Inline editor messes with the type of the edited value

[uap-universe]

Assume you have an object with number fields in it.

When you use this object as source for the smart table and enable inline editing, the following can be observed:

• when you edit a value, it will be overwritten with a new value of type string
• when you open the inline editor and immediately accept without making changes, the values will be left unchanged and keep their type

The consequence is that application code can never be sure what type the values actually have after editing.

The same is true btw. for null or undefined values. When you don't change anything, the original value remains untouched, keeping a possible null or undefined type. But if you touched the editor and for example entered some text and the remove the text again, the previous null value will be overwritten with an empty string.

So in other words: when the type of a column is T, the type of the data in a particular row (!) must be assumed as T | string. This is particularly relevant when you are doing some validation in the (confirmEdit) event handler.

[uap-universe]

We solve this the following way:

• Clean up valuePrepareFunction and filterFunction #117 already forces the valuePrepareFunction to produce strings
• we make the Cell to always use string internally
• we make the newValue of the Cell private s.t. a new value can only be set via a method
• we add an (optional) counter-part for the valuePrepareFunction to convert a string back to the actual type

Lacking a better name, we will call the new function valueStoreFunction.