Python Learning---jsonp learning 180130

Homologous policy mechanism

Origin: protocol://IP: Port " protocol, domain name, port same "

cross-domain: know the other side of the interface, and the data returned by the other party must also be in JSONP format

Problem Description: Ajax requests data across domains, the actual browser has already got the data, but the browser because of the same-origin policy hides the content, do not show us the data. In other words, Ajax cannot request data across domains.

Problem solving: <script src= "" >

tags with src attributes can request data across domains, which is why IMG can refer to images from other sites

Jsonp's prototype: create a callback function and invoke the function on the remote service and pass the JSON data as a parameter to complete the callback.

Jsonp must be a GET request

JSONP Instance one: Using the SRC attribute of the script tag

padding: Is the function that puts the data inside the function and then packages it to the foreground,

Cons: There must be a function in the foreground script that handles a write function, because the essence is to use the function to receive parameters

Correctly add script tags and content dynamically

settigs.py:

' DIRS ': [Os.path.join (Base_dir, ' templates ')],  # Set templates path to Django previous version # ' DIRS ': [],      # comment out the line, this is the Django 2.0.1 Latest Version # ' Django.middleware.csrf.CsrfViewMiddleware ',         ... Omit default configuration Static_url = '/static/' Template_dirs = (Os.path.join (base_dir,  ' templates '),)  # original config # static resource file Staticfiles _dirs = (Os.path.join (base_dir, "statics"),)   # Now add the configuration, here is the tuple, note the comma

