I am developing a Shiny App for data storage and I have to upload repeated measures of some patients. So I can have a new patient, where I will need to add his medical history data and also some variables of interest (like BMI, systolic pressure, etc), or patients already known, where the medical history is the same, and whats new is those variables of interest, measured weekly.
What I want to do is to have the possibility to have an ID for each patient, so I won't have to upload all his medical history each time a new measure is done, and for those new patients, have the possibility to upload his medical history once, and get it saved somewhere, so the next time I have new data of that patient just have to put that ID and have the medical history already uploadead.
I don't know if this kind of "memory" in a Shiny App si possible, any help?
A Shiny app (or any kind of web app for that matter) is not meant to be used as data storage per se, a Shiny app is great to be used as a user interface for storing data into a database, but the database has to be implemented separately and then integrated with your shiny app.
In my opinion, the ideal solution for this kind of application is a relational database, there are many options for implementing a Relational Database Management System (RDBMS) with different levels of complexity and functionalities but this is too broad of a topic. I think you should research a little bit into this possibility and come back with more concrete questions.
Also, I'm assuming this is some kind of learning effort and not a real life application, otherwise, be aware that when dealing with medical data you must be sure to comply with any legal requirements that might be applicable in your country since it is sensible information.