Generate a document with full height in Go with Go-Resty

In this guide, we'll show you how to generate a document with full height dynamically using Go and the Go-Resty library to convert them to PDF using PDFShift's API.

When you're converting a document, you might want to generate a document with full height dynamically. This can be done by setting the format parameter to the request and passing it a custom "auto" value for the {height} part.

package main

import (
    "encoding/base64"
    "encoding/json"
    "fmt"
    "io/ioutil"
    "github.com/go-resty/resty/v2"
)

func main() {
    // You can get an API key at https://pdfshift.io
    apiKey := "sk_xxxxxxxxxxxx"

    params := map[string]interface{}{
        "source": "https://www.example.com",
        "format": "1280xauto",
    }

    // Marshal the parameters into JSON
    jsonParams, err := json.Marshal(params)
    if err != nil {
        fmt.Println("Error marshaling JSON:", err)
        return
    }
    // Create a new Resty client
    client := resty.New()

    // Perform the request
    resp, err := client.R().
        SetHeader("Content-Type", "application/json").
        SetBasicAuth("api", apiKey).
        SetBody(jsonParams).
        Post("https://api.pdfshift.io/v3/convert/pdf")

    if err != nil {
        fmt.Println("Error performing request:", err)
        return
    }

    // Check response status code
    if resp.StatusCode() >= 400 {
        fmt.Printf("Request failed with status code %d: %s\n", resp.StatusCode(), string(resp.Body()))
        return
    }

    // Save the PDF document
    err = ioutil.WriteFile("result.pdf", resp.Body(), 0644)
    if err != nil {
        fmt.Println("Error saving PDF document:", err)
        return
    }

    fmt.Println("The PDF document was generated and saved to result.pdf")
}

The format parameter can accept various values, such as 'Letter', 'Legal', 'Tabloid', 'Ledger', 'A0', 'A1', 'A2', 'A3', 'A4', 'A5'.

But it can also accept a custom values that is defined per the width and height as follow: {width}x{height}

Both width and height are pixel value by default, but if you precise the unit (in "cm", "mm", "in" or "pt"). That unit will be used instead.

For instance, you can set a format of:

{
    "source": "https://www.example.com",
    "format": "21cmx29,7cm"
}

Now, if you want a "liquid" height, which will analyze the height of the page and use it as your format, you can set the {height} value to auto. So, instead of setting a fixed height such as 'format': '1280x1024', you can set 'format': '1280xauto' and the height will be calculated based on the content of the page.

For further details on the format property and its usage, please refer to our dedicated documentation.

We hope this guide was helpful. If you have any questions or noticed any issues on the code above,
feel free to drop us a line.