Image to Image / Golang Guide

Overview

This page serves as a guide for using the PDFCrowd API to convert between images formats in Golang applications.

Installation

Clone pdfcrowd-go from Github into your project source folder: 
git clone https://github.com/pdfcrowd/pdfcrowd-go src/github.com/pdfcrowd/pdfcrowd-go
  1. Download pdfcrowd-6.5.0-go.zip.
  2. Import pdfcrowd.go in your code using its package path.

Quick Start

Below are Golang examples to help you quickly get started with the API. Explore our additional examples for more insights. 

package main

import (
    "os"
    "fmt"
    "github.com/pdfcrowd/pdfcrowd-go"
)

func main() {
    // Create an API client instance.
    client := pdfcrowd.NewImageToImageClient("your_username", "your_apikey")

    // Configure the conversion.
    client.SetOutputFormat("jpg")

    // Run the conversion and save the result to a file.
    err := client.ConvertUrlToFile("https://pdfcrowd.com/static/images/logo.png", "logo.jpg")

    // Check for the conversion error.
    handleError(err)
}

func handleError(err error) {
    if err != nil {
        why, ok := err.(pdfcrowd.Error)
        if ok {
            os.Stderr.WriteString(fmt.Sprintf("PDFCrowd Error: %s\n", why))
        } else {
            os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err))
        }

        panic(err.Error())
    }
}
package main

import (
    "os"
    "fmt"
    "github.com/pdfcrowd/pdfcrowd-go"
    "io/ioutil"
)

func readFile(fileName string) []byte {
    content, err := ioutil.ReadFile(fileName)
    handleError(err)
    return content
}

func main() {
    // Create an API client instance.
    client := pdfcrowd.NewImageToImageClient("your_username", "your_apikey")

    // Configure the conversion.
    client.SetOutputFormat("jpg")

    // Run the conversion and save the result to a file.
    err := client.ConvertRawDataToFile(readFile("/path/to/logo.png"), "logo.jpg")

    // Check for the conversion error.
    handleError(err)
}

func handleError(err error) {
    if err != nil {
        why, ok := err.(pdfcrowd.Error)
        if ok {
            os.Stderr.WriteString(fmt.Sprintf("PDFCrowd Error: %s\n", why))
        } else {
            os.Stderr.WriteString(fmt.Sprintf("Generic Error: %s\n", err))
        }

        panic(err.Error())
    }
}

Authentication

Error Handling

It is recommended that you implement error handling to catch errors the API may return. Effective error handling is vital as it ensures application stability and provides clearer diagnostics. See the example code below for guidance on implementing error handling, and refer to this list of status codes for more information. 

// Call the API 

    // Log the complete error
    os.Stderr.WriteString(fmt.Sprintf("PDFCrowd Error: %s\n", why))

    // Log the HTTP status code
    os.Stderr.WriteString(fmt.Sprintf("Status Code: %v\n", why.getStatusCode()))

    // Log the reason code
    os.Stderr.WriteString(fmt.Sprintf("Reason Code: %v\n", why.getReasonCode()))

    // Log the error message
    os.Stderr.WriteString(fmt.Sprintf("Error Message: %v\n", why.getMessage()))

    // Log the documentation link
    os.Stderr.WriteString(fmt.Sprintf("Documentation Link: %v\n", why.getDocumentationLink()))

Troubleshooting

  • If you are receiving an error, refer to the API Status Codes for more information.
  • Use setDebugLog() and getDebugLogUrl() to obtain detailed information about the conversion process, including load errors, load times, browser console output, etc.
  • Consult the FAQ for answers to common questions.
  • Contact us if you need assistance or if there is a feature you are missing.

API Method Reference

Refer to the Image to Image Golang Reference for a description of all API methods.