(Objective-C) 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 Objective-C Library Downloads MAC OS X (Cocoa) Libs iOS Libs

#import <CkoJsonObject.h>
#import <CkoStringBuilder.h>
#import <CkoRest.h>
#import <CkoBinData.h>

// 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)
CkoJsonObject *jsonToken = [[CkoJsonObject alloc] init];
[jsonToken LoadFile: @"qa_data/tokens/paypal.json"];

// Build the Authorization request header field value.
CkoStringBuilder *sbAuth = [[CkoStringBuilder alloc] init];
// token_type should be "Bearer"
[sbAuth Append: [jsonToken StringOf: @"token_type"]];
[sbAuth Append: @" "];
[sbAuth Append: [jsonToken StringOf: @"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.
CkoRest *rest = [[CkoRest alloc] init];
BOOL bAutoReconnect = YES;
BOOL success = [rest Connect: @"api.sandbox.paypal.com" port: [NSNumber numberWithInt: 443] tls: YES autoReconnect: bAutoReconnect];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

// ----------------------------------------------------------------------------------------------
// 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.
CkoStringBuilder *sbPath = [[CkoStringBuilder alloc] init];
[sbPath Append: @"/v1/invoicing/invoices/invoice_id/qr-code"];
int numReplacements = [[sbPath Replace: @"invoice_id" replacement: @"INV2-ZG2H-HKAW-PMWU-N6ZR"] intValue];

[rest AddHeader: @"Authorization" value: [sbAuth GetAsString]];
// A 500x500 image results in a PNG file of approx. 4K bytes in size.
[rest AddQueryParam: @"width" value: @"500"];
[rest AddQueryParam: @"height" value: @"500"];
[rest AddQueryParam: @"action" value: @"pay"];

// Send the GET request and get the PNG image data as base64.
// A successful JSON response looks like this:
// {"image":"iVBORw0KGgoAA....AASUVORK5CYII="}
CkoStringBuilder *sbJsonResponse = [[CkoStringBuilder alloc] init];
success = [rest FullRequestNoBodySb: @"GET" uriPath: [sbPath GetAsString] sb: sbJsonResponse];
if (success != YES) {
    NSLog(@"%@",rest.LastErrorText);
    return;
}

CkoJsonObject *json = [[CkoJsonObject alloc] init];
json.EmitCompact = NO;
[json LoadSb: sbJsonResponse];

NSLog(@"%@%d",@"Response Status Code = ",[rest.ResponseStatusCode intValue]);

// Did we get a 200 success response?
if ([rest.ResponseStatusCode intValue] != 200) {
    NSLog(@"%@",[json Emit]);
    NSLog(@"%@",@"Failed.");
    return;
}

// If the 200 response is received, the response body contains the PNG data.
// Save the PNG to a file.
CkoBinData *pngData = [[CkoBinData alloc] init];
[pngData AppendEncoded: [json StringOf: @"image"] encoding: @"base64"];
success = [pngData WriteFile: @"qa_output/paypal_qr_code.png"];
if (success == NO) {
    NSLog(@"%@",@"Failed to save PNG file.");
    return;
}

NSLog(@"%@",@"Success.");