(Tcl) PayPal Generate QR Code

Generates a QR code for an invoice, by ID.

The QR code is a PNG image in Base64-encoded format that corresponds to the invoice ID.

Note: A QR code can only be generated for an invoice that has been both created and sent.

See also Generate QR Code

Chilkat Tcl Extension Downloads Chilkat Tcl Extension Downloads

load ./chilkat.dll

# Note: Requires Chilkat v9.5.0.64 or greater.

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

# Load our previously obtained access token. (see PayPal OAuth2 Access Token)
set jsonToken [new_CkJsonObject]

CkJsonObject_LoadFile $jsonToken "qa_data/tokens/paypal.json"

# Build the Authorization request header field value.
set sbAuth [new_CkStringBuilder]

# token_type should be "Bearer"
CkStringBuilder_Append $sbAuth [CkJsonObject_stringOf $jsonToken "token_type"]
CkStringBuilder_Append $sbAuth " "
CkStringBuilder_Append $sbAuth [CkJsonObject_stringOf $jsonToken "access_token"]

# Make the initial connection.
# A single REST object, once connected, can be used for many PayPal REST API calls.
# The auto-reconnect indicates that if the already-established HTTPS connection is closed,
# then it will be automatically re-established as needed.
set rest [new_CkRest]

set bAutoReconnect 1
set success [CkRest_Connect $rest "api.sandbox.paypal.com" 443 1 $bAutoReconnect]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkJsonObject $jsonToken
    delete_CkStringBuilder $sbAuth
    delete_CkRest $rest
    exit
}

# ----------------------------------------------------------------------------------------------
# The code above this comment could be placed inside a function/subroutine within the application
# because the connection does not need to be made for every request.  Once the connection is made
# the app may send many requests..
# ----------------------------------------------------------------------------------------------

# Build a path using an invoice ID.
set sbPath [new_CkStringBuilder]

CkStringBuilder_Append $sbPath "/v1/invoicing/invoices/invoice_id/qr-code"
set numReplacements [CkStringBuilder_Replace $sbPath "invoice_id" "INV2-ZG2H-HKAW-PMWU-N6ZR"]

CkRest_AddHeader $rest "Authorization" [CkStringBuilder_getAsString $sbAuth]
# A 500x500 image results in a PNG file of approx. 4K bytes in size.
CkRest_AddQueryParam $rest "width" "500"
CkRest_AddQueryParam $rest "height" "500"
CkRest_AddQueryParam $rest "action" "pay"

# Send the GET request and get the PNG image data as base64.
# A successful JSON response looks like this:
# {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
set sbJsonResponse [new_CkStringBuilder]

set success [CkRest_FullRequestNoBodySb $rest "GET" [CkStringBuilder_getAsString $sbPath] $sbJsonResponse]
if {$success != 1} then {
    puts [CkRest_lastErrorText $rest]
    delete_CkJsonObject $jsonToken
    delete_CkStringBuilder $sbAuth
    delete_CkRest $rest
    delete_CkStringBuilder $sbPath
    delete_CkStringBuilder $sbJsonResponse
    exit
}

set json [new_CkJsonObject]

CkJsonObject_put_EmitCompact $json 0
CkJsonObject_LoadSb $json $sbJsonResponse

puts "Response Status Code = [CkRest_get_ResponseStatusCode $rest]"

# Did we get a 200 success response?
if {[CkRest_get_ResponseStatusCode $rest] != 200} then {
    puts [CkJsonObject_emit $json]
    puts "Failed."
    delete_CkJsonObject $jsonToken
    delete_CkStringBuilder $sbAuth
    delete_CkRest $rest
    delete_CkStringBuilder $sbPath
    delete_CkStringBuilder $sbJsonResponse
    delete_CkJsonObject $json
    exit
}

# If the 200 response is received, the response body contains the PNG data.
# Save the PNG to a file.
set pngData [new_CkBinData]

CkBinData_AppendEncoded $pngData [CkJsonObject_stringOf $json "image"] "base64"
set success [CkBinData_WriteFile $pngData "qa_output/paypal_qr_code.png"]
if {$success == 0} then {
    puts "Failed to save PNG file."
    delete_CkJsonObject $jsonToken
    delete_CkStringBuilder $sbAuth
    delete_CkRest $rest
    delete_CkStringBuilder $sbPath
    delete_CkStringBuilder $sbJsonResponse
    delete_CkJsonObject $json
    delete_CkBinData $pngData
    exit
}

puts "Success."

delete_CkJsonObject $jsonToken
delete_CkStringBuilder $sbAuth
delete_CkRest $rest
delete_CkStringBuilder $sbPath
delete_CkStringBuilder $sbJsonResponse
delete_CkJsonObject $json
delete_CkBinData $pngData