Selenium Python教程第6章：使用页面对象

6. Page Objects 页面对象

6.1 什么是页面对象模型(POM)？

页面对象模型(Page Objects Model, POM )是一组旨在表示一个或多个网页的类, 用1个类来保存1个网页上所有的元素，相似的网页可以重用此类。
1个网站通常有多个页面，可以用多个页面类对象分别代表各个页面，其好处有：

• web应用测试程序或者爬虫程序的结构更加清晰易懂。
• 对于结构相似的多个网页，可减少重复的代码量
• 如果web页面元素发生变化，只需要修改一处

6.2 使用页面对象的项目结构

使用页面对象的项目的通常结构类似于

 |-- pages
    |--- locators.py
    |--- elements.py
    |--- pages.py
|-- tests
    |--- test_contact_page.py

各文件说明：

• pages.py 定义页面元素，以及针对各元素的操作方法
• locators.py 分离定位字符。通常做法，同一页面的定位器属于同一个类
• elements.py 通常定义1个页面元素的基类，提供set(), get()方法
• test_*.py 测试用例类test case class文件

6.2 源码文件及说明

6.2.1 测试用例类源码

本例 test_contact_page.py 用于在colibri-software.com网站填写 Contact Me表单，判断是否填写结果是否成功

import unittest
from selenium import webdriver
import pages

classTestColibriSoftwareContactMe(unittest.TestCase):defsetUp(self):
        self.driver = webdriver.Firefox()
        self.driver.get("https://www.colibri-software.com")deftest_submit_contact_me_form(self):"""
         "Contact me" 测试表单
        填写各字段，提交表单，验证提交是否成功
        """# 加载主页，本例为 colibri-software.com主页
        contact_page = pages.ContactPage(self.driver)# Checks if the word "Contact" is in titleassert contact_page.is_title_matches()# 向表单各字段填写内容
        contact_page.name_input ='John Doe'
        contact_page.company_name_input ='John Doe\'s paper company'
        contact_page.email_input ='[email protected]'
        contact_page.additional_info_input ='I need a website to sell paper online'# 提前表单
        contact_page.click_submit_form_button()# 验结果是否成功assert contact_page.success_message_is_displayed()deftearDown(self):
        self.driver.close()if __name__ =="__main__":
    unittest.main()

6.2.2 页面对象类源码

pages.py 介绍如何编写页面对象类

from elements import BasePageElement
from locators import ContactPageLocators

classNameElement(BasePageElement):"""
    This class gets the search text from the specified locator
    """# The locator for text box where name is entered
    locator ='wpforms-236-field_0'# Similar classes for other text fields    classCompanyNameElement(BasePageElement):

    locator ='wpforms-236-field_4'classEmailElement(BasePageElement):

    locator ='wpforms-236-field_1'classAdditionalInfoElement(BasePageElement):

    locator ='wpforms-236-field_0'classBasePage(object):"""
    Base class to initialize the base page that will be called from all pages
    """def__init__(self, driver):
        self.driver = driver

classContactPage(BasePage):"""
    Contact page action methods come here
    """# Declares text input fields
    name_input = NameElement()
    company_name_input = CompanyNameElement()
    email_input = EmailElement()
    additional_info_input = AdditionalInfoElement()defis_title_matches(self):"""
        Verifies that the text "Contact" appears in page title
        """return'Contact'in self.driver.title

    defclick_submit_form_button(self):"""
        Submits the form
        """
        element = self.driver.find_element(*ContactPageLocators.SUBMIT_FORM_BUTTON)
        element.click()defsuccess_message_is_displayed(self):
        success_message ='Thanks for contacting us! We will be in touch with you shortly.'return success_message in self.driver.page_source

6.2.3 页面元素基类源码

elements.py 定义1个页面元素的基类，提供set(), get()方法

from selenium.webdriver.support.ui import WebDriverWait

classBasePageElement(object):"""
    Base page class that is initialized on every page object class.
    """def__set__(self, obj, value):"""
        Sets the text to the value supplied
        """
        driver = obj.driver
        WebDriverWait(driver,100).until(lambda driver: driver.find_element_by_id(self.locator))
        driver.find_element_by_id(self.locator).clear()
        driver.find_element_by_id(self.locator).send_keys(value)def__get__(self, obj, owner):"""
        Gets the text of the specified object
        """
        driver = obj.driver
        WebDriverWait(driver,100).until(lambda driver: driver.find_element_by_id(self.locator))
        element = driver.find_element_by_id(self.locator)return element.get_attribute("value")

6.2.4 locators 定位器类
一个好的编程习惯做法是，分离定位字符。在这个例子中，同一页面的定位器属于同一个类。

from selenium.webdriver.common.by import By

classContactPageLocators(object):"""
    A class for all Contact page locators.
    """
    SUBMIT_FORM_BUTTON =(By.CSS_SELECTOR,'button[type="submit"]')classSearchResultsPageLocators(object):"""A class for search results locators. All search results locators should come here"""pass