- 使用Json场景
- Json基本介绍
- 在Django Model中使用Json
- 我们在开发网站的时候，有时候只需要更新数据给前端，而不是刷新整个页面，比如讲我们的model里的全部或者部分数据返回给前端，这个时候，前端为了效率，往往使用ajax，后端django发送数据的时候往往采用json协议，也就是发送json串给前端。同时，前端也可以传递json数据到web后端。
- Models -> JSON
JSON(JavaScript Object Notation) 是一种轻量级的数据交换格式。 易于人阅读和编写。同时也易于机器解析和生成。
{
"result_count": 3,
"results": [
{
"_href": "/ws.v1/lswitch/3ca2d5ef-6a0f-4392-9ec1-a6645234bc55",
"type": "LogicalSwitchConfig"
},
{
"_href": "/ws.v1/lswitch/81f51868-2142-48a8-93ff-ef612249e025",
"type": "LogicalSwitchConfig"
},
]
}前段html文件
<div class="container">
<div class="container">
<h3>Poems:</h3>
<ul>
<li>Results:</li>
</ul>
<button class="btn get-more">Get More Poems</button>
</div>
</div>
$('.get-more').click(function () {
$.ajax({
// 通过get请求获取更多的pome信息
type: "GET",
url: "/ajax/more",
dataType: 'json',
success: function (data) {
// 先将内容转换成字符串
json_str = JSON.stringify(data)
// 再将字符串格式化
json_data = JSON.parse(json_str)
// 遍历json_data
for (var i in json_data) {
item = json_data[i];
$('ul').append('<li>' + item.poem_id + " " + item.author + '</li>')
}
}
})
});
【views.py】
from django.http import Http404, HttpResponse
def more_poems(request):
if request.is_ajax():
objects = Poem.objects.all()
# [{author:'allen',title:'1'},{}]
data = get_json_objects(objects, Poem)
print(str(data) + "这是data more_poems77777777777777777777")
return HttpResponse(data, content_type='application/json')
else:
raise Http404
def json_filed(field_data):
if isinstance(field_data, str):
return "\"" + field_data + "\""
if isinstance(field_data, bool):
if field_data == 'False':
return 'false'
else:
return 'true'
return str(field_data)
def json_encode_dict(dict_data):
print(str(dict_data) + "这是dict_data json_encode_dict333333333333333")
json_data = "{"
for (k, v) in dict_data.items():
json_data = json_data + json_filed(k) + ": " + json_filed(v) + ", "
json_data = json_data[:-2] + "}"
print(str(json_data) + "这是json_data json_encode_dict44444444444444444")
return json_data
def json_encode_list(list_data):
print(str(list_data) + "这是list_fata json_encode_list2222222222222222222")
json_res = "["
for item in list_data:
json_res = json_res + json_encode_dict(item) + ", "
print(str(json_res[:-2]) + "]" + "这是json_res json_encode_list555555555555555555555")
return json_res[:-2] + "]"
def get_json_objects(objects, model_meta):
print(str(objects) + "这是objects get_json_objects111111111111111111111111")
concrete_model = Poem._meta.concrete_model
list_data = []
for obj in objects:
dict_data = {}
for field in concrete_model._meta.local_fields:
if field.name == 'id':
continue
value = field.value_from_object(obj)
dict_data[field.name] = value
list_data.append(dict_data)
data = json_encode_list(list_data)
print(str(data) + "这是data get_json_objects66666666666666666666666")
return data
【urls.py】
urlpatterns = [
url(r'ajax/more/$', view=views.more_poems),
]
数据的处理过程如下
[<Poem: 静夜思>, <Poem: 早发白帝城>, <Poem: 陌上桑>, <Poem: 锄禾日当午>]这是objects get_json_objects111111111111111111111111
[{'poem_id': 0, 'author': '李白', 'title': '静夜思'}, {'poem_id': 1, 'author': '王维', 'title': '早发白帝城'}, {'poem_id': 3, 'author': '李白', 'title': '陌上桑'}, {'poem_id': 4, 'author': '王维', 'title': '锄禾日当午'}]这是list_fata json_encode_list2222222222222222222
{'poem_id': 0, 'author': '李白', 'title': '静夜思'}这是dict_data json_encode_dict333333333333333
{"poem_id": 0, "author": "李白", "title": "静夜思"}这是json_data json_encode_dict44444444444444444
{'poem_id': 1, 'author': '王维', 'title': '早发白帝城'}这是dict_data json_encode_dict333333333333333
{"poem_id": 1, "author": "王维", "title": "早发白帝城"}这是json_data json_encode_dict44444444444444444
{'poem_id': 3, 'author': '李白', 'title': '陌上桑'}这是dict_data json_encode_dict333333333333333
{"poem_id": 3, "author": "李白", "title": "陌上桑"}这是json_data json_encode_dict44444444444444444
{'poem_id': 4, 'author': '王维', 'title': '锄禾日当午'}这是dict_data json_encode_dict333333333333333
{"poem_id": 4, "author": "王维", "title": "锄禾日当午"}这是json_data json_encode_dict44444444444444444
[{"poem_id": 0, "author": "李白", "title": "静夜思"}, {"poem_id": 1, "author": "王维", "title": "早发白帝城"}, {"poem_id": 3, "author": "李白", "title": "陌上桑"}, {"poem_id": 4, "author": "王维", "title": "锄禾日当午"}]这是json_res json_encode_list555555555555555555555
[{"poem_id": 0, "author": "李白", "title": "静夜思"}, {"poem_id": 1, "author": "王维", "title": "早发白帝城"}, {"poem_id": 3, "author": "李白", "title": "陌上桑"}, {"poem_id": 4, "author": "王维", "title": "锄禾日当午"}]这是data get_json_objects66666666666666666666666
[{"poem_id": 0, "author": "李白", "title": "静夜思"}, {"poem_id": 1, "author": "王维", "title": "早发白帝城"}, {"poem_id": 3, "author": "李白", "title": "陌上桑"}, {"poem_id": 4, "author": "王维", "title": "锄禾日当午"}]这是data more_poems77777777777777777777前段html文件
<div class="container">
<label>Poems</label>
<textarea class="textArea" id="textArea" rows="10" cols="70"> </textarea>
<button class="btn add-poem">Add Poem</button>
</div>【views.py】
from django.http import Http404, HttpResponse
def add(request):
if request.is_ajax() and request.POST:
json_str = request.POST.get('poems')
data = "post success"
json_list = ast.literal_eval(json_str)
for item in json_list:
new_obj = Poem()
for filed in item:
setattr(new_obj, filed, item[filed])
print(new_obj.author, new_obj.title, new_obj.poem_id)
new_obj.save()
return HttpResponse(data, content_type='application/text')
else:
return Http404
$('.add-poem').click(function () {
$.ajax({
type: "POST",
url: "/ajax/add/",
dataType: 'text',
data: {"poems": $(".textArea").val()},
success: function (data) {
alert(data);
}
});
});
【urls.py】
urlpatterns = [
url(r'ajax/add/$', view=views.add),
]
提交数据的格式
[{"poem_id": 10, "author": "排骨", "title": "Django"}]