yunakai-terminal | Stripe Developers | Page 1

sacred portal Jun 7, 2022, 9:13 AM

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Hi there! Posting your message in this thread:

I didn't notice you moved from IRC to discord
last Friday I posted a tech question there but no one answered and I was wondering why, lol
anyway, like I said in there
I am in the process of integrating Stripe Terminal (on top of our current Stripe integration)
I think I could manage to get it all done but I had a doubt about how to handle terminal connections

tardy furnace Jun 7, 2022, 9:13 AM

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hi Soma!

sacred portal Jun 7, 2022, 9:14 AM

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I didn't notice you moved from IRC to discord
That happened a couple of years ago I think. We no longer actively monitor IRC, but now you are in the right place 🙂

tardy furnace Jun 7, 2022, 9:14 AM

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yea, my bad

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I didn't see the notification

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anyway, let me put you in context

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our scenario is basically a webpos so every time the page is loaded we initialize the whole POS

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this means the terminal discovery and whatnot

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so originally right after I get the terminal discovered I opened a connection and kept it alive during the whole session, which could mean that several transactions may happen

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but after some thinking I came to the conclusion that I should open a connection to the terminal only every time Stripe is being selected as a payment method

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meaning, I keep the discovered terminal all the time but open/close connections per transaction

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I wonder if this is an expected flow and a best practice

sacred portal Jun 7, 2022, 9:21 AM

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are you using the JavaScript SDK? And which Terminal reader are you using?

tardy furnace Jun 7, 2022, 9:22 AM

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correct, I'm using js sdk

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currently I'm using the sim, however I should get the physical terminal soon

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like today or tomorrow

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sec, I forgot the model I got

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BBPOS WisePOS

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which, from my understanding, supports js sdk

sacred portal Jun 7, 2022, 9:26 AM

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thanks for the information, let me look into this.

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after discussing with a colleague, we believe both options should work fine!

it’s fine to cache/ ‘hold onto’ the discovered reader like that. It would only stop working if something changes like the reader getting a new IP address or falling off the network or being turned off, at which point you have to discover again.
it’s also fine to connect once-per-transaction instead of connecting one and doing multiple transactions, I really don’t think it makes any difference, except maybe being a bit slower

tardy furnace Jun 7, 2022, 9:32 AM

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if you don't mind I'll post some js code so you can see more or less what I mean

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else if (this._mode === "terminal") {
if (_this._debug) {
console.debug("Stripe in terminal mode");
}
this._terminal = StripeTerminal.create({
onFetchConnectionToken: _this.fetchConnectionToken,
onUnexpectedReaderDisconnect: _this.unexpectedDisconnect
});
this.discoverTerminalReader();
if (_this._isValidHook(_this.stripePostinitHook)) {
_this.stripePostinitHook(_this);
}
if (_this._debug) {
_this._terminal.setSimulatorConfiguration({testCardNumber: '4242424242424242'});
}

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this is basically the init method I use in our custom Stripe object when the page loads

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whereas discoverTerminalReader looks like this:
this.discoverTerminalReader = function() {
var config = {};
if (_this._debug) {
config.simulated = true;
}
return _this._terminal.discoverReaders(config).then(function(discoverResult) {
if (discoverResult.error) {
console.log('Failed to discover: ', discoverResult.error);
return false;
} else if (discoverResult.discoveredReaders.length === 0) {
console.log('No available readers.');
return false;
} else {
// Just select the first reader here.
_this.terminalReader = discoverResult.discoveredReaders[0];
return true;
}
});
};

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so any time the user selects card payment (Stripe) I make the connection

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then disconnect if successful

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what I noticed doing the other way around (keeping the connection alive)

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is several requests stuck or taking so much time in the background

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it didn't have any impact regarding performance, at least locally while testing

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but it feels better to connect/disconnect

sacred portal Jun 7, 2022, 9:40 AM

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thanks for sharing the code! but like I said earlier both option should work.

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is several requests stuck or taking so much time in the background
can you share more details about this?

tardy furnace Jun 7, 2022, 9:46 AM

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unfortunately I can't I think, I made the changes already so now it behaves differently

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