """

<!DOCTYPE html>

<html>

<head>

body,html { font-family: Arial; font-size: 11pt; }

div.msg { margin: 0.2em; line-height: 1.4em; }

b { background: #ccc; font-weight: bold; font-size: 10pt;

padding: 0.1em 0.2em; }

b.Python { background: #eee; }

i { font-family: Courier new; font-size: 10pt; border: #eee 1px solid;

padding: 0.1em 0.2em; }

</style>

function js_print(lang, event, msg) {

msg = "<b class="+lang+">"+lang+": "+event+":</b> " + msg;

console = document.getElementById("console")

console.innerHTML += "<div class=msg>"+msg+"</div>";

}

function js_callback_1(ret) {

js_print("Javascript", "html_to_data_uri", ret);

}

function js_callback_2(msg, py_callback) {

js_print("Javascript", "js_callback", msg);

py_callback("String sent from Javascript");

}

window.onload = function(){

js_print("Javascript", "window.onload", "Called");

js_print("Javascript", "python_property", python_property);

js_print("Javascript", "navigator.userAgent", navigator.userAgent);

js_print("Javascript", "cefpython_version", cefpython_version.version);

html_to_data_uri("test", js_callback_1);

external.test_multiple_callbacks(js_callback_2);

};

</script>

</head>

<body>

<h1>Tutorial example</h1>

</body>

</html>

"""

def main():

check_versions()

sys.excepthook = cef.ExceptHook # To shutdown all CEF processes on error

# To change user agent use either "product_version"

# or "user_agent" options. Explained in Tutorial in

# "Change user agent string" section.

settings = {

# "product_version": "MyProduct/10.00",

# "user_agent": "MyAgent/20.00 MyProduct/10.00",

}

cef.Initialize(settings=settings)

set_global_handler()

browser = cef.CreateBrowserSync(url=html_to_data_uri(HTML_code),

window_title="Tutorial")

set_client_handlers(browser)

set_javascript_bindings(browser)

cef.MessageLoop()

cef.Shutdown()

def check_versions():

ver = cef.GetVersion()

print("[tutorial.py] CEF Python {ver}".format(ver=ver["version"]))

print("[tutorial.py] Chromium {ver}".format(ver=ver["chrome_version"]))

print("[tutorial.py] CEF {ver}".format(ver=ver["cef_version"]))

print("[tutorial.py] Python {ver} {arch}".format(

ver=platform.python_version(),

arch=platform.architecture()[0]))

assert parse_version(cef.__version__) >= parse_version("57.0"), "CEF Python v57.0+ required to run this"

def html_to_data_uri(html, js_callback=None):

# This function is called in two ways:

# 1. From Python: in this case value is returned

# 2. From Javascript: in this case value cannot be returned because

# inter-process messaging is asynchronous, so must return value

# by calling js_callback.

html = html.encode("utf-8", "replace")

b64 = base64.b64encode(html).decode("utf-8", "replace")

ret = "data:text/html;base64,{data}".format(data=b64)

if js_callback:

js_print(js_callback.GetFrame().GetBrowser(),

"Python", "html_to_data_uri",

"Called from Javascript. Will call Javascript callback now.")

js_callback.Call(ret)

else:

return ret

def set_global_handler():

# A global handler is a special handler for callbacks that

# must be set before Browser is created using

# SetGlobalClientCallback() method.

global_handler = GlobalHandler()

cef.SetGlobalClientCallback("OnAfterCreated",

global_handler.OnAfterCreated)

def set_client_handlers(browser):

client_handlers = [LoadHandler(), DisplayHandler()]

for handler in client_handlers:

browser.SetClientHandler(handler)

def set_javascript_bindings(browser):

external = External(browser)

bindings = cef.JavascriptBindings(

bindToFrames=False, bindToPopups=False)

bindings.SetProperty("python_property", "This property was set in Python")

bindings.SetProperty("cefpython_version", cef.GetVersion())

bindings.SetFunction("html_to_data_uri", html_to_data_uri)

bindings.SetObject("external", external)

browser.SetJavascriptBindings(bindings)

def js_print(browser, lang, event, msg):

# Execute Javascript function "js_print"

browser.ExecuteFunction("js_print", lang, event, msg)

class GlobalHandler(object):

def OnAfterCreated(self, browser, **_):

"""Called after a new browser is created."""

# DOM is not yet loaded. Using js_print at this moment will

# throw an error: "Uncaught ReferenceError: js_print is not defined".

# We make this error on purpose. This error will be intercepted

# in DisplayHandler.OnConsoleMessage.

js_print(browser, "Python", "OnAfterCreated",

"This will probably never display as DOM is not yet loaded")

# Delay print by 0.5 sec, because js_print is not available yet

args = [browser, "Python", "OnAfterCreated",

"(Delayed) Browser id="+str(browser.GetIdentifier())]

threading.Timer(0.5, js_print, args).start()

class LoadHandler(object):

def OnLoadingStateChange(self, browser, is_loading, **_):

"""Called when the loading state has changed."""

if not is_loading:

# Loading is complete. DOM is ready.

js_print(browser, "Python", "OnLoadingStateChange",

"Loading is complete")

class DisplayHandler(object):

def OnConsoleMessage(self, browser, message, **_):

"""Called to display a console message."""

# This will intercept js errors, see comments in OnAfterCreated

if "error" in message.lower() or "uncaught" in message.lower():

# Prevent infinite recurrence in case something went wrong

if "js_print is not defined" in message.lower():

if hasattr(self, "js_print_is_not_defined"):

print("Python: OnConsoleMessage: "

"Intercepted Javascript error: "+message)

return

else:

self.js_print_is_not_defined = True

# Delay print by 0.5 sec, because js_print may not be

# available yet due to DOM not ready.

args = [browser, "Python", "OnConsoleMessage",

"(Delayed) Intercepted Javascript error: <i>{error}</i>"

.format(error=message)]

threading.Timer(0.5, js_print, args).start()

class External(object):

def __init__(self, browser):

self.browser = browser

def test_multiple_callbacks(self, js_callback):

"""Test both javascript and python callbacks."""

print('in test_multiple_callbacks')

js_print(self.browser, "Python", "test_multiple_callbacks",

"Called from Javascript. Will call Javascript callback now.")

def py_callback(msg_from_js):

js_print(self.browser, "Python", "py_callback", msg_from_js)

js_callback.Call("String sent from Python", py_callback)

if __name__ == '__main__':

main()

cefpython/examples/tutorial.py at master · linesight/cefpython · GitHub

Expand file tree

Breadcrumbs

tutorial.py

Latest commit

History

Breadcrumbs

tutorial.py

File metadata and controls