我正在使用django和reportlab工具生成动态PDF报告。报告中的所有数据都来自数据库。
我正在使用reportlab生成动态PDF报告，该报告包含来自数据库的数据。我的问题是每当我重启Apache服务器时，我的PDF报告数据都在变化。生成的报告使用Django查询来显示数据。但是当我重新启动apache服务器时，正确的数据不会出现在报告中。
我检查了我在django视图中写的所有查询。另外我注意到每次重启Apache服务器都会显示不同的结果。所以我不认为这是我的django查询的问题。有没有解决这个问题的方法？
如果我重新启动apache服务器已经生成的报告的数据会发生变化，这个问题的原因是什么，任何解决方案？
或者是由于apache服务器？
这是源代码。我认为StringIO被错误地放置了。
buffer = StringIO()
def analysis_report(request, sample_no, contact_person):
"""
This function generates the analysis report by using the
client information, transformer details, sample data and
test results of respective analysis.
"""
response = HttpResponse(mimetype='application/pdf')
response['Content-Disposition'] = 'attachment;filename=ANALYSIS_REPORT.pdf'
doc = SimpleDocTemplate(buffer)
document = []
doc.sample_no = sample_no
doc.contact_person = contact_person
image = Paragraph(stamp_image, STYLES['NORMAL_RIGHT'])
document.append(image)
# BUILTIN FUNCTION TO GENERATE THE DOCUMENT.
doc.build(document, onLaterPages=header_footer)
pdf = buffer.getvalue()
response.write(pdf)
return response
提前致谢
答案 0 :(得分：3)
首先，您的案例中的一个大问题可能是buffer = StringIO()不在函数范围内，但您在函数中使用它。
我不确定你到底在做什么 - 你给我们的代码是整个工作PDF中最微小的代码片段 - 但这里有几个指针来自一个只需要做2个非常庞大的PDF包的人对于django项目：
onPage=，那么每个回调也应在您的课程中单独定义所以这是一个示例views.py：
@check_requirments
def pdf(request) :
"""
Download a PDF
"""
response = HttpResponse(mimetype='application/pdf')
response['Content-Disposition'] = 'attachment; filename=new.pdf'
pdf = MyPdf(response)
pdf.add_first_page()
pdf.add_second_page()
pdf.add_disclosures()
pdf.build()
return response
我的Pdf课程的一个例子：
# Page Setup
PAGE_WIDTH, PAGE_HEIGHT = landscape(letter)
class MyPdf():
"""
My PDF
"""
document = None
def __init__(self, file_like_handle=None):
self.document = BaseDocTemplate(file_like_handle, pagesize=landscape(letter))
self.build_templates()
def build_templates(self):
first_page_frames = []
#First Page Title Frame
frame_title = Frame(.25*inch, PAGE_HEIGHT-(1.75*inch), PAGE_WIDTH-(inch*.5), inch*.5, id="frame_title", showBoundary=0)
first_page_frames.append(frame_title)
# First Page Body Frames
frame_body = Frame(.5*inch, PAGE_HEIGHT-(8*inch), PAGE_WIDTH-(inch), inch*6.25, id="frame_body", showBoundary=0)
first_page_frames.append(frame_body)
# Second Page Body Frame
frame_body_full = Frame(.5*inch, PAGE_HEIGHT-(8*inch), PAGE_WIDTH-(inch), inch*7, id="frame_body_full", showBoundary=0)
templates = []
templates.append(PageTemplate(frames=first_page_frames, id="first_page", onPage=self.first_page))
templates.append(PageTemplate(frames=[frame_body_full], id="child_pages", onPage=self.child_pages))
templates.append(PageTemplate(frames=[frame_body_full], id="child_pages", onPage=self.last_page))
self.document.addPageTemplates(templates)
def first_page(self, canvas, doc):
"""
First page has an image header and footer
"""
canvas.saveState()
canvas.drawInlineImage(settings.MEDIA_ROOT + "../static/pdf-header-landscape.png", inch*.25, PAGE_HEIGHT-(1.25 * inch), PAGE_WIDTH-(.5*inch), ((11/8)*inch))
canvas.drawInlineImage(settings.MEDIA_ROOT + "../static/pdf-footer-landscape.png", inch*.25, inch*.25, PAGE_WIDTH-(.5*inch), (.316*inch))
canvas.restoreState()
def child_pages(self, canvas, doc):
"""
Second page has a smaller header and the same footer
"""
canvas.saveState()
canvas.setFillColor(HexColor("#f4f3f1"))
canvas.rect(inch*.25, PAGE_HEIGHT-(.25 * inch), PAGE_WIDTH-(.5*inch), -(.5*inch), fill=1, stroke=0)
canvas.setFillColor(HexColor("#e5b53b"))
canvas.setFont('Gotham-Bold', 16)
canvas.drawString(inch*.5, PAGE_HEIGHT-((.6)*inch), "PAGE")
canvas.setFillColor(HexColor("#00355f"))
canvas.drawString(inch*1.75, PAGE_HEIGHT-((.6)*inch), "OVERVIEW")
canvas.drawInlineImage(settings.MEDIA_ROOT + "../static/pdf-footer-landscape.png", inch*.25, inch*.25, PAGE_WIDTH-(.5*inch), (.316*inch))
canvas.restoreState()
def build(self):
return self.document.build(self.elements)
def add_first_page(self):
sample = getSampleStyleSheet()
style_title = copy.deepcopy(sample['BodyText'])
style_title.fontSize = 18
style_title.textColor = HexColor("#00355f")
