Go

This guide explains how to generate an HTML string using Go's standard template engine and convert it to PDF by sending it to pdfg's API.

Technical Overview

Create a Go template
Pass data to the template to generate an HTML string
Send the generated HTML string to pdfg's API to convert it to PDF

Sample

Defining the Template

<!-- templates/invoice.html -->
<!DOCTYPE html>
<html>
  <head></head>
  <body>
    <div class="invoice">
      <h1>Invoice</h1>
      <table>
        <thead>
          <tr>
            <th>Item</th>
            <th>Amount</th>
          </tr>
        </thead>
        <tbody>
          {{range .Items}}
          <tr>
            <td>{{.Name}}</td>
            <td>{{.Price}} USD</td>
          </tr>
          {{end}}
        </tbody>
      </table>
      <p class="total">Total: {{.Total}} USD</p>
    </div>
  </body>
</html>

Using the Template and Generating PDF

// main.go
package main

import (
	"bytes"
	"encoding/json"
	"html/template"
	"io"
	"net/http"
	"os"
)

type Item struct {
Name string
Price int
}

type Invoice struct {
Items []Item
Total int
}

type PdfgRequest struct {
HTML string `json:"html"`
PdfOptions map[string]interface{} `json:"pdfOptions"`
}

func main() {
// Load template
tmpl, err := template.ParseFiles("templates/invoice.html")
if err != nil {
panic(err)
}

    // Prepare data
    invoice := Invoice{
    	Items: []Item{
    		{Name: "Product A", Price: 1000},
    		{Name: "Product B", Price: 2000},
    	},
    	Total: 3000,
    }

    // Generate HTML string
    var buf bytes.Buffer
    if err := tmpl.Execute(&buf, invoice); err != nil {
    	panic(err)
    }

    // Create request body
    reqBody := PdfgRequest{
    	HTML: buf.String(),
    	PdfOptions: map[string]interface{}{
    		"format": "A4",
    	},
    }

    jsonData, err := json.Marshal(reqBody)
    if err != nil {
    	panic(err)
    }

    // Request to pdfg's API
    req, err := http.NewRequest("POST", "https://api.pdfg.net/v1", bytes.NewBuffer(jsonData))
    if err != nil {
    	panic(err)
    }

    req.Header.Set("Content-Type", "application/json")
    req.Header.Set("Authorization", "Bearer YOUR_API_KEY")

    client := &http.Client{}
    resp, err := client.Do(req)
    if err != nil {
    	panic(err)
    }
    defer resp.Body.Close()

    // Save PDF
    if resp.StatusCode == 200 {
    	out, err := os.Create("invoice.pdf")
    	if err != nil {
    		panic(err)
    	}
    	defer out.Close()

    	_, err = io.Copy(out, resp.Body)
    	if err != nil {
    		panic(err)
    	}
    }
}

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