渲染从SimpleDocTemplate构建的ReportLab pdf [英] rendering a ReportLab pdf built from SimpleDocTemplate

问题描述

我有一个django应用程序，该应用程序当前使用用户可以下载的画布生成pdf.我创建一个StringIO缓冲区，做一些事情，然后发送调用response.write.

I've a got a django app that currently generates pdfs using a canvas that the user can download. I create a StringIO buffer, do some stuff and then send call response.write.

# Set up response
response = HttpResponse(mimetype='application/pdf')
response['Content-Disposition'] = 'attachment; filename=menu-%s.pdf' % str(menu_id)
# buffer
buff = StringIO()

# Create the pdf object
p = canvas.Canvas(buff)

# Add some elements... then

p.showPage()
p.save()

# Get the pdf from the buffer and return the response
pdf = buff.getvalue()
buff.close()
response.write(pdf)

我现在想使用platypus和SimpleDocTemplate构建pdf并已编写

I now want to build my pdf using platypus and SimpleDocTemplate and have written this

# Set up response
response = HttpResponse(mimetype='application/pdf')
pdf_name = "menu-%s.pdf" % str(menu_id)
response['Content-Disposition'] = 'attachment; filename=%s' % pdf_name

menu_pdf = SimpleDocTemplate(pdf_name, rightMargin=72,
                            leftMargin=72, topMargin=72, bottomMargin=18)

# container for pdf elements
elements = []

styles=getSampleStyleSheet()
styles.add(ParagraphStyle(name='centered', alignment=TA_CENTER))

# Add the content as before then...

menu_pdf.build(elements)
response.write(menu_pdf)
return response

但是这不起作用，它会创建一个无法打开的错误pdf.我猜想这行

But this doesn't work, it creates a bad pdf that cannot be opened. I presume the line

response.write(menu_pdf)

不正确.

如何渲染pdf?

推荐答案

您的错误实际上是一个非常简单的错误.这只是尝试写错东西的问题.在您的代码中， menu_pdf 不是PDF，而是 SimpleDocTemplate ，并且PDF已存储在 pdf_name 中，尽管我怀疑> pdf_name 是路径名而不是文件对象.要对其进行修复，请像在原始代码中一样更改代码以使用内存文件:

Your error is actually a pretty simple one. It's just a matter of trying to write the wrong thing. In your code, menu_pdf is not a PDF, but a SimpleDocTemplate, and the PDF has been stored in pdf_name, although here I suspect pdf_name is a path name rather than a file object. To fix it, change your code to use a memory file like you did in your original code:

# Set up response
response = HttpResponse(mimetype='application/pdf')
pdf_name = "menu-%s.pdf" % str(menu_id)
response['Content-Disposition'] = 'attachment; filename=%s' % pdf_name

buff = StringIO()

menu_pdf = SimpleDocTemplate(buff, rightMargin=72,
                            leftMargin=72, topMargin=72, bottomMargin=18)

# container for pdf elements
elements = []

styles=getSampleStyleSheet()
styles.add(ParagraphStyle(name='centered', alignment=TA_CENTER))

# Add the content as before then...

menu_pdf.build(elements)
response.write(buff.getvalue())
buff.close()
return response

我不确定文档中是否提到使用文件对象而不是Platypus的路径，但是如果您深入研究代码，将会发现这是可能的.

I'm not sure if using file objects rather than paths with Platypus is mentioned in the documentation, but if you dig into the code you'll see that it is possible.

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