style_body = copy.deepcopy(sample['BodyText'])
style_body.fontSize = 10
style_body.alignment = reportlab.lib.enums.TA_LEFT
style_body.spaceBefore = 25
style_body.spaceAfter = 15
style_body.textColor = HexColor("#000000")
style_body.leading = 14
self.elements.append(Paragraph("""<font color="#e5b53b">PAGE</font>OVERVIEW""", style_title))
self.elements.append(FrameBreak())
self.elements.append(Paragraph("""Lorem ipsum dolor sit amet, consectetur adipiscing elit. Aenean elementum malesuada euismod. Praesent ut ante risus. Aenean eleifend massa elit, non adipiscing ipsum. Integer et arcu tortor, a bibendum metus. Maecenas eget nulla id sem placerat dignissim sit amet et ligula. Donec vitae mi mauris. Praesent lacinia, mauris at malesuada bibendum, metus eros molestie ipsum, sed consequat dolor diam interdum ipsum. Phasellus consectetur auctor laoreet. Suspendisse vel nisl lacus, vitae auctor dui.""", style_body))
# ADD A CUSTOM REPORTLAB CANVAS OBJECT
self.elements.append(SomeGraph())
self.elements.append(Paragraph("""Our strategic allocations for each strategy are determined by our Dynamic Strategic Asset Allocation process - the Science of Dynamic Investing. Our proprietary mathematical model uses updated Price Matters<super>®</super> capital market assumptions (expected return, risk and correlation figures) to determine the optimal allocation to each asset class to achieve the goals of each strategy within the assigned risk tolerance and time horizon. The Art of Dynamic Investing enables us to adapt to changing economic and political realities as we reposition strategies with tactical tilts to the strategic allocations as we see value and momentum of various asset classes being affected during the year. <font color="#e5b53b">The chart below</font> shows the strategic weightings and the tactical allocations to each asset class as of the close of business on the date cited.""", style_body))
self.elements.append(NextPageTemplate("child_pages"))
self.elements.append(PageBreak())
def add_second_page(self):
sample = getSampleStyleSheet()
style_title = copy.deepcopy(sample['BodyText'])
style_title.fontSize = 18
style_title.textColor = HexColor("#00355f")
style_body = copy.deepcopy(sample['BodyText'])
style_body.fontSize = 10
style_body.alignment = reportlab.lib.enums.TA_LEFT
style_body.spaceBefore = 25
style_body.spaceAfter = 15
style_body.textColor = HexColor("#000000")
style_body.leading = 14
self.elements.append(Paragraph("""Morbi posuere erat non nunc faucibus rhoncus. Donec at ante at tellus vehicula gravida. Praesent vulputate viverra neque, ut consectetur turpis vestibulum at. Integer interdum diam sed leo vehicula in viverra mauris venenatis. Morbi tristique pretium nunc vel ultrices. Fusce vitae augue lorem, et feugiat lorem. Donec sit amet nulla eget elit feugiat euismod rutrum ut magna. Pellentesque condimentum, tellus at rutrum egestas, dui neque dapibus risus, malesuada mollis risus eros id ligula. Fusce id cursus nulla. Etiam porttitor vulputate tellus eu blandit. Donec elementum erat sed tellus dapibus eleifend. Pellentesque sagittis, libero ac sodales laoreet, erat turpis fringilla est, vel accumsan nunc nisi eget orci. Integer condimentum libero in tellus lacinia ultricies quis ac odio. Vivamus justo urna, faucibus vitae bibendum dapibus, condimentum et ligula. Nullam interdum velit at orci blandit nec suscipit lorem lobortis. Pellentesque purus nunc, pulvinar vitae ullamcorper id, rhoncus sit amet diam.""", style_body))
def add_disclosures(self):
sample = getSampleStyleSheet()
style_d = copy.deepcopy(sample['BodyText'])
style_d.fontSize = 8
style_d.alignment = reportlab.lib.enums.TA_LEFT
style_d.textColor = HexColor("#9D8D85")
self.elements.append(NextPageTemplate("last_page"))
self.elements.append(PageBreak())
self.elements.append(Paragraph("""Important Disclosures""", style_d))
self.elements.append(Paragraph("""Copyright 2012 Francis Yaconiello All Rights Reserved.""", style_d))
注意：我没有测试过这个类，我基本上从我已经拥有的类中获取了很多特定于应用程序的信息，并将其减少以便于摘要。这是为了让您了解我如何将PDF设置为最佳实践。