Login

A form field for valdating PDF and Microsoft Word document

Author:
jimmylam
Posted:
November 14, 2008
Language:
Python
Version:
1.0
Tags:
pdf microsoft-word-document form-field
Score:
0 (after 2 ratings)

This is form field for PDF or Microsoft Word Document (both .doc and .docx) It will validate the file uploaded as a valid PDF and MS Word Document.

It extends a forms.FileField, so you can put all the arguments relevant to FileField.

IMPORTANT NOTE: The method of validation is actually run thru *nix OS shell command 'file', therefore,

  1. only *nix system can use this class.
  2. The file uploaded must be saved on disk, meaning you need to set your upload handler to use TempoaryFileUploadHandler Only.

(i.e. put this in your settings.py)

FILE_UPLOAD_HANDLERS = ( "django.core.files.uploadhandler.TemporaryFileUploadHandler", )

 1
 2
 3
 4
 5
 6
 7
 8
 9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
from django import forms
from django.utils.translation import ugettext_lazy as _

class UploadedFileInMemoryError(Exception):
	pass
	
class DocField(forms.FileField):
	"""
	This is form field for PDF or Microsoft Word Document (both .doc and .docx)
	It will validate the file uploaded as a valid PDF and MS Word Document.
	~~~~~~~~~
	Usage:
	import DocField
	doc = models.DocField()	
	~~~~~~~~~
	It extends a forms.FileField, so you can put all the arguments relevant to FileField.
	
	IMPORTANT NOTE: The method of validation is actually run thru *nix OS shell command 'file', 
				    therefore, 1. only *nix system can use this class. 
				               2. The file uploaded must be saved on disk, meaning you need to set your upload handler to use TempoaryFileUploadHandler Only.
 	
    # (i.e. put this in your settings.py) 
	FILE_UPLOAD_HANDLERS = (
 		"django.core.files.uploadhandler.TemporaryFileUploadHandler",
 	)
	
	"""
	default_error_messages = {
		'invalid': _(u"No file was submitted. Check the encoding type on the form."),
		'missing': _(u"No file was submitted."),
		'empty': _(u"The submitted file is empty."),
		'not_doc': _(u"Upload a valid document. The file you uploaded was not a acceptable document or a corrupted document."),
	}

	def clean(self, data, initial=None):
		super(DocField, self).clean(initial or data)

		#before save check if the writing sample is valid
		import os, re
		from django.forms.util import ValidationError

		match = r'PDF document|Microsoft Office Document|Zip archive data'

		if hasattr(data, 'temporary_file_path'):
			file = data.temporary_file_path()
		else:
			# throw an error because uploaded file in memory 
			raise UploadedFileInMemoryError('The file uploaded is stored in memory instead of disk and the validation cannot be performed.')
						
		out = os.popen('file %s' % file)
		ck = re.search(match, out.read())
		if ck == None:
			raise ValidationError(self.error_messages['not_doc'])
		#  check further for docx file as it's zip file
		if ck.group(0)[0] == 'Z':
			import zipfile
			docx = 'word/document.xml'
			if not zipfile.is_zipfile(file):
				raise ValidationError(self.error_messages['not_doc'])

			zf = zipfile.ZipFile(file)
			if not docx in zf.namelist():
				raise ValidationError(self.error_messages['not_doc'])
		return data

More like this

  1. ImageField for Google App Engine by davepeck 5 years, 4 months ago
  2. File Mimetype Validator (Using python-magic) by BHSPitMonkey 12 months ago
  3. Complex Formsets, Redux by smagala 5 years ago
  4. Sorl Thumbnail + Amazon S3 by skoczen 5 years, 9 months ago
  5. Little middleware that create a facebook user by marinho 7 years, 3 months ago

Comments

Tarken (on November 14, 2008):

In an effort to make this snippet portable, wouldn't it make more sense to look for the magic pattern in the file to identify it as a PDF or doc file?

For example, with PDF, make sure the file begins with "%PDF-" For a Word document, check that it being with "\x31\xbe\x00\x00" or "PO^Q`"

Those are merely taken from a /etc/gnome-vfg-mime-magic file on a Fedora 8 box, but given that specifications for both file formats are now openly available, I'm sure you can verify the true file magic necessary to identify these files.

#

voidberg (on February 3, 2012):

Older Office documents are identified by:

CDF V2 Document

So that should be added to the list.

#

Please login first before commenting.