Web automation: 8.1 how to send JS instructions in the browser

Suggested reading object ： No front-end Foundation , Can't Javascript ,web automation （selenium） The small white

web automated testing , why selenium Still need to learn js Instructions ？

The previous sections talked about selenium The operation of , But there are some browser operations （ Such as ： Page scrolling 、 Time choice 、 Documents, etc. ） Not directly through selenium Realization . therefore , We also need to know some simple js Instructions , By sending js Instructions let the browser perform the corresponding operation .

js What is it? ？

HTML Only responsible for static display
Javascript The programming language used by front-end Engineers . effect ： Give Way web The dynamic effect of web pages .

Almost all browsers have built-in Javascript execution environment , So you can directly in the browser – Developer Tools –Console Write and execute js command .

selenium Schematic diagram

js How to control the browser ？

DOM（Document object model）
document object , Represents the current entire web page . Input document, Will return the code of this web page .
I won't talk about the details here , If you are interested, you can check the information yourself （ I'm also the front-end Xiaobai , I'm afraid that if I don't speak clearly, it will mislead everyone ）

practice ：

1、 Define a name, And print name

Print Syntax ：console.log(name)

2、 Element localization

stay python in find_element(‘id’, ‘kw’) adopt webdriver Turn into js Instructions getElementById(“kw”), So the two effects are the same .
js The instruction can only modify the front-end display , Refresh the page and restore it to its original .

#  Locate Baidu input box elements 
el = document.getElementById("kw")  

#  Modify the of this element value value （selenium Only properties can be obtained , Properties cannot be modified ）
el.value = ' Flower test '		

#  The input box is grayed out and cannot be modified 
el.disabled = true

#  The input box changes back to the inputable state 		
el.disabled = false	

#  Empty web page . This method can be updated or modified , Even rewrite the whole html
document.body.innerText = ''