Django PDF Render，聚合模板标签显示包含代码 {{ 代理 }}

编程问答 2022-04-24

问题描述

在 views.py 中，我有以下函数来呈现 PDF 视图：

def agent_render_pdf(request,*args,**kwargs):
pk = kwargs.get('pk')
agent = get_object_or_404(Agents,pk=pk)
invoices = Invoice.objects.filter(agent=agent)
invoice_total = invoices.aggregate(Sum('invoice_amount'))

template_path = 'agents/statement.html'

context = {'agent': agent,'invoices':invoices,'invoice_total': invoice_total,}
#Create a Django response object,and specify content_type as pdf
response = HttpResponse(content_type='application/pdf')
#if download:
#response['Content-disposition'] = 'attachment'; filename"report.pdf"'
#if display:
response['Content-disposition']='filename="report.pdf"'
#find the template and render it
template = get_template(template_path)
html = template.render(context)

#create a PDF
pisa_status = pisa.CreatePDF(
    html,dest=response
)
if pisa_status.err:
    return HttpResponse('We had some errors <pre>' +html +'</pre>')
return response

我将其呈现为“statements.html”，如下所示：

<body>

{{ 代理 }}


<div class="table">
    <table>
        <th>Invoice Number</th>
        <th>Invoice Date</th>
        <th>Due Date</th>
        <th>Invoice Amount</th>
        <th>Invoice Age</th>
        {% for i in invoices %}
        <tr>
            <td>{{ i.invoice_number }}</td>
            <td>{{ i.invoice_date }}</td>
            <td>{{ i.invoice_due_date|date:"m/d/Y" }}</td>
            <td>{{ i.invoice_amount }}</td>
            <td>{{ i.InvoiceAge }}</td>
        </tr>
        {% endfor %}
        <tr>
            <td>&nbsp;</td>
            <td>&nbsp;</td>
            <td>total:</td>
            <td>${{ invoice_total }}</td>
            <td>&nbsp;</td>
        </tr>

    </table>
</div>

我的视图基本上按预期呈现，接受invoice_total 显示为

${'invoice_amount__sum': 十进制('2500')}

而不是仅仅证明发票总额为 2,500 美元。我显然得到了我想要的信息，我只是不明白我做错了什么导致格式问题？

完整的PDF是：

Screen capture of PDF output

解决方法

.aggregate() 返回一个字典，因为您可以同时获取多个聚合（想象一下一次选择一个计数、一个最大值和一个最小值，以避免多次查询）

所以只需设置一个密钥并使用它：

invoice_total = invoices.aggregate(total=Sum('invoice_amount'))['total']
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