webdriver协议
何为协议？协议就是客户端和服务器规定好的通信方式。
web driver协议规定了某一个操作（比如find_element_by_id），客户端需要向服务器的哪个路由（其实是通过command来定义的接口地址）接口发送怎样的数据格式以及响应的数据。
协议是抽象类，只规定了有哪些操作和怎样的数据格式，没有具体的实现，具体的实现是由不同的服务器来实现的，比如浏览器驱动、appium服务器，相同的操作对不同的服务器来说调用的接口和传递的参数是相同的，因为这是协议规定的；然而具体的实现是由服务器特定的功能决定的，浏览器驱动是用来操作浏览器的，appium是用来操作手机设备的，具体实现肯定是不同。
appium
appium扩展了selenium，它可以用selenium所有的接口，因为appium服务器也具体实现了其功能，所以可以兼容使用（服务器接口和接收的参数由协议规定）。
selenium/appium怎么向服务器发送请求
这一切都发动自selenium webdriver类中的execute这个方法
def execute(self, driver_command, params=None):
"""
Sends a command to be executed by a command.CommandExecutor.
:Args:
- driver_command: The name of the command to execute as a string.
- params: A dictionary of named parameters to send with the command.
:Returns:
The command's JSON response loaded into a dictionary object.
"""
if self.session_id is not None:
if not params:
params = {'sessionId': self.session_id}
elif 'sessionId' not in params:
params['sessionId'] = self.session_id
params = self._wrap_value(params)
response = self.command_executor.execute(driver_command, params)
if response:
self.error_handler.check_response(response)
response['value'] = self._unwrap_value(
response.get('value', None))
return response
# If the server doesn't send a response, assume the command was
# a success
return {'success': 0, 'value': None, 'sessionId': self.session_id}其中调用了command_executor.execute方法
def execute(self, command, params):
"""
Send a command to the remote server.
Any path subtitutions required for the URL mapped to the command should be
included in the command parameters.
:Args:
- command - A string specifying the command to execute.
- params - A dictionary of named parameters to send with the command as
its JSON payload.
"""
command_info = self._commands[command]
assert command_info is not None, 'Unrecognised command %s' % command
path = string.Template(command_info[1]).substitute(params)
if hasattr(self, 'w3c') and self.w3c and isinstance(params, dict) and 'sessionId' in params:
del params['sessionId']
data = utils.dump_json(params)
url = '%s%s' % (self._url, path)
return self._request(command_info[0], url, body=data) def _request(self, method, url, body=None):
"""
Send an HTTP request to the remote server.
:Args:
- method - A string for the HTTP method to send the request with.
- url - A string for the URL to send the request to.
- body - A string for request body. Ignored unless method is POST or PUT.
:Returns:
A dictionary with the server's parsed JSON response.
"""
LOGGER.debug('%s %s %s' % (method, url, body))
parsed_url = parse.urlparse(url)
headers = self.get_remote_connection_headers(parsed_url, self.keep_alive)
resp = None
if body and method != 'POST' and method != 'PUT':
body = None
if self.keep_alive:
resp = self._conn.request(method, url, body=body, headers=headers)
statuscode = resp.status
else:
http = urllib3.PoolManager(timeout=self._timeout)
resp = http.request(method, url, body=body, headers=headers)
statuscode = resp.status
if not hasattr(resp, 'getheader'):
if hasattr(resp.headers, 'getheader'):
resp.getheader = lambda x: resp.headers.getheader(x)
elif hasattr(resp.headers, 'get'):
resp.getheader = lambda x: resp.headers.get(x)
data = resp.data.decode('UTF-8')
try:
if 300 <= statuscode < 304:
return self._request('GET', resp.getheader('location'))
if 399 < statuscode <= 500:
return {'status': statuscode, 'value': data}
content_type = []
if resp.getheader('Content-Type') is not None:
content_type = resp.getheader('Content-Type').split(';')
if not any([x.startswith('image/png') for x in content_type]):
try:
data = utils.load_json(data.strip())
except ValueError:
if 199 < statuscode < 300:
status = ErrorCode.SUCCESS
else:
status = ErrorCode.UNKNOWN_ERROR
return {'status': status, 'value': data.strip()}
# Some of the drivers incorrectly return a response
# with no 'value' field when they should return null.
if 'value' not in data:
data['value'] = None
return data
else:
data = {'status': 0, 'value': data}
return data
finally:
LOGGER.debug("Finished Request")
resp.close()最终发送请求的是_request这个方法。
在selenium webdriver中的execute中最后用_unwrap_value包装了下返回的响应，放在了response['value']中。
看看服务器路由接口的定义
self._commands = {
Command.STATUS: ('GET', '/status'),
Command.NEW_SESSION: ('POST', '/session'),
Command.GET_ALL_SESSIONS: ('GET', '/sessions'),
Command.QUIT: ('DELETE', '/session/$sessionId'),
Command.GET_CURRENT_WINDOW_HANDLE:
('GET', '/session/$sessionId/window_handle'),
Command.W3C_GET_CURRENT_WINDOW_HANDLE:
('GET', '/session/$sessionId/window'),
Command.GET_WINDOW_HANDLES:
('GET', '/session/$sessionId/window_handles'),
Command.W3C_GET_WINDOW_HANDLES:
('GET', '/session/$sessionId/window/handles'),
Command.GET: ('POST', '/session/$sessionId/url'),
Command.GO_FORWARD: ('POST', '/session/$sessionId/forward'),
Command.GO_BACK: ('POST', '/session/$sessionId/back'),
Command.REFRESH: ('POST', '/session/$sessionId/refresh'),
Command.EXECUTE_SCRIPT: ('POST', '/session/$sessionId/execute'),
Command.W3C_EXECUTE_SCRIPT:
('POST', '/session/$sessionId/execute/sync'),
Command.W3C_EXECUTE_SCRIPT_ASYNC:
('POST', '/session/$sessionId/execute/async'),
Command.GET_CURRENT_URL: ('GET', '/session/$sessionId/url'),
Command.GET_TITLE: ('GET', '/session/$sessionId/title'),
Command.GET_PAGE_SOURCE: ('GET', '/session/$sessionId/source'),
Command.SCREENSHOT: ('GET', '/session/$sessionId/screenshot'),
Command.ELEMENT_SCREENSHOT: ('GET', '/session/$sessionId/element/$id/screenshot'),
Command.FIND_ELEMENT: ('POST', '/session/$sessionId/element'),
Command.FIND_ELEMENTS: ('POST', '/session/$sessionId/elements'),
Command.W3C_GET_ACTIVE_ELEMENT: ('GET', '/session/$sessionId/element/active'),
Command.GET_ACTIVE_ELEMENT:
('POST', '/session/$sessionId/element/active'),
Command.FIND_CHILD_ELEMENT:
('POST', '/session/$sessionId/element/$id/element'),
Command.FIND_CHILD_ELEMENTS:
('POST', '/session/$sessionId/element/$id/elements'),
Command.CLICK_ELEMENT: ('POST', '/session/$sessionId/element/$id/click'),
Command.CLEAR_ELEMENT: ('POST', '/session/$sessionId/element/$id/clear'),
Command.SUBMIT_ELEMENT: ('POST', '/session/$sessionId/element/$id/submit'),
Command.GET_ELEMENT_TEXT: ('GET', '/session/$sessionId/element/$id/text'),
Command.SEND_KEYS_TO_ELEMENT:
('POST', '/session/$sessionId/element/$id/value'),
Command.SEND_KEYS_TO_ACTIVE_ELEMENT:
('POST', '/session/$sessionId/keys'),
Command.UPLOAD_FILE: ('POST', "/session/$sessionId/file"),
Command.GET_ELEMENT_VALUE:
('GET', '/session/$sessionId/element/$id/value'),
Command.GET_ELEMENT_TAG_NAME:
('GET', '/session/$sessionId/element/$id/name'),
