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View
summary
effect ：
The view accepts web request , And respond to Web request
The essence ：
The view is One Python The function in
Response content ：
Webpage
Redirect
Wrong view
404：url Can't find
500： Server internal error
JSON data
URL To configure
The configuration process
stay settings.py It is specified in Root level URL The configuration file ：ROOT_URLCONF = 'project.urls', By default .
urlpatterns:
One url The object of the instance
url object
Regular expressions
View name
name （ Used for reverse parsing ）
url Considerations for matching regularities ：
If you want to go from url To get a value , You need to add parentheses to the regular
The match is correct , There is no need to add a small slash in front /, Usually add at the end
You need to add... Before regularization r Representation string No escape
Introduce other url To configure
Generally, it is created in the application urls.py file , Define the of this application url To configure , In the engineering urls.py Use... In the document include() Method : url(r'^', include('myApp.urls',namespace='myApp')),
Matching process
engineering url-> application url-> View
URL Reverse resolution of （ agent ）：
summary
If in view / Hard coded connections are used in the template , stay url When the configuration changes , Dynamically generate the address of the link .
Solutions
When using links , adopt url Configuration name , Dynamic generation url Address .
effect
Use url The template
The view function
Define views ：
The essence ： A function
View parameters ：
request One HttpRequest Example
adopt url Parameters obtained by regular expression
Location ：
Generally in views.py In the definition of
Wrong view
404 View
Web page not found （url The match didn't work ） When to return to .
You can define yourself .
stay templates define 404.html
request_path: URL causing error .
To configure settings.py
DEBUG If True forever No Would call 404.html page
ALLOWED_HOSTS = [*]
500 View
An error occurred in the view code （ Server code ）.
400 View
The error is the customer's operation .
HttpRequest object
Concept
receive HTTP After the request , It will be created according to the message HttpRequest object
The first parameter of a view is HttpRequest object
Djano Object created , Then the call attempts to pass to the view
attribute
path
The full path of the request （ Domain name and port are not included ）
method
How to express a request , Commonly used GET、POST
encoding
Represents the encoding method of the data submitted by the browser , It's usually utf-8
GET
Dictionary like objects , Contains get All parameters requested
POST
Dictionary like objects , Contains post All parameters requested
FILES
Dictionary like objects , Contains all uploaded files .
COOKIES
Dictionaries , All inclusive cookie
session
Dictionary like objects , Represents the current session
Method
is_ajax()
If it is XMLHttpRequest Sponsored , return True
QueryDict object
request Object GET、POST All objects belong to QueryDict object
Method
get()
effect ： Get value from key
Only one value can be obtained
www.baidu.com/abc?a=1&b=2&c=3
getlist()
Return the value of the key as a list
You can get multiple values
www.baidu.com/abc?a=1&a=2&c=3 ( Note that there are two a)
GET attribute
# obtain get Data transferred
def get1(request):
a = request.GET.get("a")
b = request.GET["b"]
c = request.GET.get("c")
return HttpResponse(a + " " + b + " " + c)
def get2(request):
a = request.GET.getlist('a')
a1 = a[0]
a2 = a[1]
b = request.GET.get('c')
return HttpResponse(a1 + " " + a2 + " " + b)