Templates/ajax_jquery.html

<! DOCTYPE html>
mysite2/urls.py
From Django.contrib import adminfrom django.urls import pathfrom Blog import viewsfrom django.conf.urls import Urlurlpatte RNS = [      # jquery_ajax  url (r ' ajax-jquery/', views.ajax_jquery),  # jquery_ajax_test  url (r ' Jquery_ajax _test/', views.jquery_ajax_test),]
views.py
From django.shortcuts import Render, httpresponse# Jquery-to-ajaxdef ajax_jquery (Request):    return Render ( Request, ' ajax_jquery.html ') # jquery-to-ajaximport jsondef jquery_ajax_test (Request):    print (' request. POST ', request. POST)    # return HttpResponse (' Hello ')   # error, at this time cross-domain return to scrip label an undefined hello variable     # return HttpResponse (' var hello ')   # Correct, at this time cross-domain return to scrip label a definition but no content of the Hello variable    return httpresponse (' Test ("" Hello ")
Page display:
Dynamically create a Jsonp instance of the script:
settigs.py:
' DIRS ': [Os.path.join (Base_dir, ' templates ')],  # Set templates path to Django previous version # ' DIRS ': [],      # comment out the line, this is the Django 2.0.1 Latest Version # ' Django.middleware.csrf.CsrfViewMiddleware ',         ... Omit default configuration Static_url = '/static/' Template_dirs = (Os.path.join (base_dir,  ' templates '),)  # original config # static resource file Staticfiles _dirs = (Os.path.join (base_dir, "statics"),)   # Now add the configuration, here is the tuple, note the comma
Templates/ajax_jquery.html
<! DOCTYPE html>
mysite2/urls.py
From Django.contrib import adminfrom django.urls import pathfrom Blog import viewsfrom django.conf.urls import Urlurlpatte RNS = [      # jquery_ajax  url (r ' ajax-jquery/', views.ajax_jquery),  # jquery_ajax_test  url (r ' Jquery_ajax _test/', views.jquery_ajax_test),]
views.py
From django.shortcuts import Render, httpresponse# Jquery-to-ajaxdef ajax_jquery (Request):    return Render ( Request, ' ajax_jquery.html ') # jquery-To-ajaxdef jquery_ajax_test (Request):    print (' request. GET ', request. GET)    func = Request. Get.get (' callbacks ', None)    print (' func; ', func)    return HttpResponse ("%s (' World ')"% func)
Page display:
Attention:
There are 2 environments running: Python manage.py runserver 8081
The project itself is: http://127.0.0.1:8080/ajax-jquery/
The realization of jquery to Jsonp
1. Name of the callback function defined with jquery:
$.getjson ("http://127.0.0.1:8081/jquery_ajax_test?callback=?", function (ARG) {    Console.log ("successfully, Hello "+ arg)});
Note that you must add a callback parameter after the URL so that the Getjson method knows to access the service Jsonp, and the question mark behind the callback is the name of a callback function that is automatically generated internally.
2. Use a custom Function name:
Form One: Custom Function + Call the specified function "not recommended" functions Sayhi () {      ...} $.ajax ({    URL: "Http://127.0.0.1:8002/get_byjsonp",    dataType: "Jsonp",  # requires the server to return data in a JSONP format, A function is nested in a data form, otherwise returning the original type    JSONP: ' Callback ',    jsonpcallback: ' Sayhi '}); Note: Jsonp: ' Callback ' + Jsonpcallback: " Sayhi "  --piecing together a key-value pair to send past---->  ' callback ': ' Sayhi ' form two: Custom function + do not specify  " recommended "$.ajax ({    URL:"/http 127.0.0.1:8002/get_byjsonp ",    dataType:" Jsonp ",            //must have, tell the server that this visit is going to be a jsonp result.    Jsonp: ' Callback ',          //jquery help randomly generated: callback= "Wner"    success:function (data) {  # Receive the data from the background to be sent to        alert (data)     });
Getjson of function names defined with jquery--instances
settigs.py:
' DIRS ': [Os.path.join (Base_dir, ' templates ')],  # Set templates path to Django previous version # ' DIRS ': [],      # comment out the line, this is the Django 2.0.1 Latest Version # ' Django.middleware.csrf.CsrfViewMiddleware ',         ... Omit default configuration Static_url = '/static/' Template_dirs = (Os.path.join (base_dir,  ' templates '),)  # original config # static resource file Staticfiles _dirs = (Os.path.join (base_dir, "statics"),)   # Now add the configuration, here is the tuple, note the comma
Templates/ajax_jquery.html
<! DOCTYPE html>
mysite2/urls.py
From Django.contrib import adminfrom django.urls import pathfrom Blog import viewsfrom django.conf.urls import Urlurlpatte RNS = [      # jquery_ajax  url (r ' ajax-jquery/', views.ajax_jquery),  # jquery_ajax_test  url (r ' Jquery_ajax _test/', views.jquery_ajax_test),]
views.py
From django.shortcuts import Render, httpresponse# Jquery-to-ajaxdef ajax_jquery (Request):    return Render ( Request, ' ajax_jquery.html ') # jquery-To-ajaxdef jquery_ajax_test (Request):    print (' request. GET ', request. GET)    func = Request. Get.get (' callback ', None)    print (' func; ', func)    return HttpResponse ("%s (' World 2020 ')"% func)
Page display:
Getjson of use a custom function name--instance:  
settigs.py:
' DIRS ': [Os.path.join (Base_dir, ' templates ')],  # Set templates path to Django previous version # ' DIRS ': [],      # comment out the line, this is the Django 2.0.1 Latest Version # ' Django.middleware.csrf.CsrfViewMiddleware ',         ... Omit default configuration Static_url = '/static/' Template_dirs = (Os.path.join (base_dir,  ' templates '),)  # original config # static resource file Staticfiles _dirs = (Os.path.join (base_dir, "statics"),)   # Now add the configuration, here is the tuple, note the comma
Templates/ajax_jquery.html
<! DOCTYPE html>
mysite2/urls.py
From Django.contrib import adminfrom django.urls import pathfrom Blog import viewsfrom django.conf.urls import Urlurlpatte RNS = [      # jquery_ajax  url (r ' ajax-jquery/', views.ajax_jquery),  # jquery_ajax_test  url (r ' Jquery_ajax _test/', views.jquery_ajax_test),]
views.py
From django.shortcuts import Render, httpresponse# Jquery-to-ajaxdef ajax_jquery (Request):    return Render ( Request, ' ajax_jquery.html ') # jquery-To-ajaxdef jquery_ajax_test (Request):    print (' request. GET ', request. GET)    func = Request. Get.get (' callback ', None)    print (' func; ', func)    return HttpResponse ("%s (' World 2020 ')"% func)
Page display:
. The specified function of the Ajax cross-domain request
settigs.py:
' DIRS ': [Os.path.join (Base_dir, ' templates ')],  # Set templates path to Django previous version # ' DIRS ': [],      # comment out the line, this is the Django 2.0.1 Latest Version # ' Django.middleware.csrf.CsrfViewMiddleware ',         ... Omit default configuration Static_url = '/static/' Template_dirs = (Os.path.join (base_dir,  ' templates '),)  # original config # static resource file Staticfiles _dirs = (Os.path.join (base_dir, "statics"),)   # Now add the configuration, here is the tuple, note the comma
Templates/ajax_jquery.html
<! DOCTYPE html>
mysite2/urls.py
From Django.contrib import adminfrom django.urls import pathfrom Blog import viewsfrom django.conf.urls import Urlurlpatte RNS = [      # jquery_ajax  url (r ' ajax-jquery/', views.ajax_jquery),  # jquery_ajax_test  url (r ' Jquery_ajax _test/', views.jquery_ajax_test),]
views.py
From django.shortcuts import Render, httpresponse# Jquery-to-ajaxdef ajax_jquery (Request):    return Render ( Request, ' ajax_jquery.html ') # jquery-To-ajaxdef jquery_ajax_test (Request):    print (' request. GET ', request. GET)    func = Request. Get.get (' callback ', None)    return HttpResponse ("%s (' World 2020 ')"% func)   # func is [] because no call is needed at all, the foreground is defined
Page display:
Python Learning---jsonp learning 180130