(Ruby) Xero Download Attachment for an Item (such as an Invoice)

Demonstrates how to download a particular attachment for a particular Xero item.

For more information, see https://developer.xero.com/documentation/api/attachments#GET

Chilkat Ruby Downloads install from rubygems.org gem install chilkat or download... Ruby Library for Windows, MacOS, Linux, Alpine Linux

require 'chilkat'

# This example requires the Chilkat API to have been previously unlocked.
# See Global Unlock Sample for sample code.

http = Chilkat::CkHttp.new()

jsonToken = Chilkat::CkJsonObject.new()
success = jsonToken.LoadFile("qa_data/tokens/xero-access-token.json")
if (success == false)
    print jsonToken.lastErrorText() + "\n";
    exit
end

http.put_AuthToken(jsonToken.stringOf("access_token"))

# Replace the value here with an actual tenant ID obtained from this example:
# Get Xero Tenant IDs
http.SetRequestHeader("Xero-tenant-id","83299b9e-5747-4a14-a18a-a6c94f824eb7")

http.put_Accept("application/json")

# The example to list Xero attachments shows how to get attachment information.
# Here's a sample JSON response obtained form listing attachments:
# Your application can get the AttachmentID's and filenames from it.

# {
#   "Id": "24bfbcb9-dec9-4d33-835c-8f165d776766",
#   "Status": "OK",
#   "ProviderName": "Chilkat2222",
#   "DateTimeUTC": "\/Date(1587213296972)\/",
#   "Attachments": [
#     {
#       "AttachmentID": "daf106e2-8634-4349-bfcc-86c1df0793b2",
#       "FileName": "penguins.jpg",
#       "Url": "https://api.xero.com/api.xro/2.0/Invoices/0032f627-3156-4d30-9b1c-4d3b994dc921/Attachments/penguins.jpg",
#       "MimeType": "image/jpg",
#       "ContentLength": 777835
#     }
#   ]
# }

url = "https://api.xero.com/api.xro/2.0/{$Endpoint}/{$Guid}/Attachments/{$AttachmentId}"

# Endpoint can be Invoices, Receipts, CreditNotes, PurchaseOrders, etc.
http.SetUrlVar("Endpoint","Invoices")

# Guid is the ID of the item, such as the InvoiceID.
http.SetUrlVar("Guid","0032f627-3156-4d30-9b1c-4d3b994dc921")

# AttachmentId is the ID of the particular attachment to be downloaded
http.SetUrlVar("AttachmentId","daf106e2-8634-4349-bfcc-86c1df0793b2")

# Download the attachment data into bd.
bd = Chilkat::CkBinData.new()
success = http.QuickGetBd(url,bd)
if (success == false)
    print http.lastErrorText() + "\n";
    exit
end

print "Response Status Code: " + http.get_LastStatus().to_s() + "\n";

if (http.get_LastStatus() == 200)
    # Success
    # Save to a file..
    success = bd.WriteFile("qa_output/penguines.jpg")
else
    # Failed.  bd contains error information..
    print bd.getString("utf-8") + "\n";
end