Django从url保存图像并与ImageField连接

Question

我有models.py:

class Item(models.Model):
    image_file = models.ImageField(upload_to='images')
    image_url = models.URLField()

我希望django自动下载并本地保存图像image_url并"连接"它image_file

它应该如何行动:

1. 我在管理员中粘贴https://docs.djangoproject.com/s/img/site/hdr_logo.gif 到image_url字段中
2. 点击"保存"
3. 在模板中写<img src="{{ item.image_file.url }}">.它显示来自我的服务器的图像,而不是djangoproject.com

我尝试过的:

我已经改写save了Item课程方法.我通过本地保存图像urllib,但我坚持将此保存的图像与image_file字段连接

Answer 1

from django.core.files import File
import os

class Item(models.Model):
    image_file = models.ImageField(upload_to='images')
    image_url = models.URLField()

...

def get_remote_image(self):
    if self.image_url and not self.image_file:
        result = urllib.urlretrieve(self.image_url)
        self.image_file.save(
                os.path.basename(self.image_url),
                File(open(result[0]))
                )
        self.save()

您可以覆盖默认的save()方法以自动调用get_remote_image().

请参阅:https://docs.djangoproject.com/en/dev/topics/db/models/#overriding-model-methods

Answer 2

对于python3

from django.core.files import File
from urllib import request
import os

class Item(models.Model):
    image_file = models.ImageField(upload_to='images')
    image_url = models.URLField()

...

def get_remote_image(self):
    if self.image_url and not self.image_file:
        result = request.urlretrieve(self.image_url)
        self.image_file.save(
                os.path.basename(self.image_url),
                File(open(result[0], 'rb'))
                )
        self.save()

从这里：http : //stackoverflow.com/questions/17960942/attributeerror-module-object-has-no-attribute-urlretrieve

Answer 3

from django.db import models
from django.core.files import File
from urllib.request import urlopen
from tempfile import NamedTemporaryFile

class Item(models.Model):
    image_file = models.ImageField(upload_to='images')
    image_url = models.URLField()

...

def get_remote_image(self):
    if self.image_url and not self.image_file:
        img_temp = NamedTemporaryFile(delete=True)
        img_temp.write(urlopen(self.image_url).read())
        img_temp.flush()
        self.image_file.save(f"image_{self.pk}", File(img_temp))
    self.save()

此解决方案可避免在网址处理过程中收到任何utf-8错误。

它仅适用于python 3.6+，因为f字符串。

检查此链接：https : //twigstechtips.blogspot.com/2012/04/django-programmatically-saving-image.html

Answer 4

Python3

from django.db import models
from django.core.files import File
from urllib.request import urlopen
from tempfile import NamedTemporaryFile

class Item(models.Model):
    image_file = models.ImageField(upload_to='images')
    image_url = models.URLField()

    def save(self, *args, **kwargs):
        if self.image_url and not self.image_file:
            img_temp = NamedTemporaryFile(delete=True)
            img_temp.write(urlopen(self.image_url).read())
            img_temp.flush()
            self.image_file.save(f"image_{self.pk}", File(img_temp))
        super(Item, self).save(*args, **kwargs)

它类似，但在添加“image_url”时自动保存“image_file”