Programmatically build workflow

[ribeiromiranda]

Proposal for programmatically build workflow definitions.

Example:

workflowBuilder, builder := NewWorkflowBuilder("test", "1.0")
workflowBuilder.
  Function("function0", "http://...").
  Parent().
  Event("event0").
  Parent().
  OperationState("state0").Action("action0").FunctionRef("function0").
  Parent().
  Parent().
  Parent().
  OperationState("state1").Action("action0").FunctionRef("function0")

workflowBuilder.OperationState("state2").Action("action0").FunctionRef("function1")
workflowBuilder.Function("function1", "http://...")
workflow := builder.Build()

[ricardozanini]

Great improvement to the SDK! A few suggestions, if you don't mind!

[ricardozanini]

What about an interface instead? Hence, we can model different builders if needed and have a clear API.

Also, can we have a WorkflowBuilder.BuildAsYaml(path)? This way we can persist into a file programmatically. wdyt?

[ribeiromiranda]

The builder interface has been decoupled from the WorkflowBuilder, so it is possible to have an ActionBuilder

It is possible to do this as follows:

type Builder[T, K any] struct {
	builder Build[K]
}

func (b *Builder[T, K]) Build() K {
	return b.builder.Build()
}

func (b *Builder[T, K]) BuildAsYaml() string {
	return b.builder.BuildAsYaml()
}

type Build[T any] interface {
	Build() T
	BuildAsYaml() string
}

[ricardozanini]

Fair enough!

[ricardozanini]

Can you implement it in this PR? We may use our functions to generate the file.

[ricardozanini]

Can you implement it in this PR? We may use our functions to generate the file.

[spolti]

Very nice, just one thing, maybe improve the tests.

Added a small comment about it.

Other than that, just address the open Zanini's questions. :)

Thanks very much!

[spolti]

for the test, can you please improve it?

E.g., use a complete workflow that we have in the examples, build it using the Builder, then parse it to yaml or json and compare the final result with the example we have used as base.

does it make sense?

[spolti]

@ribeiromiranda hi, do you still have plans to continue working on this PR?

Thanks.

[ribeiromiranda]

@spolti I'm looking at creating a "builder-gen" as the "deepcopy-gen". But, I'm short on time.

[spolti]

Nice, no problem, take your time and many thanks!!!

[ribeiromiranda]

@ricardozanini @spolti Hi,

Generated the file model/zz_buildergen_generated.go with generator builder-gen.
In the file model/builder/builder_test.go there is an example of use.
Do you agree with this builder format?

Some pending issues detected:

• Support to type floatstr.Float32OrString
• Support to type Object
• Support to type Map
• Execute validation

Generator used:
https://github.com/galgotech/gengo/blob/builder-gen/examples/builder-gen/generators/builder.go

[ricardozanini]

Pretty cool!

[ricardozanini]

@ribeiromiranda when you finish, can you let us know so we can do a final review/

[ribeiromiranda]

@ribeiromiranda when you finish, can you let us know so we can do a final review/

@ricardozanini I think for a first version is ready for review.

[ricardozanini]

LGTM

[ricardozanini]

Closes #154

I missed the CI from my notifications, merging it.