Add data communication for DataProvider for Collections

After this patch, the object is passed to the client-side as a
JsonObject containing a key "k" with value from object.toString()

Change-Id: I3f83144a6c84dda9812739ff2f2cb74cb5577d5c

1 files changed, 87 insertions, 12 deletions

diff --git a/server/src/com/vaadin/server/communication/data/typed/DataProvider.java b/server/src/com/vaadin/server/communication/data/typed/DataProvider.java
index 13755a5ce8..62d39d50ec 100644
--- a/server/src/com/vaadin/server/communication/data/typed/DataProvider.java
+++ b/server/src/com/vaadin/server/communication/data/typed/DataProvider.java
@@ -18,10 +18,13 @@ package com.vaadin.server.communication.data.typed;
 import java.util.Collection;
 
 import com.vaadin.server.AbstractExtension;
+import com.vaadin.shared.data.DataProviderClientRpc;
 import com.vaadin.shared.data.DataRequestRpc;
 import com.vaadin.ui.AbstractComponent;
 
+import elemental.json.Json;
 import elemental.json.JsonArray;
+import elemental.json.JsonObject;
 
 /**
  * DataProvider for Collection "container".
@@ -30,6 +33,27 @@ import elemental.json.JsonArray;
  */
 public class DataProvider<T> extends AbstractExtension {
 
+    /**
+     * Simple implementation of collection data provider communication. All data
+     * is sent by server automatically and no data is requested by client.
+     */
+    protected class DataRequestRpcImpl implements DataRequestRpc {
+
+        @Override
+        public void requestRows(int firstRowIndex, int numberOfRows,
+                int firstCachedRowIndex, int cacheSize) {
+            throw new UnsupportedOperationException(
+                    "Collection data provider sends all data from server."
+                            + " It does not expect client to request anything.");
+        }
+
+        @Override
+        public void dropRows(JsonArray rowKeys) {
+            // FIXME: What should I do with these?
+        }
+
+    }
+
     private Collection<T> data;
 
     /**
@@ -45,18 +69,69 @@ public class DataProvider<T> extends AbstractExtension {
         this.data = data;
         extend(component);
 
-        registerRpc(new DataRequestRpc() {
-            @Override
-            public void requestRows(int firstRowIndex, int numberOfRows,
-                    int firstCachedRowIndex, int cacheSize) {
-                throw new UnsupportedOperationException("Not implemented");
-            }
-
-            @Override
-            public void dropRows(JsonArray rowKeys) {
-                throw new UnsupportedOperationException("Not implemented");
-            }
-        });
+        registerRpc(createRpc());
+    }
+
+    /**
+     * Initially we need to push all the data to the client.
+     * 
+     * TODO: The same is true for unknown size changes.
+     */
+    @Override
+    public void beforeClientResponse(boolean initial) {
+        super.beforeClientResponse(initial);
+
+        if (initial) {
+            getRpcProxy(DataProviderClientRpc.class).resetSize(data.size());
+            pushRows(0, data);
+        }
+    }
+
+    /**
+     * Sends given row range to the client.
+     * 
+     * @param firstIndex
+     *            first index
+     * @param items
+     *            items to send as an iterable
+     */
+    protected void pushRows(long firstIndex, Iterable<T> items) {
+        JsonArray data = Json.createArray();
+
+        int i = 0;
+        for (T item : items) {
+            data.set(i++, getDataObject(item));
+        }
+
+        getRpcProxy(DataProviderClientRpc.class).setData(firstIndex, data);
+    }
+
+    /**
+     * Creates the JsonObject for given item. This method calls all data
+     * generators for this item.
+     * 
+     * @param item
+     *            item to be made into a json object
+     * @return json object representing the item
+     */
+    protected JsonObject getDataObject(T item) {
+        JsonObject dataObject = Json.createObject();
+
+        dataObject.put("k", item.toString());
+
+        // TODO: Add data generator stuff..
+
+        return dataObject;
+    }
+
+    /**
+     * Creates an instance of DataRequestRpc. By default it is
+     * {@link DataRequestRpcImpl}.
+     * 
+     * @return data request rpc implementation
+     */
+    protected DataRequestRpc createRpc() {
+        return new DataRequestRpcImpl();
     }
 
 }