[ovirt-devel] Custom Properties code duplication

[Lior Vernia]

Hello,

While adding network custom properties towards oVirt 3.5, I got to take
a good look at the custom properties code in the backend and frontend.
It seems to me like there's a lot of code duplication, and I would like
to suggest the following refactoring:

1. Remove dependencies on Pattern/Matcher and ApacheCommons methods from
*CustomPropertiesUtils.java, to make them compilable with GWT, and move
these utilities to the common package. The usage of the said methods is
minimal and could easily be replaced with String methods, etc.

2. Modify KeyValueModel to delegate to the common utilities instead of
duplicating code, e.g. for validation.

3. Move some validation, which is relevant to all custom properties
(e.g. duplicate keys), from specific utils (e.g. VmPropertiesUtils) up
to the shared CustomPropertiesUtils.

4. Optionally change the implementation of custom properties members in
entities (e.g. VM) from String to Map<String, String>, which would
obviate the need for different conversion methods between String/Map -
(de)serialization would only be required in DB interaction.

The main argument against this would be that the frontend is to be moved
over the REST, and might not be written in Java much longer anyway.

However, to my understanding, there's some time until these changes take
effect. And even if the frontend is to be written in JavaScript, at
least initially the existing frontend code will have to still be used
somehow (e.g. auto-translated to JavaScript). That is to say, this
refactoring might still be beneficial for the not-so-short term.

Before going through with this, I wanted to ask for your thoughts and to
hear any specific objections to the proposed changes.

Yours, Lior.