首先提供一些关于应用程序的信息:我希望能够上传pdf文件,将pdf文件转换为图像(每个pdf页面都有一个图像)。这些图像将在网站上显示,pdf可以下载:到目前为止我有这个:
def upload_to(path):
def upload_callback(instance, filename):
return '%s' % os.path.join(settings.MEDIA_ROOT, path, str(instance), filename)
return upload_callback
class Document(models.Model):
name = models.TextField()
pdf_file = models.FileField(upload_to=upload_to('pdfs'))
images = models.ManyToManyField('Image', null=True, blank=True)
class Image(models.Model):
image = models.ImageField(upload_to='pdfimages')
现在创建图像和图像对象我覆盖了Document类的保存功能:我看起来像这样:
def save(self, *args, **kwargs):
path = os.path.join(settings.MEDIA_ROOT, 'pdfs', self.name)
imagepath = os.path.join(settings.MEDIA_ROOT, 'pdfimages')
if os.path.exists(path):
for file_ in os.listdir(path):
if file_ == self.pdf_file.name:
continue
super(Document, self).save(*args, **kwargs)
save_to = os.path.join(path, os.path.splitext(self.pdf_file.name)[0] +
'_page.png')
pdffile = os.path.join(path, self.pdf_file.name)
args = ['convert', '-density', '100', '-depth',
'8', '-quality', '85', pdffile, save_to ]
subprocess.check_call(args, stdout=sys.stdout, stderr=sys.stderr)
for file_ in os.listdir(path):
if file_.endswith('png'):
try:
shutil.move((os.path.join(settings.MEDIA_ROOT,
'pdfs', self.name, file_)),
imagepath)
except Exception:
pass
for file_ in os.listdir(imagepath):
i, created = Image.objects.get_or_create(image="pdfimages/%s" % file_)
首先,代码不是很好,其次是最重要的操作仍然缺失。将图像添加到文档意味着更新m2m关系。现在我有两个问题:
super(文档,自我).save(* args,** kwargs) 在代码中间。
编辑:
一旦你理解了参数,这实际上很容易,谢谢