Get notified when price changes?

[andyderuyter]

First of: Love this project. A lot. Thank you!

I was wondering if something like this was possible:

While item amount is not zero, check if item price is changing. I live in Belgium and we have something called 'Dynamic Price' where a shop can adjust the price. Some prices start really high and only get interesting when they are lower of course.

[xusheng-gao]

just go make the change yourself, feel free to submit a PR. basically in addition to checking for item count, check for price or value change based on the previous state: https://github.com/Der-Henning/tgtg/blob/main/tgtg_scanner/scanner.py#L146

something like state_item.price != item.price or state_item.value != item.price should do it

[Pavlo-Kk]

@andyderuyter I adjusted def _check_item in the following way, and now I also receive notifications when the price is being changed.
https://github.com/Der-Henning/tgtg/blob/main/tgtg_scanner/scanner.py#L134

    def _check_item(self, item: Item) -> None:
        """Checks if the available item amount raised from zero to something or price changed
        and triggers notifications.
        """
        state_item = self.state.get(item.item_id)
        if state_item is not None:
            if state_item.items_available == item.items_available and state_item.price == item.price:
                return
            if state_item.items_available != item.items_available:
                log.info("%s - amount changed from %s to %s", item.display_name, state_item.items_available, item.items_available)
            if state_item.items_available == 0 and item.items_available > 0:
                self._send_messages(item)
                self.metrics.send_notifications.labels(item.item_id, item.display_name).inc()
            if state_item.items_available > 0 and item.items_available > 0 and state_item.price != item.price:
                log.info("%s - price changed from %s to %s", item.display_name, state_item.price, item.price)
                self._send_messages(item)
                self.metrics.send_notifications.labels(item.item_id, item.display_name).inc()
        self.metrics.update(item)
        self.state[item.item_id] = item

It would be even more convenient if the notification included details about the trigger type (e.g., whether it’s due to a new amount or a changed price). However, implementing this seems to require significant changes, and I’m not fully confident in making such modifications myself.
It would be great if @Der-Henning could consider adding this functionality in one of the upcoming releases. 🙂

[fdelahuz]

This new price change notifications can be really interesting as some items in my area eventually get lower prices that make them more affordable.
I can see the console notification but don't understand if it is possible to forward this notification to the telegram bot chat and how the message body could be formatted as the "new item available" is.

[Pavlo-Kk]

I can see the console notification but don't understand if it is possible to forward this notification to the telegram bot chat and how the message body could be formatted as the "new item available" is.

Set
PriceMonitoring = true
in config.ini, or environment variable
PRICE_MONITORING = true
in your docker compose.

I also use custom TELEGRAM_BODY value
\n💰 $${{price}} \\(previous: $${{previous_price}}\\)\n

[andyderuyter]

I have a 'hackish' way to differntiate between a new magic bag and a price change:

main...andyderuyter:tgtg:reason-icons

Maybe @Pavlo-Kk can work something more elegant into his code? I wanted a way to see what sort of notification was sent.

[Pavlo-Kk]

@andyderuyter for us custom message body (that includes old and new prices) already works very well.

[andyderuyter]

@Pavlo-Kk In case of new stock, is the 'old price' the same as current price?

[fdelahuz]

Thanks, custom telegram bot message body with old and new prices works for me also, when new item available is found.
This message is sent when I get "Sending notifications for... - x bags available" on my console output as stock has increased from 0 to something.
But previously to this message there are another ones only visibles on my console output "xxx name of item xxx - price changed from x,xx €s to x,xx €" (but without amount of bags availables) that I was wondering if it is possible to be forwarded to the telegram bot or not, so I can expect the next item to be cheaper than usual and get as ready as possible to pick it up.

[Pavlo-Kk]

@Pavlo-Kk In case of new stock, is the 'old price' the same as current price?

Either the same as the current price, or sometimes None. So it is easy to see if the notification is about new items or the price change.

[Pavlo-Kk]

But previously to this message there are another ones only visibles on my console output "xxx name of item xxx - price changed from x,xx €s to x,xx €" (but without amount of bags availables) that I was wondering if it is possible to be forwarded to the telegram bot or not, so I can expect the next item to be cheaper than usual and get as ready as possible to pick it up.

Have you set PriceMonitoring/PRICE_MONITORING to true? It should activate sending of notification about the price change.

            if state_item.price != item.price:
                log.info("%s - price changed from %ss to %s", item.display_name, state_item.price, item.price)
                if self.config.price_monitoring and item.items_available > 0 and item._price < state_item._price:
                    send_notification = True
            if send_notification:
                self._send_messages(item)
                self.metrics.send_notifications.labels(item.item_id, item.display_name).inc()