(PowerShell) 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 .NET Downloads Chilkat .NET Assemblies

Add-Type -Path "C:\chilkat\ChilkatDotNet47-9.5.0-x64\ChilkatDotNet47.dll"

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

$http = New-Object Chilkat.Http

$jsonToken = New-Object Chilkat.JsonObject
$success = $jsonToken.LoadFile("qa_data/tokens/xero-access-token.json")
if ($success -eq $false) {
    $($jsonToken.LastErrorText)
    exit
}

$http.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.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 = New-Object Chilkat.BinData
$success = $http.QuickGetBd($url,$bd)
if ($success -eq $false) {
    $($http.LastErrorText)
    exit
}

$("Response Status Code: " + $http.LastStatus)

if ($http.LastStatus -eq 200) {
    # Success
    # Save to a file..
    $success = $bd.WriteFile("qa_output/penguines.jpg")
}
else {
    # Failed.  bd contains error information..
    $($bd.GetString("utf-8"))
}