How do I get to see the contents of a NSData array in JXA?

Question

I need to do some manipulation on a file byte array and as far as I have read, I cannot do this unless I use ObjectiveC bridging. This is what I have done for now:

var filepath = file.toString();
ObjC.import('stdlib');
ObjC.import('Foundation');

var theFileData = $.NSData.dataWithContentsOfFile(filepath);
var fileSize = theFileData.length;

If I try using $.malloc(filesize) it will say the function is undefined... how am I supposed to check the contents of theFileData ?

score 0 · Accepted Answer · answered Jul 28 '19 at 17:31

I have gone into this in-depth in the answer I posted to your other question, so please refer to that for more details.

But here you go:

function readBytes(filepath) {
    const bytes    = $.NSData.dataWithContentsOfFile(
                        $.NSString.stringWithString(filepath)
                         .stringByStandardizingPath);
    const bytesPtr = bytes.bytes;
    var   bytesArr = [];
    const numBytes = Number(bytes.length);

    for (let i = 0; i < numBytes; i++) {
        bytesArr.push(bytesPtr[i]);
    }

    return bytesArr;    
}

How do I get to see the contents of a NSData array in JXA?

1 Answers1