confused. I have a front end where i m creating some objects to save. After created those object, i Need First to check if they're already exist (back end call). How can i do to not lose those object withous sending them to the back end and then re-send to the front end After the check?
checksums?
Ajax
But I don't understand what are you trying to achieve by "check if they're already exist". I would just do one call always, just send objects and let backend decide whether they already exist and whether they should be stored, whatever. Basically, it's possible to have race condition between those two calls from frontend. That's why I would avoid doing something similar to what you've described.
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