JarCastingPojson
Pojson is a kotlin library for json prototyping. It brings DSL for building JsonObjectPrototype and JsonArrayPrototype. Prototypes don't reference to any json object/array models. You can choose implementation you want to use for rendering json. Simple json prototype may looks like:
val prototype = JsonObjectPrototype {
"my-string-property" % "Hello, world!"
"my-number-property" % 42L
"my-object-property" % obj {
"my-nested-object-property" % true
}
"my-array-property" % array {
element("Hello, world!")
element(42L)
element(true)
}
}
Usage
Actually Pojson is a kotlin class with methods render for object and array.
val prototype = JsonObjectPrototype {
..
}
val pojson = Pojson(..)
pojson.render(prototype) // Returns selected json object representation
Pojson constructor requires implementation of interfaces JsonObjectFactory, JsonArrayFactory, JsonObjectAdapter, JsonArrayAdapter. Usually implementation of this interfaces is a simple task. You can implement this interfaces manually or use one of existing integration with json object/array representation.
val prototype = JsonObjectPrototype {
..
}
Pojson2Gson.create().render(prototype) // Returns com.google.gson.JsonObject
Pojson2NativeJSON.create().render(prototype) // Returns org.json.JSONObject
Pojson2NativeCollection.create().render(prototype) // Returns java.util.Map
Syntax
Create object
Pojson provides class JsonObjectPrototype with constructor as entry point for object notation.
JsonObjectPrototype {
..
}
Assign property
Pojson provides overloaded operator % for assigning value to key in object notation.
JsonObjectPrototype {
"my-property" % "my-value"
}
Create array
Pojson provides class JsonArrayPrototype with constructor as entry point for array notation.
JsonArrayPrototype {
..
}
Append element
Pojson provides element(..) method for appending items to array.
JsonArrayPrototype {
element(42L)
element("Hello, world!")
}
Nested object
Pojson provides method obj { .. } for nested object instantiation.
JsonObjectPrototype {
"my-property" % obj {
"my-nested-property" % "my-nested-value"
}
}
Nested array
Pojson provides method array { .. } for nested array instantiation.
JsonObjectPrototype {
"my-property" % array {
..
}
}
Nullability
By default pojson requires all values to be non-null. If you want to work with nullable values you should specify it explicitly. Pojson provides method nullable for this purpose.
val myString: String? = "Hello, world!"
// Not working
JsonObjectPrototype {
"my-property" % myString // IDE error: expected [String] but found [String?]
}
// Working
JsonObjectPrototype {
"my-property" % nullable(myString) // No error, correct type inference
}
Also pojson provides utility methods nullString, nullNumber, nullBoolean, nullObject and nullArray
for kotlin type inference when you want to use if-else expressions inside object/array notation.
JsonObjectPrototype {
"my-property" % if (myFlag) obj {
..
} else nullObject()
}
Composition
Pojson provides capability to composite prototypes.
val manufacturer = JsonObjectPrototype {
"name" % "Land Rover"
"country" % "United Kingdom"
}
val car = JsonObjectPrototype {
"model" % "Defender"
"year" % 2017
"manufacturer" % manufacturer
}
Merge
Pojson provides capability to merge prototype properties into another prototype.
val design = JsonObjectPrototype {
"color" % "black"
"wheels" % "20.0 inch"
}
val car = JsonObjectPrototype {
"model" % "Defender"
"year" % 2017
merge(design)
}
Integration
Core
Core module contains syntax declaration without integrations with third-party solutions.
dependencies {
implementation 'io.github.acelost:pojson-core:${latestVersion}'
}
Gson
Gson module contains syntax declaration plus integration with gson object model. You can render prototypes to com.google.gson.JsonObject and com.google.gson.JsonArray.
dependencies {
implementation 'io.github.acelost:pojson-gson:${latestVersion}'
}
Native Json
Native Json module contains syntax declaration plus integration with native android object model. You can render prototypes to org.json.JSONObject and org.json.JSONArray.
dependencies {
implementation 'io.github.acelost:pojson-native-json:${latestVersion}'
}
Native Collection
Native Collection module contains syntax declaration plus integration with native java collections. You can render prototypes to java.util.Map and java.util.List.
dependencies {
implementation 'io.github.acelost:pojson-native-collection:${latestVersion}'
}