Dynamic Functions and Templates for spiff

mandelsoft commented 8 years ago

This pull request adds two major features to spiff:

Dynamic functions The value of a dynaml expression might now be a function value described by a lambda expression. This function can then be called in any other dynaml expression by passing an approriate number of arguments in addition to the standard builtin functions. As new kind of values for the yaml document, they can be assigned to other properties and merged among multiple merge stubs.
Templates Templates are yaml fragments (parts of the reqular yaml file) that are explicitly tagged. They may contain dynaml expressions that will not be evaluated at its definition location. Using a dedicated reference expression they can be evaluated in the context of any dynaml expession. The contained references will be resolved in this context, so relative element paths are evaluated relative to the using element. Additionally they can be combined with dynaml functions by supporting the function parameter names as additional binding context. This way it is possible to provide functions returning complex structures supporting dynaml expressions for its values refering to function arguments.

Besides these major features there are several supporting features:

the programming of function makes sense only if there is a way to react on conditions. Therefore dynaml has been extended to support logical (-or/-and), comparison (==,<=,>=,>,<,!=,!), and conditional (?:) operators.
to work with deep structures chaining of expressions, function calls and references is possible now (.foo.bar(alice,bob).property)
lots of additional builtin functions have been added
- eval: reevaluate a string as dynaml expression to support access to composed attribute paths.
- env: to access environment variables
- format: to format strings based on arguments (GO Sprint function)
- length: length of strings, maps and lists
- num_ip: number of IPs in a CIDR
- split: split a string
- trim: removeleading and trailing white spaces (or other characters)

There are lots of examples in the documentation.

cfdreddbot commented 8 years ago

Hey mandelsoft!

Thanks for submitting this pull request! I'm here to inform the recipients of the pull request that you've already signed the CLA.

cf-gitbot commented 8 years ago

We have created an issue in Pivotal Tracker to manage this. You can view the current status of your issue at: https://www.pivotaltracker.com/story/show/113372421.

Amit-PivotalLabs commented 8 years ago

Hi @mandelsoft

As we've discussed, we do not wish to accept new functional PRs at this time. Due to the amount of effort in your first PR, we wanted to give you feedback and accept it, but as we've tried to re-iterate, we do not want to continue to accept functional PRs. I'm sorry but we will need to hold the presses on this one.

Best, Amit

mandelsoft commented 8 years ago

Hi Amit,

sorry, but I had to try to place this pull request. The first chunk only contained the stuff that caused problems in our today’s manifest generation. This one now is the last chunk of functionality required to do some fancy manifest generation for multi platform deployments. It rounds up the first one and fills some functional gaps.

I'm still convinced that spiff is a cool tool best suited to do this job. And I didn't found something comparable. The upcoming new features in bosh are still far away from replacing this manifest magic. Spiff has a large potential and it would be worth the effort extending it. It's really too bad, that it is discontinued.

If the problem are your shifting priorities, and you don’t have enough time to handle pull requests, I could offer to support you in handling future pull-requests (if any).

Nevertheless, thank you very much for your support on the first pull request.

Uwe

From: Amit Gupta [mailto:notifications@github.com] Sent: Dienstag, 9. Februar 2016 18:24 To: cloudfoundry-incubator/spiff spiff@noreply.github.com Cc: Krueger, Uwe uwe.krueger@sap.com Subject: Re: [spiff] Dynamic Functions and Templates for spiff (#73)

Hi @mandelsofthttps://github.com/mandelsoft

As we've discussed, we do not wish to accept new functional PRs at this time. Due to the amount of effort in your first PR, we wanted to give you feedback and accept it, but as we've tried to re-iterate, we do not want to continue to accept functional PRs. I'm sorry but we will need to hold the presses on this one.

Best, Amit

— Reply to this email directly or view it on GitHubhttps://github.com/cloudfoundry-incubator/spiff/pull/73#issuecomment-181967301.

cloudfoundry-incubator / spiff

Dynamic Functions and Templates for spiff #73