Problem with Javascript function

[zahaiak]

Hi
Can you help me with this JavaScript function. It has 5 parameters input and one out put.
function getbase64(name, taxNumber, date, total, vat) {
const tags = [
{ index: 1, value: name },
{ index: 2, value: taxNumber },
{ index: 3, value: date },
{ index: 4, value: total },
{ index: 5, value: vat },
];
const toHex = (value) => {
let hex = value.toString(16);
if (hex.length % 2 > 0) {
hex = "0" + hex;
}
return Buffer.from(hex, "hex").toString("utf-8");
};
const tlv = tags
.map(
(tag) =>
toHex(tag.index) + toHex(Buffer.byteLength(tag.value)) + tag.value
)
.join("");
return Buffer.from(tlv).toString("base64");
}
//Example
const name = "Zuhair";
const taxNumber = "1234567891";
const date = "2021-12-04T00:00:00Z";
const total = "100.00";
const vat = "15.00";

console.log(getbase64(name, taxNumber, date, total, vat));

Please help me with that.

Thanks,

[TIMAI2]

Please show your relevant blocks

[zahaiak]

[marco_tanzi]

Your iussue Is // Example.

stripping lines javascript doesn't recognize the rest of the code.

Regards @marco_tanzi

[TIMAI2]

Why the double quotes here: getBase64(" and here: ")); ? All your variables are already quoted ....

[edit] - quotes are required

[Juan_Antonio]

I think:

Uncaught ReferenceError: Buffer is not defined

Try your code in:
https://jsfiddle.net/

function getbase64(name, taxNumber, date, total, vat) {
const tags = [
{ index: 1, value: name },
{ index: 2, value: taxNumber },
{ index: 3, value: date },
{ index: 4, value: total },
{ index: 5, value: vat },
];
const toHex = (value) => {
let hex = value.toString(16);
if (hex.length % 2 > 0) {
hex = "0" + hex;
}
return Buffer.from(hex, "hex").toString("utf-8");
};
const tlv = tags
.map(
(tag) =>
toHex(tag.index) + toHex(Buffer.byteLength(tag.value)) + tag.value
)
.join("");
return Buffer.from(tlv).toString("base64");
}

const name = "Zuhair";
const taxNumber = "1234567891";
const date = "2021-12-04T00:00:00Z";
const total = "100.00";
const vat = "15.00";

console.log(getbase64(name, taxNumber, date, total, vat));

[Joerg_Kowalski]

@zahaiak Look at this:

You have to decide whether a variable is of type string or number or else;

the following makes it clear: it works:

doesn't work if "x" is of type "string"

x of type number works:

numbers as string work (there must be an internal conversion to data type "number", I guess)

[zahaiak]

Thanks guys
I think I have to fix the JavaScript function first
I'm not sure if it work or not.

Thanks again

[Joerg_Kowalski]

@zahaiak I don't think so. The JavaScript function looks good (change //Example to /star Example star/). It's more a problem of passing the variables right way coming from inside AppInventor.

[TIMAI2]

Perhaps this script may be a little easier to use?

	function getbase64(name, taxNumber, date, total, vat) {
	var el = [name, taxNumber, date, total, vat];
	var base64 = []; 
	for (var i=0;i<el.length;i++) {
		base64.push(btoa(el[i]));
	}
    return base64.toString();
    }

[Juan_Antonio]

Script of @TIMAI2 in https://jsfiddle.net/

- btoa

- atob

[Edited]

[TIMAI2]

in blocks, seems to work

Double quotes are needed around strings, use number blocks for ...numbers.

window.AppInventor.setWebViewString(getbase64("TimAi2",1234567,"21-12-2021",147.24,14.7));

[zahaiak]

Thanks for your help but it doesn't work with me. Could you please give me your aia file.

[TIMAI2]

Here you are
jsTest.aia (2.4 KB)

[zahaiak]

Thanks,
But what I need is deferent. please look to the pictures.

[TIMAI2]

OK sorry, but hopefully my code will help you to get the syntax for your script working

[Joerg_Kowalski]

@zahaiak this works

testentesten.aia (4.1 KB)

in this example the label above shows the result: in this case "RESULT". Here you have only to adapt it to your app. I have written your function to a textBox that you can also use to test some JS code.

For example, change the return value to taxNumber (can be done in the textBox at runtime) - then you see the result in the label. You'll get taxNumber instead of "RESULT", one proof more that it works.

[Juan_Antonio]

With the idea of @TIMAI2 and this code, we can get closer to what you are looking for.

Borrar_Base64_C.aia (3.7 KB)

[Juan_Antonio]

Another version.

Borrar_Base64_D.aia (4.7 KB)

[zahaiak]

I'm so glad that you help me with this problem. You are done it so perfectly. However, Tags and Value Length should be hex number before covering them to Base 64. Please see the Hex Representation attached.