Generate Data Matrix with Swift 2 and ZXingObjC - swift

Question

My problem is the following: I want to generate a data matrix with ZXingObjC and show it.
Currently i'm writing an application with XCode 7.3 and Swift 2.have to generate a data matrix with a String value. As the ZXingObjC written in Objective C, i tried to convert it myself according to this example:
NSError *error = nil;
ZXMultiFormatWriter *writer = [ZXMultiFormatWriter writer];
ZXBitMatrix* result = [writer encode:#"A string to encode"
format:kBarcodeFormatQRCode
width:500
height:500
error:&error];
if (result) {
CGImageRef image = [[ZXImage imageWithMatrix:result] cgimage];
} else {
NSString *errorMessage = [error localizedDescription];
}
The problem occurs when i try to encode my String with writer.encode(...) and i think it's good to precise that i tried with longer and smaller string but the result still the same.
do {
let writer = ZXMultiFormatWriter()
let hints = ZXEncodeHints() as ZXEncodeHints
let result = try writer.encode("foo", format: kBarcodeFormatDataMatrix, width: 300, height: 300, hints: hints)
let imageRef = ZXImage.init(matrix: result)
picture.image = UIImage(CGImage: imageRef.cgimage)
}
catch {
print(error)
}
And finally the app crash with this exception :
*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Can't find a symbol arrangement that matches the message. Data codewords: 17'
*** First throw call stack:
(
0 CoreFoundation 0x00000001081b7d85 __exceptionPreprocess + 165
1 libobjc.A.dylib 0x000000010854cdeb objc_exception_throw + 48
2 CoreFoundation 0x00000001081b7cbd +[NSException raise:format:] + 205
3 ZXingObjC 0x0000000107eb320a +[ZXDataMatrixSymbolInfo lookup:shape:minSize:maxSize:fail:] + 1178
4 ZXingObjC 0x0000000107ead4bb -[ZXDataMatrixEncoderContext updateSymbolInfoWithLength:] + 379
5 ZXingObjC 0x0000000107ea2866 -[ZXDataMatrixC40Encoder encode:] + 342
6 ZXingObjC 0x0000000107eaf032 +[ZXDataMatrixHighLevelEncoder encodeHighLevel:shape:minSize:maxSize:] + 1330
7 ZXingObjC 0x0000000107eb75b0 -[ZXDataMatrixWriter encode:format:width:height:hints:error:] + 672
8 ZXingObjC 0x0000000107ee246c -[ZXMultiFormatWriter encode:format:width:height:hints:error:] + 1100
9 DemoAppZXing 0x0000000103f54d98 _TFC4DemoAppZXing27VSMatrixOrderViewController11viewDidLoadfT_T_ + 8472
10 DemoAppZXing 0x0000000103f58002 _TToFC4DemoAppZXing27VSMatrixOrderViewController11viewDidLoadfT_T_ + 34
11 UIKit 0x0000000106a95984 -[UIViewController loadViewIfRequired] + 1198
12 UIKit 0x0000000106a9b93b -[UIViewController __viewWillAppear:] + 120
13 UIKit 0x0000000106acb750 -[UINavigationController _startCustomTransition:] + 1203
14 UIKit 0x0000000106adbb9b -[UINavigationController _startDeferredTransitionIfNeeded:] + 712
15 UIKit 0x0000000106adcd0b -[UINavigationController __viewWillLayoutSubviews] + 57
16 UIKit 0x0000000106c8b503 -[UILayoutContainerView layoutSubviews] + 248
17 UIKit 0x00000001069b5980 -[UIView(CALayerDelegate) layoutSublayersOfLayer:] + 703
18 QuartzCore 0x000000010a2bfc00 -[CALayer layoutSublayers] + 146
19 QuartzCore 0x000000010a2b408e _ZN2CA5Layer16layout_if_neededEPNS_11TransactionE + 366
20 QuartzCore 0x000000010a2b3f0c _ZN2CA5Layer28layout_and_display_if_neededEPNS_11TransactionE + 24
21 QuartzCore 0x000000010a2a83c9 _ZN2CA7Context18commit_transactionEPNS_11TransactionE + 277
22 QuartzCore 0x000000010a2d6086 _ZN2CA11Transaction6commitEv + 486
23 UIKit 0x00000001068f572e _UIApplicationHandleEventQueue + 7135
24 CoreFoundation 0x00000001080dd301 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17
25 CoreFoundation 0x00000001080d322c __CFRunLoopDoSources0 + 556
26 CoreFoundation 0x00000001080d26e3 __CFRunLoopRun + 867
27 CoreFoundation 0x00000001080d20f8 CFRunLoopRunSpecific + 488
28 GraphicsServices 0x000000010a8a1ad2 GSEventRunModal + 161
29 UIKit 0x00000001068faf09 UIApplicationMain + 171
30 DemoAppZXing 0x0000000103f60ec2 main + 114
31 libdyld.dylib 0x000000010905492d start + 1
)
libc++abi
.dylib: terminating with uncaught exception of type NSException
Edit :
To solve this problem, i just need to set the minSize and the maxSize.
let hints = ZXEncodeHints() as ZXEncodeHints
hints.maxSize = ZXDimension.init(width: 1000, height: 1000)
hints.minSize = ZXDimension.init(width: 1, height: 1)
let result = try writer.encode(generatedStr[0], format: kBarcodeFormatDataMatrix, width: 500, height: 500, hints: hints)

Answer 1

The method for returning the UIImage in the final form you need:
func generateDataMatrixQRCode(from string: String) -> UIImage? {
do {
let writer = ZXMultiFormatWriter()
let hints = ZXEncodeHints() as ZXEncodeHints
let result = try writer.encode(string, format: kBarcodeFormatDataMatrix, width: 1000, height: 1000, hints: hints)
if let imageRef = ZXImage.init(matrix: result) {
if let image = imageRef.cgimage {
return UIImage.init(cgImage: image)
}
}
}
catch {
print(error)
}
return nil
}

Answer 2

I think thats a "generic error" not tied to Swift but rather Zebra Crossing/ZXing. Try making the rect bigger, might help.
let result = try writer.encode("foo", format: kBarcodeFormatDataMatrix, width: 1000, height: 1000, hints: hints)