Command.IS_ELEMENT_SELECTED:
('GET', '/session/$sessionId/element/$id/selected'),
Command.SET_ELEMENT_SELECTED:
('POST', '/session/$sessionId/element/$id/selected'),
Command.IS_ELEMENT_ENABLED:
('GET', '/session/$sessionId/element/$id/enabled'),
Command.IS_ELEMENT_DISPLAYED:
('GET', '/session/$sessionId/element/$id/displayed'),
Command.GET_ELEMENT_LOCATION:
('GET', '/session/$sessionId/element/$id/location'),
Command.GET_ELEMENT_LOCATION_ONCE_SCROLLED_INTO_VIEW:
('GET', '/session/$sessionId/element/$id/location_in_view'),
Command.GET_ELEMENT_SIZE:
('GET', '/session/$sessionId/element/$id/size'),
Command.GET_ELEMENT_RECT:
('GET', '/session/$sessionId/element/$id/rect'),
Command.GET_ELEMENT_ATTRIBUTE:
('GET', '/session/$sessionId/element/$id/attribute/$name'),
Command.GET_ELEMENT_PROPERTY:
('GET', '/session/$sessionId/element/$id/property/$name'),
Command.GET_ALL_COOKIES: ('GET', '/session/$sessionId/cookie'),
Command.ADD_COOKIE: ('POST', '/session/$sessionId/cookie'),
Command.GET_COOKIE: ('GET', '/session/$sessionId/cookie/$name'),
Command.DELETE_ALL_COOKIES:
('DELETE', '/session/$sessionId/cookie'),
Command.DELETE_COOKIE:
('DELETE', '/session/$sessionId/cookie/$name'),
Command.SWITCH_TO_FRAME: ('POST', '/session/$sessionId/frame'),
Command.SWITCH_TO_PARENT_FRAME: ('POST', '/session/$sessionId/frame/parent'),
Command.SWITCH_TO_WINDOW: ('POST', '/session/$sessionId/window'),
Command.CLOSE: ('DELETE', '/session/$sessionId/window'),
Command.GET_ELEMENT_VALUE_OF_CSS_PROPERTY:
('GET', '/session/$sessionId/element/$id/css/$propertyName'),
Command.IMPLICIT_WAIT:
('POST', '/session/$sessionId/timeouts/implicit_wait'),
Command.EXECUTE_ASYNC_SCRIPT: ('POST', '/session/$sessionId/execute_async'),
Command.SET_SCRIPT_TIMEOUT:
('POST', '/session/$sessionId/timeouts/async_script'),
Command.SET_TIMEOUTS:
('POST', '/session/$sessionId/timeouts'),
Command.DISMISS_ALERT:
('POST', '/session/$sessionId/dismiss_alert'),
Command.W3C_DISMISS_ALERT:
('POST', '/session/$sessionId/alert/dismiss'),
Command.ACCEPT_ALERT:
('POST', '/session/$sessionId/accept_alert'),
Command.W3C_ACCEPT_ALERT:
('POST', '/session/$sessionId/alert/accept'),
Command.SET_ALERT_VALUE:
('POST', '/session/$sessionId/alert_text'),
Command.W3C_SET_ALERT_VALUE:
('POST', '/session/$sessionId/alert/text'),
Command.GET_ALERT_TEXT:
('GET', '/session/$sessionId/alert_text'),
Command.W3C_GET_ALERT_TEXT:
('GET', '/session/$sessionId/alert/text'),
Command.SET_ALERT_CREDENTIALS:
('POST', '/session/$sessionId/alert/credentials'),
Command.CLICK:
('POST', '/session/$sessionId/click'),
Command.W3C_ACTIONS:
('POST', '/session/$sessionId/actions'),
Command.W3C_CLEAR_ACTIONS:
('DELETE', '/session/$sessionId/actions'),
Command.DOUBLE_CLICK:
('POST', '/session/$sessionId/doubleclick'),
Command.MOUSE_DOWN:
('POST', '/session/$sessionId/buttondown'),
Command.MOUSE_UP:
('POST', '/session/$sessionId/buttonup'),
