定位策略

在DOM中标识一个或多个特定元素的方法.

A locator is a way to identify elements on a page. It is the argument passed to the Finding element methods.

Check out our encouraged test practices for tips on locators, including which to use when and why to declare locators separately from the finding methods.

元素选择策略

在 WebDriver 中有 8 种不同的内置元素定位策略:

定位器 Locator描述
class name定位class属性与搜索值匹配的元素(不允许使用复合类名)
css selector定位 CSS 选择器匹配的元素
id定位 id 属性与搜索值匹配的元素
name定位 name 属性与搜索值匹配的元素
link text定位link text可视文本与搜索值完全匹配的锚元素
partial link text定位link text可视文本部分与搜索值部分匹配的锚点元素。如果匹配多个元素,则只选择第一个元素。
tag name定位标签名称与搜索值匹配的元素
xpath定位与 XPath 表达式匹配的元素

Relative Locators

Selenium 4 introduces Relative Locators (previously called as Friendly Locators). These locators are helpful when it is not easy to construct a locator for the desired element, but easy to describe spatially where the element is in relation to an element that does have an easily constructed locator.

How it works

Selenium uses the JavaScript function getBoundingClientRect() to determine the size and position of elements on the page, and can use this information to locate neighboring elements.
find the relative elements.

Relative locator methods can take as the argument for the point of origin, either a previously located element reference, or another locator. In these examples we’ll be using locators only, but you could swap the locator in the final method with an element object and it will work the same.

Let us consider the below example for understanding the relative locators.

Relative Locators

Available relative locators

Above

If the email text field element is not easily identifiable for some reason, but the password text field element is, we can locate the text field element using the fact that it is an “input” element “above” the password element.

By emailLocator = RelativeLocator.with(By.tagName("input")).above(By.id("password"));
email_locator = locate_with(By.TAG_NAME, "input").above({By.ID: "password"})
var emailLocator = RelativeBy.WithLocator(By.TagName("input")).Above(By.Id("password"));
email_locator = {relative: {tag_name: 'input', above: {id: 'password'}}}
let emailLocator = locateWith(By.tagName('input')).above(By.id('password'));
val emailLocator = RelativeLocator.with(By.tagName("input")).above(By.id("password"))

Below

If the password text field element is not easily identifiable for some reason, but the email text field element is, we can locate the text field element using the fact that it is an “input” element “below” the email element.

By passwordLocator = RelativeLocator.with(By.tagName("input")).below(By.id("email"));
password_locator = locate_with(By.TAG_NAME, "input").below({By.ID: "email"})
var passwordLocator = RelativeBy.WithLocator(By.TagName("input")).Below(By.Id("email"));
password_locator = {relative: {tag_name: 'input', below: {id: 'email'}}}
let passwordLocator = locateWith(By.tagName('input')).below(By.id('email'));
val passwordLocator = RelativeLocator.with(By.tagName("input")).below(By.id("email"))

Left of

If the cancel button is not easily identifiable for some reason, but the submit button element is, we can locate the cancel button element using the fact that it is a “button” element to the “left of” the submit element.

By cancelLocator = RelativeLocator.with(By.tagName("button")).toLeftOf(By.id("submit"));
cancel_locator = locate_with(By.TAG_NAME, "button").to_left_of({By.ID: "submit"})
var cancelLocator = RelativeBy.WithLocator(By.tagName("button")).LeftOf(By.Id("submit"));
cancel_locator = {relative: {tag_name: 'button', left: {id: 'submit'}}}
let cancelLocator = locateWith(By.tagName('button')).toLeftOf(By.id('submit'));
val cancelLocator = RelativeLocator.with(By.tagName("button")).toLeftOf(By.id("submit"))

Right of

If the submit button is not easily identifiable for some reason, but the cancel button element is, we can locate the submit button element using the fact that it is a “button” element “to the right of” the cancel element.

By submitLocator = RelativeLocator.with(By.tagName("button")).toRightOf(By.id("cancel"));
submit_locator = locate_with(By.TAG_NAME, "button").to_right_of({By.ID: "cancel"})
var submitLocator = RelativeBy.WithLocator(By.tagName("button")).RightOf(By.Id("cancel"));
submit_locator = {relative: {tag_name: 'button', right: {id: 'cancel'}}}
let submitLocator = locateWith(By.tagName('button')).toRightOf(By.id('cancel'));
val submitLocator = RelativeLocator.with(By.tagName("button")).toRightOf(By.id("cancel"))

Near

If the relative positioning is not obvious, or it varies based on window size, you can use the near method to identify an element that is at most 50px away from the provided locator. One great use case for this is to work with a form element that doesn’t have an easily constructed locator, but its associated input label element does.

By emailLocator = RelativeLocator.with(By.tagName("input")).near(By.id("lbl-email"));
email_locator = locate_with(By.TAG_NAME, "input").near({By.ID: "lbl-email"})
var emailLocator = RelativeBy.WithLocator(By.tagName("input")).Near(By.Id("lbl-email"));
email_locator = {relative: {tag_name: 'input', near: {id: 'lbl-email'}}}
let emailLocator = locateWith(By.tagName('input')).near(By.id('lbl-email'));
val emailLocator = RelativeLocator.with(By.tagName("input")).near(By.id("lbl-email"));

Chaining relative locators

You can also chain locators if needed. Sometimes the element is most easily identified as being both above/below one element and right/left of another.

By submitLocator = RelativeLocator.with(By.tagName("button")).below(By.id("email")).toRightOf(By.id("cancel"));
submit_locator = locate_with(By.TAG_NAME, "button").below({By.ID: "email"}).to_right_of({By.ID: "cancel"})
var submitLocator = RelativeBy.WithLocator(By.tagName("button")).Below(By.Id("email")).RightOf(By.Id("cancel"));
submit_locator = {relative: {tag_name: 'button', below: {id: 'email'}, right: {id: 'cancel'}}}
let submitLocator = locateWith(By.tagName('button')).below(By.id('email')).toRightOf(By.id('cancel'));
val submitLocator = RelativeLocator.with(By.tagName("button")).below(By.id("email")).toRightOf(By.id("cancel"))