Fiddle - Fastly

main
manifest
deps
main
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Run
package main

import (
	"context"
	"fmt"
	"time"

	"github.com/fastly/compute-sdk-go/fsthttp"
	"github.com/flosch/pongo2/v6"
)

type invoiceItem struct {
	Name  string
	Price float64
}

func main() {
	fsthttp.ServeFunc(func(ctx context.Context, w fsthttp.ResponseWriter, r *fsthttp.Request) {

		// Invoice item data
		invoiceItems := []invoiceItem{
			{"Pet Food", 19.99},
			{"Leash", 10.75},
			{"Shampoo", 9.99},
		}

		// Calculate total price from invoice items
		totalPrice := 0.0
		for _, item := range invoiceItems {
			totalPrice += item.Price
		}

		// Invoice create date and due date
		now := time.Now()
		due := now.AddDate(0, 0, 30) // 30 days from now

		// Create context object for template
		tplCtx := pongo2.Context{
			// Set template data to context
			"page_title":    "Sample Invoice, powered by Fastly",
			"vendor_title":  "Fastly Invoice",
			"address":       "P.O. Box 78266<br/>San Francisco, CA 94107 ",
			"customer":      "Example Corp.<br />billing@example.com",
			"payment":       "Credit card",
			"date_created":  now.Format("Jan _2 2006"),
			"date_due":      due.Format("Jan _2 2006"),
			"invoice_items": invoiceItems,
			"total_price":   totalPrice,
			"invoice_num":   "10937248",

			// Set template CSS style
			"css_style": invoiceStyle,
		}

		// Render the template with context data
		out, err := invoiceTemplateTpl.Execute(tplCtx)
		if err != nil {
			w.WriteHeader(500)
			fmt.Fprintf(w, "Error executing template")
			return
		}

		w.Header().Set("Content-Type", "text/html; charset=utf-8")
		fmt.Fprintln(w, out)
	})
}

// invoiceTemplate with template language script
// Credit to https://github.com/sparksuite/simple-html-invoice-template
const invoiceTemplate = `{% autoescape off %}<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8" />
    <title>{{page_title}}</title>
    <style>{{css_style}}</style>
  </head>

  <body>
    <div class="invoice-box">
      <table cellpadding="0" cellspacing="0">
        <tr class="top">
          <td colspan="2">
            <table>
              <tr>
                <td class="title">{{vendor_title}}</td>
                <td>
                  Invoice #: {{invoice_num}}<br />
                  Created: {{date_created}}<br />
                  Due: {{date_due}}
                </td>
              </tr>
            </table>
          </td>
        </tr>

        <tr class="information">
          <td colspan="2">
            <table>
              <tr>
                <td>{{address}}</td>
                <td>{{customer}}</td>
              </tr>
            </table>
          </td>
        </tr>

        <tr class="heading"><td>Item</td><td>Price</td></tr>

        {% for item in invoice_items %}
        <tr class="item">
          <td>{{item.Name}}</td>
          <td>${{item.Price|floatformat:2}}</td>
        </tr>
        {% endfor %}

        <tr class="total">
          <td></td>
          <td>Total: ${{total_price|floatformat:2}}</td>
        </tr>
      </table>
    </div>
  </body>
</html>{% endautoescape %}
`

var invoiceTemplateTpl = pongo2.Must(pongo2.FromString(invoiceTemplate))

// invoiceStyle is the styles for the invoice HTML
const invoiceStyle = `.invoice-box {
  max-width: 800px;
  margin: auto;
  padding: 30px;
  border: 1px solid #eee;
  box-shadow: 0 0 10px rgba(0, 0, 0, 0.15);
  font-size: 16px;
  line-height: 24px;
  font-family: 'Helvetica Neue', 'Helvetica', Helvetica, Arial, sans-serif;
  color: #555;
}

.invoice-box table {
  width: 100%;
  line-height: inherit;
  text-align: left;
}

.invoice-box table td {
  padding: 5px;
  vertical-align: top;
}

.invoice-box table tr td:nth-child(2) {
  text-align: right;
}

.invoice-box table tr.top table td {
  padding-bottom: 20px;
}

.invoice-box table tr.top table td.title {
  font-size: 45px;
  line-height: 45px;
  color: #333;
}

.invoice-box table tr.information table td {
  padding-bottom: 40px;
}

.invoice-box table tr.heading td {
  background: #eee;
  border-bottom: 1px solid #ddd;
  font-weight: bold;
}

.invoice-box table tr.details td {
  padding-bottom: 20px;
}

.invoice-box table tr.item td {
  border-bottom: 1px solid #eee;
}

.invoice-box table tr.item.last td {
  border-bottom: none;
}

.invoice-box table tr.total td:nth-child(2) {
  border-top: 2px solid #eee;
  font-weight: bold;
}

@media only screen and (max-width: 600px) {
  .invoice-box table tr.top table td {
    width: 100%;
    display: block;
    text-align: center;
  }

  .invoice-box table tr.information table td {
    width: 100%;
    display: block;
    text-align: center;
  }
}

/** RTL **/
.invoice-box.rtl {
  direction: rtl;
  font-family: Tahoma, 'Helvetica Neue', 'Helvetica', Helvetica, Arial, sans-serif;
}

.invoice-box.rtl table {
  text-align: right;
}

.invoice-box.rtl table tr td:nth-child(2) {
  text-align: left;
}
`