Detailed explanation of chrome developer tools

Type: Requesting resources MIME type ;
Initiator Explain how the request was initiated , There are four possible values ：

Parser： The request is made by the page HTML Sent when parsing ;
Redirect： The request is sent by page redirection ;
Script： The request is made script The script handles the sent ;
Other： Requests are sent by other processes , Like on the page link Link Click , Enter in the address field URL Address .

***********************************XHR*****************************
ajax yes asynchronous javascript and XML Abbreviation , Chinese translation is asynchronous javascript and XML, This technology can request additional data from the server without unloading the page , Although the name contains XML, but ajax Communication has nothing to do with data formats .
        ajax It includes the following steps ：1、 establish AJAX object ;2、 issue HTTP request ;3、 Receive data from server ;4、 Update web data

        To sum up, it is ,ajax Through the original XMLHttpRequest The object sends out HTTP request , After getting the data returned by the server , Reprocessing

       ajax The core of technology is XMLHttpRequest object ( abbreviation XHR),XHR Provides a smooth interface for sending requests to the server and parsing server responses , Ability to get more information from the server asynchronously

Supplementary explanation
[XPath]

XPath Is a door in XML The language in which information is found in a document .XPath Used in XML Navigate through elements and attributes in the document . Like in the picture 2 in ,

 
1

 
<a href="https://github.com/NUKnightLab/TimelineJS"> here </a>

here a Labeled Xpath by ：/html/body/div[2]/p[1]/a, Read as ：html Inside body The second part of the label div The first of the labels p Label under a label .

[HTML DOM event ]

HTML DOM Allows us to perform a specific... When an event occurs JavaScript Script , The events here can be ：

Mouse over an element ;
The window or frame is resized ;
The text is selected ;
The user is in HTML Click on the element ;
A keyboard key is pressed …
This is executed when the event occurs javascript Scripts are event listeners .

[DOM The breakpoint ]

DOM The breakpoint （DOM Breakpoints） You can monitor a certain DOM Modified situation , stay Elements Right click on an element in to set breakpoints in three different situations ：

Child node modification
Self property modification
Its own node is deleted
After setting DOM Breakpoints It will appear in the list DOM The breakpoint .

Once monitored DOM When modified , The breakpoint will be located to the code that performs the modification , This is for those that bind multiple events DOM Debugging is very helpful .

[XMLHttpRequest]

XMLHttpRequest It's a browser interface , bring Javascript Can be done HTTP(S) signal communication .XMLHttpRequest Object is used to exchange data with the server in the background , In this way, we can

Update pages without reloading them
Request data from server after page has been loaded
Receive data from server after page has been loaded
Send data to the server in the background