Serialization 序列化

创建表

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',)

进行序列化的类(第一种)

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')

    """上面的相当于form表单验证 缺点: 如果表的列比较多呢"""

    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

序列化类常用的方法和属性

snippet = Snippet(code='foo = "bar"\n')

serializer = SnippetSerializer(snippet)

serializer.data  # .data存储model的数据

# {'id': 2, 'title': u'', 'code': u'print "hello, world"\n', 'linenos': False, 'language': u'python', 'style': u'friendly'}

#序列化转成json数据#

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', ...

序列化的类(第二种)简单明了

class SnippetSerializer(serializers.ModelSerializer):

class Meta:

    model = Snippet 表名

    fields = ('id', 'title', 'code', 'linenos', 'language', 'style')  列

view文件

get(获取):

    snippets = Snippet.objects.all() #从model取出所有数据

    serializer = SnippetSerializer(snippets, many=True)  # 进行序列化

    return JsonResponse(serializer.data, safe=False) # 返回客户端

post(创建新的数据):

    data = JSONParser().parse(request) # 反序列化客户端数据

    serializer = SnippetSerializer(data=data)  # 实例化

    if serializer.is_valid():   # 检查数据是否有问题

        serializer.save() # 创建数据

        return JsonResponse(serializer.data, status=201) # 返回给客户端刚刚创建的数据

    return JsonResponse(serializer.errors, status=400)

put(更新数据):

    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(删除数据):

    snippet.delete()

    return HttpResponse(status=204)