Add scoped attribute getters with supplier

omnifaces · Sep 10, 2017 · 7d1bf0d · 7d1bf0d
1 parent 702fac4
commit 7d1bf0d
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diff --git a/src/main/java/org/omnifaces/util/Faces.java b/src/main/java/org/omnifaces/util/Faces.java
@@ -28,6 +28,7 @@
 import java.util.MissingResourceException;
 import java.util.ResourceBundle;
 import java.util.Set;
+import java.util.function.Supplier;
 
 import javax.el.ELContext;
 import javax.el.ELResolver;
@@ -2024,6 +2025,20 @@ public static <T> T getRequestAttribute(String name) {
 		return FacesLocal.getRequestAttribute(getContext(), name);
 	}
 
+	/**
+	 * Returns the request scope attribute value associated with the given name, or computes the supplied value if absent.
+	 * @param <T> The expected return type.
+	 * @param name The request scope attribute name.
+	 * @param computeIfAbsent The computed request scope attribute value when absent. Useful if it represents a collection, map or bean.
+	 * @return The request scope attribute value associated with the given name.
+	 * @throws ClassCastException When <code>T</code> is of wrong type.
+	 * @see ExternalContext#getRequestMap()
+	 * @since 3.0
+	 */
+	public static <T> T getRequestAttribute(String name, Supplier<T> computeIfAbsent) {
+		return FacesLocal.getRequestAttribute(getContext(), name, computeIfAbsent);
+	}
+
 	/**
 	 * Sets the request scope attribute value associated with the given name.
 	 * @param name The request scope attribute name.
@@ -2072,6 +2087,20 @@ public static <T> T getFlashAttribute(String name) {
 		return FacesLocal.getFlashAttribute(getContext(), name);
 	}
 
+	/**
+	 * Returns the flash scope attribute value associated with the given name, or computes the supplied value if absent.
+	 * @param <T> The expected return type.
+	 * @param name The flash scope attribute name.
+	 * @param computeIfAbsent The computed flash scope attribute value when absent. Useful if it represents a collection, map or bean.
+	 * @return The flash scope attribute value associated with the given name.
+	 * @throws ClassCastException When <code>T</code> is of wrong type.
+	 * @see ExternalContext#getFlash()
+	 * @since 3.0
+	 */
+	public static <T> T getFlashAttribute(String name, Supplier<T> computeIfAbsent) {
+		return FacesLocal.getFlashAttribute(getContext(), name, computeIfAbsent);
+	}
+
 	/**
 	 * Sets the flash scope attribute value associated with the given name.
 	 * @param name The flash scope attribute name.
@@ -2119,6 +2148,20 @@ public static <T> T getViewAttribute(String name) {
 		return FacesLocal.getViewAttribute(getContext(), name);
 	}
 
+	/**
+	 * Returns the view scope attribute value associated with the given name, or computes the supplied value if absent.
+	 * @param <T> The expected return type.
+	 * @param name The view scope attribute name.
+	 * @param computeIfAbsent The computed view scope attribute value when absent. Useful if it represents a collection, map or bean.
+	 * @return The view scope attribute value associated with the given name.
+	 * @throws ClassCastException When <code>T</code> is of wrong type.
+	 * @see ExternalContext#getViewMap()
+	 * @since 3.0
+	 */
+	public static <T> T getViewAttribute(String name, Supplier<T> computeIfAbsent) {
+		return FacesLocal.getViewAttribute(getContext(), name, computeIfAbsent);
+	}
+
 	/**
 	 * Sets the view scope attribute value associated with the given name.
 	 * @param name The view scope attribute name.
@@ -2166,6 +2209,20 @@ public static <T> T getSessionAttribute(String name) {
 		return FacesLocal.getSessionAttribute(getContext(), name);
 	}
 
