HTML to PDF / Golang Examples
This page contains various examples of using the HTML to PDF API in Golang. The examples are complete and fully functional. Read more about how to convert HTML to PDF in Golang.
Basic examples
- Webpage to PDF file
- Webpage to in-memory PDF
- Webpage to PDF stream
- HTML file to PDF file
- HTML file to in-memory PDF
- HTML file to PDF stream
- HTML string to PDF file
- HTML string to in-memory PDF
- HTML string to PDF stream
- Get info about the current conversion
Advanced examples
- Customize the page size and the orientation
- Put the source URL in the header and the page number in the footer
- Create fillable PDF form
- Zoom the HTML document
- Set PDF metadata
- Create a Powerpoint like presentation from an HTML document
- Convert an HTML document section
- Inject an HTML code
- Convert a responsive web page as it appears on a large device
- Create an in-memory archive (ZIP) and convert it
- Renderer debugging - highlight HTML elements
- Renderer debugging - borders with spacing around HTML elements
Template rendering examples
- Create PDF from JSON data
- Create PDF from XML data
- Create PDF from YAML data
- Create PDF from CSV data
Basic examples
Webpage to PDF file
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Specify the mapping of HTML content width to the PDF page width. // To fine-tune the layout, you can specify an exact viewport width, such as '960px'. client.SetContentViewportWidth("balanced") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "example.pdf") // 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()) } }
Webpage to in-memory PDF
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Run the conversion and store the result in the `pdf` variable. pdf, err := client.ConvertUrl("http://www.example.com") // Check for the conversion error. handleError(err) // at this point the "pdf" variable contains PDF raw data and // can be sent in an HTTP response, saved to a file, etc. } 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()) } }
Webpage to PDF stream
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Create an output stream for the conversion result outputStream, err := os.Create("example.pdf") // Check for a file creation error. handleError(err) // Close the output stream. defer outputStream.Close() // run the conversion and write the result to the output stream. err = client.ConvertUrlToStream("http://www.example.com", outputStream) // 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()) } }
HTML file to PDF file
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Specify the mapping of HTML content width to the PDF page width. // To fine-tune the layout, you can specify an exact viewport width, such as '960px'. client.SetContentViewportWidth("balanced") // Run the conversion and save the result to a file. err := client.ConvertFileToFile("/path/to/MyLayout.html", "MyLayout.pdf") // 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()) } }
HTML file to in-memory PDF
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Run the conversion and store the result in the `pdf` variable. pdf, err := client.ConvertFile("/path/to/MyLayout.html") // Check for the conversion error. handleError(err) // at this point the "pdf" variable contains PDF raw data and // can be sent in an HTTP response, saved to a file, etc. } 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()) } }
HTML file to PDF stream
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Create an output stream for the conversion result outputStream, err := os.Create("MyLayout.pdf") // Check for a file creation error. handleError(err) // Close the output stream. defer outputStream.Close() // run the conversion and write the result to the output stream. err = client.ConvertFileToStream("/path/to/MyLayout.html", outputStream) // 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()) } }
HTML string to PDF file
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Specify the mapping of HTML content width to the PDF page width. // To fine-tune the layout, you can specify an exact viewport width, such as '960px'. client.SetContentViewportWidth("balanced") // Run the conversion and save the result to a file. err := client.ConvertStringToFile("<html><body><h1>Hello World!</h1></body></html>", "HelloWorld.pdf") // 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()) } }
HTML string to in-memory PDF
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Run the conversion and store the result in the `pdf` variable. pdf, err := client.ConvertString("<html><body><h1>Hello World!</h1></body></html>") // Check for the conversion error. handleError(err) // at this point the "pdf" variable contains PDF raw data and // can be sent in an HTTP response, saved to a file, etc. } 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()) } }
HTML string to PDF stream
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Create an output stream for the conversion result outputStream, err := os.Create("HelloWorld.pdf") // Check for a file creation error. handleError(err) // Close the output stream. defer outputStream.Close() // run the conversion and write the result to the output stream. err = client.ConvertStringToStream("<html><body><h1>Hello World!</h1></body></html>", outputStream) // 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()) } }
Get info about the current conversion
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Specify the mapping of HTML content width to the PDF page width. // To fine-tune the layout, you can specify an exact viewport width, such as '960px'. client.SetDebugLog(true) // Run the conversion and save the result to a file. err := client.ConvertFileToFile("/path/to/MyLayout.html", "MyLayout.pdf") // Check for the conversion error. handleError(err) // print URL pointing to the debug log for this request. fmt.Println("Debug log url:", client.GetDebugLogUrl()) // print number of conversion credits remaining in your account. fmt.Println("Remaining credit count:", client.GetRemainingCreditCount()) // print number of credits consumed for this conversion. fmt.Println("Consumed credit count:", client.GetConsumedCreditCount()) // print unique identifier assigned to this conversion job. fmt.Println("Job id:", client.GetJobId()) // print total number of pages in the output document. fmt.Println("Page count:", client.GetPageCount()) // print size of the output data in bytes. fmt.Println("Output size:", client.GetOutputSize()) } 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()) } }
Advanced examples
Customize the page size and the orientation
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetPageSize("Letter") client.SetOrientation("landscape") client.SetNoMargins(true) // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "letter_landscape.pdf") // 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()) } }
Put the source URL in the header and the page number in the footer
