Extracted logic from views - fixed tests.

The logic was coupled with the views which made things difficult
to reuse if you wanted to use the pdf generation somehwere else
than in a view.

With this patch, the logic has been moved to `utils.py` and should
be more easy to reuse.

Tests have been adapted and made compatible with django > 1.7

1 files changed, 86 insertions, 1 deletions

diff --git a/wkhtmltopdf/utils.py b/wkhtmltopdf/utils.py
index f9d7ac1..87b214c 100644
--- a/wkhtmltopdf/utils.py
+++ b/wkhtmltopdf/utils.py
@@ -6,6 +6,10 @@ import os
 import re
 import sys
 import shlex
+from tempfile import NamedTemporaryFile
+
+from django.template.context import Context, RequestContext
+from django.utils.encoding import smart_text
 
 try:
     from urllib.request import pathname2url
@@ -103,6 +107,59 @@ def wkhtmltopdf(pages, output=None, **kwargs):
 
     return check_output(ck_args, **ck_kwargs)
 
+def convert_to_pdf(filename, header_filename=None, footer_filename=None, cmd_options=None):
+    # Clobber header_html and footer_html only if filenames are
+    # provided. These keys may be in self.cmd_options as hardcoded
+    # static files.
+    cmd_options = cmd_options if cmd_options else {}
+
+    if header_filename is not None:
+        cmd_options['header_html'] = header_filename
+    if footer_filename is not None:
+        cmd_options['footer_html'] = footer_filename
+    return wkhtmltopdf(pages=[filename], **cmd_options)
+
+def render_pdf_from_template(input_template, header_template, footer_template, context, cmd_options=None):
+    debug = getattr(settings, 'WKHTMLTOPDF_DEBUG', settings.DEBUG)
+    cmd_options = cmd_options if cmd_options else {}
+
+    input_file = header_file = footer_file = None
+    header_filename = footer_filename = None
+
+    try:
+        input_file = render_to_temporary_file(
+            template=input_template,
+            context=context,
+            prefix='wkhtmltopdf', suffix='.html',
+            delete=(not debug)
+        )
+
+        if header_template:
+            header_file = render_to_temporary_file(
+                template=header_template,
+                context=context,
+                prefix='wkhtmltopdf', suffix='.html',
+                delete=(not debug)
+            )
+            header_filename = header_file.name
+
+        if footer_template:
+            footer_file = render_to_temporary_file(
+                template=footer_template,
+                context=context,
+                prefix='wkhtmltopdf', suffix='.html',
+                delete=(not debug)
+            )
+            footer_filename = footer_file.name
+
+        return convert_to_pdf(filename=input_file.name,
+                              header_filename=header_filename,
+                              footer_filename=footer_filename,
+                              cmd_options=cmd_options)
+    finally:
+        # Clean up temporary files
+        for f in filter(None, (input_file, header_file, footer_file)):
+            f.close()
 
 def content_disposition_filename(filename):
     """
@@ -144,7 +201,6 @@ def pathname2fileurl(pathname):
 def make_absolute_paths(content):
     """Convert all MEDIA files into a file://URL paths in order to
     correctly get it displayed in PDFs."""
-
     overrides = [
         {
             'root': settings.MEDIA_ROOT,
@@ -173,3 +229,32 @@ def make_absolute_paths(content):
                                       occur[len(x['url']):])
 
     return content
+
+def render_to_temporary_file(template, context, mode='w+b', bufsize=-1,
+                                 suffix='.html', prefix='tmp', dir=None,
+                                 delete=True):
+    # make sure the context is a context object
+    if not isinstance(context, (Context, RequestContext)):
+        context = Context(context)
+
+    content = smart_text(template.render(context))
+    content = make_absolute_paths(content)
+
+    try:
+        # Python3 has 'buffering' arg instead of 'bufsize'
+        tempfile = NamedTemporaryFile(mode=mode, buffering=bufsize,
+                                      suffix=suffix, prefix=prefix,
+                                      dir=dir, delete=delete)
+    except TypeError:
+        tempfile = NamedTemporaryFile(mode=mode, bufsize=bufsize,
+                                      suffix=suffix, prefix=prefix,
+                                      dir=dir, delete=delete)
+
+    try:
+        tempfile.write(content.encode('utf-8'))
+        tempfile.flush()
+        return tempfile
+    except:
+        # Clean-up tempfile if an Exception is raised.
+        tempfile.close()
+        raise