Command.MOVE_TO:
('POST', '/session/$sessionId/moveto'),
Command.GET_WINDOW_SIZE:
('GET', '/session/$sessionId/window/$windowHandle/size'),
Command.SET_WINDOW_SIZE:
('POST', '/session/$sessionId/window/$windowHandle/size'),
Command.GET_WINDOW_POSITION:
('GET', '/session/$sessionId/window/$windowHandle/position'),
Command.SET_WINDOW_POSITION:
('POST', '/session/$sessionId/window/$windowHandle/position'),
Command.SET_WINDOW_RECT:
('POST', '/session/$sessionId/window/rect'),
Command.GET_WINDOW_RECT:
('GET', '/session/$sessionId/window/rect'),
Command.MAXIMIZE_WINDOW:
('POST', '/session/$sessionId/window/$windowHandle/maximize'),
Command.W3C_MAXIMIZE_WINDOW:
('POST', '/session/$sessionId/window/maximize'),
Command.SET_SCREEN_ORIENTATION:
('POST', '/session/$sessionId/orientation'),
Command.GET_SCREEN_ORIENTATION:
('GET', '/session/$sessionId/orientation'),
Command.SINGLE_TAP:
('POST', '/session/$sessionId/touch/click'),
Command.TOUCH_DOWN:
('POST', '/session/$sessionId/touch/down'),
Command.TOUCH_UP:
('POST', '/session/$sessionId/touch/up'),
Command.TOUCH_MOVE:
('POST', '/session/$sessionId/touch/move'),
Command.TOUCH_SCROLL:
('POST', '/session/$sessionId/touch/scroll'),
Command.DOUBLE_TAP:
('POST', '/session/$sessionId/touch/doubleclick'),
Command.LONG_PRESS:
('POST', '/session/$sessionId/touch/longclick'),
Command.FLICK:
('POST', '/session/$sessionId/touch/flick'),
Command.EXECUTE_SQL:
('POST', '/session/$sessionId/execute_sql'),
Command.GET_LOCATION:
('GET', '/session/$sessionId/location'),
Command.SET_LOCATION:
('POST', '/session/$sessionId/location'),
Command.GET_APP_CACHE:
('GET', '/session/$sessionId/application_cache'),
Command.GET_APP_CACHE_STATUS:
('GET', '/session/$sessionId/application_cache/status'),
Command.CLEAR_APP_CACHE:
('DELETE', '/session/$sessionId/application_cache/clear'),
Command.GET_NETWORK_CONNECTION:
('GET', '/session/$sessionId/network_connection'),
Command.SET_NETWORK_CONNECTION:
('POST', '/session/$sessionId/network_connection'),
Command.GET_LOCAL_STORAGE_ITEM:
('GET', '/session/$sessionId/local_storage/key/$key'),
Command.REMOVE_LOCAL_STORAGE_ITEM:
('DELETE', '/session/$sessionId/local_storage/key/$key'),
Command.GET_LOCAL_STORAGE_KEYS:
('GET', '/session/$sessionId/local_storage'),
Command.SET_LOCAL_STORAGE_ITEM:
('POST', '/session/$sessionId/local_storage'),
Command.CLEAR_LOCAL_STORAGE:
('DELETE', '/session/$sessionId/local_storage'),
Command.GET_LOCAL_STORAGE_SIZE:
('GET', '/session/$sessionId/local_storage/size'),
Command.GET_SESSION_STORAGE_ITEM:
('GET', '/session/$sessionId/session_storage/key/$key'),
Command.REMOVE_SESSION_STORAGE_ITEM:
('DELETE', '/session/$sessionId/session_storage/key/$key'),
Command.GET_SESSION_STORAGE_KEYS:
('GET', '/session/$sessionId/session_storage'),
Command.SET_SESSION_STORAGE_ITEM:
('POST', '/session/$sessionId/session_storage'),
Command.CLEAR_SESSION_STORAGE:
