django restframework 序列化

Serialization 序列化

建立表

from django.db import models
from pygments.lexers import get_all_lexers
from pygments.styles import get_all_styles

LEXERS = [item for item in get_all_lexers() if item[1]]
LANGUAGE_CHOICES = sorted([(item[1][0], item[0]) for item in LEXERS])
STYLE_CHOICES = sorted((item, item) for item in get_all_styles())


class Snippet(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    title = models.CharField(max_length=100, blank=True, default='')
    code = models.TextField()
    linenos = models.BooleanField(default=False)
    language = models.CharField(choices=LANGUAGE_CHOICES, default='python', max_length=100)
    style = models.CharField(choices=STYLE_CHOICES, default='friendly', max_length=100)

    class Meta:
        ordering = ('created',)

進行序列化的類(第一種)

from rest_framework import serializers
from snippets.models import Snippet, LANGUAGE_CHOICES, STYLE_CHOICES


class SnippetSerializer(serializers.Serializer):
    id = serializers.IntegerField(read_only=True)
    title = serializers.CharField(required=False, allow_blank=True, max_length=100)
    code = serializers.CharField(style={'base_template': 'textarea.html'})
    linenos = serializers.BooleanField(required=False)
    language = serializers.ChoiceField(choices=LANGUAGE_CHOICES, default='python')
    style = serializers.ChoiceField(choices=STYLE_CHOICES, default='friendly')
    """上面的至關於form表單驗證 缺點: 若是表的列比較多呢"""

    def create(self, validated_data):
        """
        Create and return a new `Snippet` instance, given the validated data.
        """
        return Snippet.objects.create(**validated_data)

    def update(self, instance, validated_data):
        """
        Update and return an existing `Snippet` instance, given the validated data.
        """
        instance.title = validated_data.get('title', instance.title)
        instance.code = validated_data.get('code', instance.code)
        instance.linenos = validated_data.get('linenos', instance.linenos)
        instance.language = validated_data.get('language', instance.language)
        instance.style = validated_data.get('style', instance.style)
        instance.save()
        return instance

序列化類經常使用的方法和屬性

snippet = Snippet(code='foo = "bar"\n')
serializer = SnippetSerializer(snippet)
serializer.data  # .data存儲model的數據
# {'id': 2, 'title': u'', 'code': u'print "hello, world"\n', 'linenos': False, 'language': u'python', 'style': u'friendly'}
#序列化轉成json數據#
content = JSONRenderer().render(serializer.data)
content
# '{"id": 2, "title": "", "code": "print \\"hello, world\\"\\n", "linenos": false, "language": "python", "style": "friendly"}'

#反序列化#

from django.utils.six import BytesIO

stream = BytesIO(content)
data = JSONParser().parse(stream)

serializer = SnippetSerializer(data=data)
serializer.is_valid()
# True
serializer.validated_data
# OrderedDict([('title', ''), ('code', 'print "hello, world"\n'), ('linenos', False), ('language', 'python'), ('style', 'friendly')])
serializer.save()
# <Snippet: Snippet object>

serializer = SnippetSerializer(Snippet.objects.all(), many=True)
serializer.data
# [OrderedDict([('id', 1), ('title', u''), ('code', u'foo = "bar"\n'), ('linenos', False), ('language', 'python'), ('style', ...

序列化的類(第二種)簡單明瞭

class SnippetSerializer(serializers.ModelSerializer):
class Meta:
    model = Snippet 表名
    fields = ('id', 'title', 'code', 'linenos', 'language', 'style')  列

view文件

get(獲取): 
    snippets = Snippet.objects.all() #從model取出全部數據
    serializer = SnippetSerializer(snippets, many=True)  # 進行序列化
    return JsonResponse(serializer.data, safe=False) # 返回客戶端
    
post(建立新的數據):
    data = JSONParser().parse(request) # 反序列化客戶端數據
    serializer = SnippetSerializer(data=data)  # 實例化
    if serializer.is_valid():   # 檢查數據是否有問題
        serializer.save() # 建立數據
        return JsonResponse(serializer.data, status=201) # 返回給客戶端剛剛建立的數據
    return JsonResponse(serializer.errors, status=400)
    
put(更新數據):
    data = JSONParser().parse(request)
    serializer = SnippetSerializer(snippet, data=data)
    if serializer.is_valid():
        serializer.save()
        return JsonResponse(serializer.data)
    return JsonResponse(serializer.errors, status=400)

delete(刪除數據):
    snippet.delete()
    return HttpResponse(status=204)