doc: Commands tests use `test_frontend`

[nit.git] / lib / app / data_store.nit

diff --git a/lib/app/data_store.nit b/lib/app/data_store.nit
index 5c59036..cb5ce2a 100644 (file)
--- a/lib/app/data_store.nit
+++ b/lib/app/data_store.nit
@@ -14,26 +14,76 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-# Simple data storage services
+# Key/value storage services
 #
-# The implementation varies per platform.
+# The main services is `App::data_store`, a `DataStore` holding any
+# serializable Nit object.
 module data_store
 
 import app_base
 import serialization
 
 # Platform variations
-# TODO: move on the platform once qualified names are understand in the condition
 import linux::data_store is conditional(linux)
 import android::data_store is conditional(android)
+import ios::data_store is conditional(ios)
 
 redef class App
+
        # Services to store and load data
-       fun data_store: DataStore is abstract
+       #
+       # ~~~
+       # import app::ui
+       # import app::data_store
+       #
+       # class MyWindow
+       #     super Window
+       #
+       #     var state = "Simple string or any serializable class"
+       #
+       #     redef fun on_save_state do app.data_store["state"] = state
+       #
+       #     redef fun on_restore_state
+       #     do
+       #         var state = app.data_store["state"]
+       #         if state isa String then self.state = state
+       #     end
+       # end
+       # ~~~
+       var data_store = new DataStore is lazy
 end
 
 # Simple data storage facility
-interface DataStore
+#
+# Write values with `[]=` and read with `[]`.
+# ~~~
+# import linux::data_store # Needed for testing only
+#
+# class A
+#     serialize
+#
+#     var b = true
+#     var f = 1.234
+# end
+#
+# var data_store = new DataStore
+# data_store["one"] = 1
+# data_store["str"] = "Some string"
+# data_store["a"] = new A
+#
+# assert data_store["one"] == 1
+# assert data_store["str"] == "Some string"
+# assert data_store["a"].as(A).b
+# assert data_store["a"].as(A).f == 1.234
+# assert data_store["other"] == null
+# ~~~
+#
+# Set to `null` to clear a value.
+# ~~~
+# data_store["one"] = null
+# assert data_store["one"] == null
+# ~~~
+class DataStore
 
        # Get the object stored at `key`, or null if nothing is available
        fun [](key: String): nullable Object is abstract