Add assignment to set shouldObserve and isDependent keys.

Frameworks/D2W/ERModernDirectToWeb/Sources/er/modern/directtoweb/assignments/ERMDAjaxUpdateAssignment.java

@@ -0,0 +1,112 @@
+package er.modern.directtoweb.assignments;
+
+import com.webobjects.directtoweb.D2WContext;
+import com.webobjects.eocontrol.EOKeyValueUnarchiver;
+import com.webobjects.foundation.NSArray;
+import com.webobjects.foundation.NSDictionary;
+
+import er.directtoweb.assignments.ERDAssignment;
+import er.directtoweb.pages.ERD2WPage;
+import er.extensions.foundation.ERXArrayUtilities;
+import er.modern.directtoweb.components.ERMDAjaxNotificationCenter;
+
+/**
+ * Simple assignment that checks whether a property is to be observed for
+ * changes or is dependent on another property.
+ * 
+ * See {@link er.modern.directtoweb.components.ERMDAjaxNotificationCenter}
+ * 
+ * @d2wKey propertyDependencies
+ * @d2wKey propertyKey
+ * 
+ * @author fpeters
+ *
+ */
+public class ERMDAjaxUpdateAssignment extends ERDAssignment {
+
+    private static final long serialVersionUID = 1L;
+
+    /**
+     * Static constructor required by the EOKeyValueUnarchiver interface. If
+     * this isn't implemented then the default behavior is to construct the
+     * first super class that does implement this method. Very lame.
+     * 
+     * @param eokeyvalueunarchiver
+     *            to be unarchived
+     * @return decoded assignment of this class
+     */
+    public static Object decodeWithKeyValueUnarchiver(EOKeyValueUnarchiver eokeyvalueunarchiver) {
+        return new ERMDAjaxUpdateAssignment(eokeyvalueunarchiver);
+    }
+
+    /**
+     * Public constructor
+     * 
+     * @param u
+     *            key-value unarchiver used when unarchiving from rule files.
+     */
+    public ERMDAjaxUpdateAssignment(EOKeyValueUnarchiver u) {
+        super(u);
+    }
+
+    /**
+     * Public constructor
+     * 
+     * @param key
+     *            context key
+     * @param value
+     *            of the assignment
+     */
+    public ERMDAjaxUpdateAssignment(String key, Object value) {
+        super(key, value);
+    }
+
+    /**
+     * Implementation of the
+     * {@link er.directtoweb.assignments.ERDComputingAssignmentInterface}.
+     * 
+     * @return empty array.
+     */
+    @Override
+    public NSArray<String> dependentKeys(String keyPath) {
+        return new NSArray<String>(ERD2WPage.Keys.propertyKey,
+                ERMDAjaxNotificationCenter.PROPERTY_DEPENDENCIES.key());
+    }
+
+    /**
+     * Checks whether the current property is declared as to be observed via the
+     * propertyDependencies key.
+     * 
+     * @return true if the current property key is to be observed
+     */
+    public Object shouldObserve(D2WContext context) {
+        boolean shouldObserve = false;
+        NSDictionary<String, NSArray<String>> propertyDependencies = ERMDAjaxNotificationCenter.PROPERTY_DEPENDENCIES
+                .valueInObject(context);
+        if (propertyDependencies != null
+                && propertyDependencies.containsKey(context.propertyKey())) {
+            shouldObserve = true;
+        }
+        return shouldObserve;
+    }
+
+    /**
+     * Checks whether the current property is declared dependent via the
+     * propertyDependencies key.
+     * 
+     * @return true if the current property is dependent
+     */
+    public Object isDependent(D2WContext context) {
+        boolean isDependent = false;
+        NSDictionary<String, NSArray<String>> propertyDependencies = ERMDAjaxNotificationCenter.PROPERTY_DEPENDENCIES
+                .valueInObject(context);
+        if (propertyDependencies != null) {
+            if (ERXArrayUtilities.flatten(propertyDependencies.allValues()).contains(
+                    context.propertyKey())) {
+                isDependent = true;
+            }
+        }
+        return isDependent;
+    }
+
+}