JSON_generator

How to Use the Data Model

The JSON data model its compose by

• JSONObject
• JSONArray
• JSONString
• JSONNumber
• JSONBoolean
• JSONNull

All of these derive from JSONValue. The JSONObject model uses JSONKey to represent the keys. This model is then used to instantiate data classes, collections, maps, primitive types, strings and enums.

Serialize Data

1. Create a PrintJSONVisitor

val v = PrintJSONVisitor()

2. Instanciate the data

a. Manually

val obj1 = JSONObject(hashMapOf(JSONKey("second") to arr1, JSONKey("tier2") to JSONString("Kappa"), JSONKey("thirdin") to JSONNull()))
obj1.accept(v)

b. Using supported reflection with JSONGenerator, calling the method instantiate passing the data as an argument.

val p1 = Point(2.0, 2.0, null, Form.Circle)

val jg = JSONGenerator()
val ee = jg.instantiate(p1)
ee.accept(v)

JSONGenerator also supports some annotations, these are:

• @Exclude - skip unwated properties (In the example below the name will not be instantiated
• @ChangeName(val newName: String) - change the name of a property (In the example below the Form will be instantiated with the name "geometry" instead of "form"

Example:

    data class Point(val x: Double, val y: Double,
                    @Exclude val name: String?,
                    @ChangeName("geometry") val form: Form
                       )

3. Print the data

To print the JSON it is only needed to access the output variable from visitor.

println(v.output)

How to Work with the UI

UI supports plugins for Icon Setups and Actions. These are easily implemented using the interfaces and adding the corresponding implementation to the di.properties file.

Icons

This library only supports one icon setup at a time.

interface IconSetup {

   fun getText(value : JSONValue): String
   fun getPath(value: JSONValue): String
   fun getIconWidth(value: JSONValue): Int
   fun getIconHeight(value: JSONValue): Int
   fun toExclude(value: JSONValue): Boolean = false
}

• getText method allows naming according to the JSONValue
• getPath method allows to pass the path to the icon image according to the JSONValue
• getIconWidthand getIconHeight gives the user the freedom to choose the icon size to each JSONValue
• toExcludemethod allows the user to exclude some JSONValues - not mandatory, default as false, meaning that it does not exclude anything

An example of an implementation is here

Actions

interface Action {
   val name: String
   fun execute(treeItem: TreeItem)
}

• name is the name of the button that will be created for the action.
• execute is the method that executes the action when the respective button is clicked.

There are three examples implemented:

• ValidateNumbers - checks if all JSONNumbers are positive.
• EditTreeItem - edits the name of the selected item.
• SaveToFile - saves the selected item to a JSON file.

Properties file

If no plugins are supplied in the di.properties file, the library still works as expected in the simplest form.

Visualizer.icons=ui.IconSetups.DefaultIconSetup
Visualizer.actions=ui.Actions.EditTreeItem,ui.Actions.SaveToFile,ui.Actions.ValidateNumbers