Getting ESCPOS commands instead of Uint8Array of bytes

[umutesen]

The encode appears to generate an Uint8Array array containing all the bytes. How can I generate ESC/POS commands instead of the byte array?

[bakrianoo]

I am searching for this feature too.

[bakrianoo]

@umutesen I found a solution which might help you
https://www.npmjs.com/package/jszpl

[waweru-kamau]

I found a small function to handle decoding Uint8Array:

function Utf8ArrayToStr(array) {
    var out, i, len, c;
    var char2, char3;

    out = "";
    len = array.length;
    i = 0;
    while(i < len) {
    c = array[i++];
    switch(c >> 4)
    { 
      case 0: case 1: case 2: case 3: case 4: case 5: case 6: case 7:
        // 0xxxxxxx
        out += String.fromCharCode(c);
        break;
      case 12: case 13:
        // 110x xxxx   10xx xxxx
        char2 = array[i++];
        out += String.fromCharCode(((c & 0x1F) << 6) | (char2 & 0x3F));
        break;
      case 14:
        // 1110 xxxx  10xx xxxx  10xx xxxx
        char2 = array[i++];
        char3 = array[i++];
        out += String.fromCharCode(((c & 0x0F) << 12) |
                       ((char2 & 0x3F) << 6) |
                       ((char3 & 0x3F) << 0));
        break;
    }
    }

    return out;
}

Source here

[alesrosina]

You could also do it a bit easier:

const escpos = new EscPosEncoder();

const printValue = escpos.initialize()
       .line('This is a test line')
       .encode();

// this is a string representation
const result = Buffer.from(printValue.buffer).toString();
      

If you are using this from browser, then I recomend also using tihs lib: https://github.com/feross/buffer