Installation:

Cinic is a Pharo library that aims to help managing external configuration files.
It can be loaded into a pharo image with:

Metacello new
    	repository: 'https://github.com/zweidenker/Cinic:0.3’;
    	baseline: 'Cinic';
    	load

While the model of Cinic is format-agnostic,
the current implemented parser expects a configuration to comes in the form of a JSON file.
The parser could later be extended to other formats if needed.

Here is a contents example of such a configuration file:

{ 
	“section1” :
		{
			“property1” :  “value1” 
		} ,
	“section2” :
		{
			“section21” :
				{
					“property2” : “value2”
				{			
		}
}

Loading configuration files:

A configuration file can be loaded by executing:

config := Cinic readFileNamed: 'config.json'.

The resulting Cinic object will be the entry point for traversing the imported configuration.

Model:

Cinic models configuration as a tree of Sections.
The root Section represents the root of the configuration file.
Sections can be nested without limitations.

Regarding the implementation, a Section object is nothing more than a specialised Dictionary object.
Its keys are property or section names,
Its values are property values or Section objects.

Scripting actions:

In order to act upon a configuration, Cinic provides some scripting facilities.
After loading the above configuration example, one could excecute:

#section1 sectionIn: config do: [ :aSection |
	Transcript show: aSection property1
	].
#section2 sectionIn: config do: [ :aSection |
	#section21 sectionIn: aSection do: [:aNestedSection |
		Transcript show: aSection property2
		]
	].

Note that property names can be turned into messages send to a Section object.
Cinic will automatically "translate" such unknown messages, and made them return the associated property value.

When iterating over inner sections of a configuration, Cinic will store the current section in a dynamic variable.
The above script can then be simplified as:

#section2 sectionIn: config do: [ :aSection |
	#section21 sectionDo: [:aNestedSection |
		Transcript show: aSection property2
		]
	].

Implementing actions:

An alternative to scripting configuration actions is to implement them as method.
This may be useful if you want to share a common action behaviour between multiple kind of configurations.
This can be done by using Steps.

Steps definition

A Step knows about a Section path and an action block.
The action block is expected to be executed with an associated Section object as argument:

CinicStep new
			section: #section1;
			action: [ :aSection1 | Transcript show: aSection1 property1 ].

A Step is intended to be returned by methods providing a <cinicStep> pragma:

section21SetUp
		<cinicStep>
    ^ CinicStep new
			  section: #section21;
			  action: [ :aSection21 | Transcript show: aSection property2 ].

Steps execution

After loading a configuration, one can execute the Steps associated to this configuration by executing .

config := Cinic readFileNamed: 'config.json'.
config apply.

When applying a configuration, Cinic will gather all methods in the pharo image with pragma <cinicStep>.
It will select the steps matching a section path in the configuration, and execute them.

The steps will be executed in the same order than the file sections order.

Steps section path

The above example shows the case of a "standalone" section: #section21.
As soon as a configuration file includes a section with name #section21, the Step will be executed.
But a Step could also target a more precise section path:

section1SetUp
		<cinicStep>
    ^ CinicStep new
			  sectionPath: #(section2 section21);
			  action: [ :aSection21 | Transcript show: aSection property1 ].

In this case, the Step would be executed only if the configuration file provide a section with name #section2,
followed by a section with name #section21.
The block would be evaluated with the #section21 associated object.

Global use:

After being loaded, a configuration can also be made globally available in the Pharo image with:

config beDefault

Code can then access

Cinic default