('DELETE', '/session/$sessionId/session_storage'),
Command.GET_SESSION_STORAGE_SIZE:
('GET', '/session/$sessionId/session_storage/size'),
Command.GET_LOG:
('POST', '/session/$sessionId/log'),
Command.GET_AVAILABLE_LOG_TYPES:
('GET', '/session/$sessionId/log/types'),
Command.CURRENT_CONTEXT_HANDLE:
('GET', '/session/$sessionId/context'),
Command.CONTEXT_HANDLES:
('GET', '/session/$sessionId/contexts'),
Command.SWITCH_TO_CONTEXT:
('POST', '/session/$sessionId/context'),
Command.FULLSCREEN_WINDOW:
('POST', '/session/$sessionId/window/fullscreen'),
Command.MINIMIZE_WINDOW:
('POST', '/session/$sessionId/window/minimize')
}上面这些command只是selenium中的，appium还有自己增加的command
在appium中的webdriver类中有_addCommands这个方法，这个方法会遍历所有的父类，只要父类也有_addCommands方法，则执行一遍，所以appium初始化后的command会更多，接口也就更多，这也就是说其扩展了selenium。
def _addCommands(self):
# call the overridden command binders from all mixin classes
for mixin_class in filter(lambda x: x is not self.__class__, self.__class__.__mro__):
if hasattr(mixin_class, self._addCommands.__name__):
getattr(mixin_class, self._addCommands.__name__, None)(self)
self.command_executor._commands[Command.TOUCH_ACTION] = \
('POST', '/session/$sessionId/touch/perform')
self.command_executor._commands[Command.MULTI_ACTION] = \
('POST', '/session/$sessionId/touch/multi/perform')
self.command_executor._commands[Command.GET_CURRENT_PACKAGE] = \
('GET', '/session/$sessionId/appium/device/current_package')
self.command_executor._commands[Command.SET_IMMEDIATE_VALUE] = \
('POST', '/session/$sessionId/appium/element/$id/value')
self.command_executor._commands[Command.LAUNCH_APP] = \
('POST', '/session/$sessionId/appium/app/launch')
self.command_executor._commands[Command.CLOSE_APP] = \
('POST', '/session/$sessionId/appium/app/close')
self.command_executor._commands[Command.END_TEST_COVERAGE] = \
('POST', '/session/$sessionId/appium/app/end_test_coverage')
self.command_executor._commands[Command.RESET] = \
('POST', '/session/$sessionId/appium/app/reset')
self.command_executor._commands[Command.OPEN_NOTIFICATIONS] = \
('POST', '/session/$sessionId/appium/device/open_notifications')
self.command_executor._commands[Command.REPLACE_KEYS] = \
('POST', '/session/$sessionId/appium/element/$id/replace_value')
self.command_executor._commands[Command.GET_SETTINGS] = \
('GET', '/session/$sessionId/appium/settings')
self.command_executor._commands[Command.UPDATE_SETTINGS] = \
('POST', '/session/$sessionId/appium/settings')
self.command_executor._commands[Command.LOCATION_IN_VIEW] = \
('GET', '/session/$sessionId/element/$id/location_in_view')
self.command_executor._commands[Command.CLEAR] = \
('POST', '/session/$sessionId/element/$id/clear')小节
- 协议是抽象类，只规定了操作、接口和传参数据格式。
- appium扩展了selenium，appium服务器也实现了selenium的接口功能，只是实现方式不同，当然也有appium特有的功能接口（web不具备的，手机具备的特有功能）。
- 所有的操作在客户端，最终都通过execute方法来请求服务器，并封装响应。
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