Enhance support for Application Properties

[vijaynalawade]

I'm submitting a ... (check one with "x")

[] bug report => search github for a similar issue or PR before submitting
[x] feature request
[] support request
[] general question

Current behavior (how does the issue manifest):
Currently, there is no support for property type or grouping of properties.
Expected behavior:
Users should be able to set a type as well able to group set of properties together.
Minimal steps to reproduce the problem (not required if feature enhancement):

What is the motivation / use case for changing the behavior?
https://github.com/TIBCOSoftware/flogo/wiki/Application-Properties
Please tell us about your environment (Operating system, docker version, browser & web ui version, etc):

Flogo version (CLI & contrib/lib. If unknown, leave empty or state unknown): 0.X.X

Additional information you deem important (e.g. issue happens only occasionally):

[retgits]

I like the idea! One small question though, in one of the code blocks you're referring to $env[ENV_DB_URL] while today that would be $env.ENV_DB_URL. Do we expect to change that too and if so, will it be backward compatible with the existing apps?

[vijaynalawade]

@retgits Thats proposed change for consistency with $property and $activity. Though supported for few releases, we will deprecate use of $env.<NAME> in the future.

[ayh20]

are you talking about deprecating $env completely ? or just the $env.ENV_VAR syntax ?

[mellistibco]

@ayh20 just changing the syntax. so we'll make the switch to $env[ENV_DB_URL] and support the syntax of $env.ENV_DB_URL and $env[ENV_DB_URL] for a period of time.

[mellistibco]

Resolved in TIBCOSoftware/flogo-lib#171