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetHeaderHeight("15mm") client.SetFooterHeight("10mm") client.SetHeaderHtml("<a class='pdfcrowd-source-url' data-pdfcrowd-placement='href-and-content'></a>") client.SetFooterHtml("<center><span class='pdfcrowd-page-number'></span></center>") client.SetMarginTop("0") client.SetMarginBottom("0") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "header_footer.pdf") // 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()) } }
Create fillable PDF form
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetEnablePdfForms(true) // Run the conversion and save the result to a file. err := client.ConvertStringToFile("<html><body>Enter name:<input type=text></body></html>", "form.pdf") // 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()) } }
Zoom the HTML document
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetScaleFactor(300) // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "zoom_300.pdf") // 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()) } }
Set PDF metadata
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetAuthor("Pdfcrowd") client.SetTitle("Hello World") client.SetSubject("Demo") client.SetKeywords("Pdfcrowd,demo") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "with_metadata.pdf") // 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()) } }
Create a Powerpoint like presentation from an HTML document
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetPageLayout("single-page") client.SetPageMode("full-screen") client.SetInitialZoomType("fit-page") client.SetOrientation("landscape") client.SetNoMargins(true) // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("https://pdfcrowd.com/api/", "slide_show.pdf") // 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()) } }
Convert an HTML document section
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetElementToConvert("#main") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("https://pdfcrowd.com/api/", "html_part.pdf") // 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()) } }
Inject an HTML code
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetCustomJavascript("el=document.createElement('h2'); el.textContent='Hello from Pdfcrowd API'; el.style.color='red'; el_before=document.getElementsByTagName('h1')[0]; el_before.parentNode.insertBefore(el, el_before.nextSibling)") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "html_inject.pdf") // 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()) } }
Convert a responsive web page as it appears on a large device
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetContentViewportWidth("large") client.SetNoMargins(true) // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("https://getbootstrap.com/", "bootstrap.pdf") // 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()) } }
Create an in-memory archive (ZIP) and convert it
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" "archive/zip" "bytes" "io" "io/ioutil" ) func addFileToArchive(fName string, fPath string, writer *zip.Writer) { fStream, err := os.Open(fPath) handleError(err) var body []byte body, err = ioutil.ReadAll(fStream) handleError(err) var ioWriter io.Writer ioWriter, err = writer.Create(fName) handleError(err) _, err = ioWriter.Write(body) handleError(err) } func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Create a ZIP archive. var buffer bytes.Buffer archive := zip.NewWriter(&buffer) // Add HTML content to the archive. ioWriter, errHtml := archive.Create("index.html") handleError(errHtml) _, errHtml = ioWriter.Write([]byte(`<html> <head> <style> @font-face { font-family: 'OpenSans'; src: url(fonts/OpenSans.ttf) format('truetype'); } h1 { font-family: OpenSans; } </style> </head> <body> <h1>Hello World</h1> <img src='images/logo.png'> </body> </html>`)) handleError(errHtml) // Add required local files to the archive. addFileToArchive("fonts/OpenSans.ttf", "/your-path-to/fonts/OpenSans.ttf", archive) addFileToArchive("images/logo.png", "/your-path-to/images/logo.png", archive) handleError(archive.Flush()) handleError(archive.Close()) inStream := bytes.NewReader(buffer.Bytes()) // Create an output stream for the conversion result outputStream, err := os.Create("HelloFromZip.pdf") // Check for a file creation error. handleError(err) // Close the output stream. defer outputStream.Close() // run the conversion and write the result to the output stream. err = client.ConvertStreamToStream(inStream, outputStream) // 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()) } }
Renderer debugging - highlight HTML elements
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetCustomJavascript("libPdfcrowd.highlightHtmlElements({backgroundColor: 'rgba(255, 191, 0, 0.1)', borderColor:null})") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "highlight_background.pdf") // 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()) } }
Renderer debugging - borders with spacing around HTML elements
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetCustomJavascript("libPdfcrowd.highlightHtmlElements({borderColor: 'orange', backgroundColor: null, padding: '4px', margin: '4px'})") // Run the conversion and save the result to a file. err := client.ConvertUrlToFile("http://www.example.com", "highlight_borders.pdf") // 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()) } }
Template rendering examples
Create PDF from JSON data
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetDataString(`{ "name": "World", "product": "Pdfcrowd API" }`) // Run the conversion and save the result to a file. err := client.ConvertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf") // 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()) } }
Create PDF from XML data
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetDataString(`<?xml version="1.0" encoding="UTF-8"?> <data> <name>World</name> <product>Pdfcrowd API</product> </data>`) // Run the conversion and save the result to a file. err := client.ConvertStringToFile("Hello {{ data.name }} from {{ data.product }}", "output.pdf") // 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()) } }
Create PDF from YAML data
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetDataString(`name: World product: Pdfcrowd API`) // Run the conversion and save the result to a file. err := client.ConvertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf") // 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()) } }
Create PDF from CSV data
package main import ( "os" "fmt" "github.com/pdfcrowd/pdfcrowd-go" ) func main() { // Create an API client instance. client := pdfcrowd.NewHtmlToPdfClient("demo", "demo") // Configure the conversion. client.SetDataString(`name,product World,Pdfcrowd API`) // Run the conversion and save the result to a file. err := client.ConvertStringToFile("Hello {{ name }} from {{ product }}", "output.pdf") // 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()) } }