Dom Note (v): Common JavaScript events and Ajax summaries

I. Common event types

1. Mouse events

Event name	Description
OnClick	Trigger when mouse clicks
Ondbclick	Trigger when mouse double-click
OnMouseDown	Triggered when the left mouse button is pressed
OnMouseUp	Triggered when Mouse is released
onmouseover	triggered when the mouse cursor moves over an object
OnMouseMove	Trigger when mouse moves
onmouseout	Triggers when the mouse cursor leaves an object

PS: When the left mouse button is clicked, the onclick, onmousedown, onmouseup three events are triggered simultaneously, and the event handler executes in order of:onmousedown>onmouseup> OnClick. Because the action that is generated by the mouse is definitely before the mouse is released, and once pressed plus one release, it represents a single click, so the onclick is finally executed.

2. Keyboard Events

Event name	Description
onkeypress	Trigger after a key is pressed
OnKeyDown	Triggered when a key is pressed
OnKeyUp	Triggered when a key is released

PS: The operation on the keyboard also triggers these three events, and the order in which the handlers are executed is onkeydown>onkeypress>onkeyup. Reason See mouse events.

3. Page Events

Event name	Description
OnError	triggered when a page error occurs
OnLoad	triggered when page load is complete
OnResize	browser window size when the table is triggered
Onscroll	triggered when the position of the browser scroll bar is changed
OnUnload	Triggered when the page is unloaded

4. Form Events

event name	description
onblur	element loses focus when
onchange
onfocus when the element loses focus and the element content changes	element triggers when focus is received
onsubmit	trigger when a form is submitted

Second, JavaScript Ajax summary

1. Create a Xhr object

Method	Description
New ActiveXObject ("Microsoft.XMLHTTP")	Applies to I support window. ActiveXObject's IE5 and IE6, etc.
New XMLHttpRequest ()	Suitable for Ie7+/ff/chrome/safari/opera, etc.

2. Properties and methods of XHR objects

Property or method	Description
ReadyState	Communication status, value 0~4, see the following text
onReadyStateChange	This event is triggered when the readystate changes
ResponseText	Text Format document returned by the server
Responsexml	XML format documents returned by the server
Status	Status codes, such as 100,200,404,500
StatusText	Text corresponding to the status code (Ok/not Found)
Abort ()	Abort the current request
Open (Method,url)	Open a request
Send (args)	Send Request
setRequestHeader (Key,value)	Set the requested header
getResponseHeader (Key)	Gets the header value of the response
getAllResponseHeaders ()	Returns all header information as a key-value pair

3. ReadyState Properties

Code	Description
0	Represents an uninitialized state. To create an uninitialized XHR object
1	Represents the connection status. The open method has been called, ready to send the request
2	Represents the Send status. The Send method has been called and the response data has not been received
3	Represents the receiving State, has received header information for the HTTP response, and is receiving the response content
4	Represents the loaded state, when the response has been fully received

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Dom Note (v): Common JavaScript events and Ajax summaries