Validate user input

[benstadlbauer]

The user input should be validated such that the database-entries are making sense and further statistics can be calculated in the future.

Description

This will be just a normal string.

Amount

This should be a valid amount format. Here, only positive numbers with a maximum of 2 decimal places should be allowed. The decimal separator could be a period . or a comma ,.

Date

Here, the user should choose from the browser-built-in calendar so no validation should be necessary.

Category

The user should choose a provided category so no validation should be necessary.