+	/**
+	 * Returns the session scope attribute value associated with the given name, or computes the supplied value if absent.
+	 * @param <T> The expected return type.
+	 * @param name The session scope attribute name.
+	 * @param computeIfAbsent The computed session scope attribute value when absent. Useful if it represents a collection, map or bean.
+	 * @return The session scope attribute value associated with the given name.
+	 * @throws ClassCastException When <code>T</code> is of wrong type.
+	 * @see ExternalContext#getSessionMap()
+	 * @since 3.0
+	 */
+	public static <T> T getSessionAttribute(String name, Supplier<T> computeIfAbsent) {
+		return FacesLocal.getSessionAttribute(getContext(), name, computeIfAbsent);
+	}
+
 	/**
 	 * Sets the session scope attribute value associated with the given name.
 	 * @param name The session scope attribute name.
@@ -2213,6 +2270,20 @@ public static <T> T getApplicationAttribute(String name) {
 		return FacesLocal.getApplicationAttribute(getContext(), name);
 	}
 
+	/**
+	 * Returns the application scope attribute value associated with the given name, or computes the supplied value if absent.
+	 * @param <T> The expected return type.
+	 * @param name The application scope attribute name.
+	 * @param computeIfAbsent The computed application scope attribute value when absent. Useful if it represents a collection, map or bean.
+	 * @return The application scope attribute value associated with the given name.
+	 * @throws ClassCastException When <code>T</code> is of wrong type.
+	 * @see ExternalContext#getApplicationMap()
+	 * @since 3.0
+	 */
+	public static <T> T getApplicationAttribute(String name, Supplier<T> computeIfAbsent) {
+		return FacesLocal.getApplicationAttribute(getContext(), name, computeIfAbsent);
+	}
+
 	/**
 	 * Sets the application scope attribute value associated with the given name.
 	 * @param name The application scope attribute name.

diff --git a/src/main/java/org/omnifaces/util/FacesLocal.java b/src/main/java/org/omnifaces/util/FacesLocal.java
@@ -51,6 +51,7 @@
 import java.util.MissingResourceException;
 import java.util.ResourceBundle;
 import java.util.Set;
+import java.util.function.Supplier;
 import java.util.logging.Logger;
 
 import javax.el.ELContext;
@@ -1388,6 +1389,20 @@ public static <T> T getRequestAttribute(FacesContext context, String name) {
 		return (T) getRequestMap(context).get(name);
 	}
 
+	/**
+	 * @see Faces#getRequestAttribute(String, Supplier)
+	 */
+	public static <T> T getRequestAttribute(FacesContext context, String name, Supplier<T> computeIfAbsent) {
+		T value = getRequestAttribute(context, name);
+
+		if (value == null) {
+			value = computeIfAbsent.get();
+			setRequestAttribute(context, name, value);
+		}
+
+		return value;
+	}
+
 	/**
 	 * @see Faces#setRequestAttribute(String, Object)
 	 */
@@ -1420,6 +1435,20 @@ public static <T> T getFlashAttribute(FacesContext context, String name) {
 		return (T) getFlash(context).get(name);
 	}
 
+	/**
+	 * @see Faces#getFlashAttribute(String, Supplier)
+	 */
+	public static <T> T getFlashAttribute(FacesContext context, String name, Supplier<T> computeIfAbsent) {
+		T value = getFlashAttribute(context, name);
+
+		if (value == null) {
+			value = computeIfAbsent.get();
+			setFlashAttribute(context, name, value);
+		}
+
+		return value;
+	}
+
 	/**
 	 * @see Faces#setFlashAttribute(String, Object)
 	 */
@@ -1452,6 +1481,20 @@ public static <T> T getViewAttribute(FacesContext context, String name) {
 		return (T) getViewMap(context).get(name);
 	}
 
+	/**
+	 * @see Faces#getViewAttribute(String, Supplier)
+	 */
+	public static <T> T getViewAttribute(FacesContext context, String name, Supplier<T> computeIfAbsent) {
+		T value = getViewAttribute(context, name);
+
+		if (value == null) {
+			value = computeIfAbsent.get();
+			setViewAttribute(context, name, value);
+		}
+
+		return value;
+	}
+
 	/**
 	 * @see Faces#setViewAttribute(String, Object)
 	 */
@@ -1484,6 +1527,20 @@ public static <T> T getSessionAttribute(FacesContext context, String name) {
 		return (T) getSessionMap(context).get(name);
 	}
 
+	/**
+	 * @see Faces#getSessionAttribute(String, Supplier)
+	 */
+	public static <T> T getSessionAttribute(FacesContext context, String name, Supplier<T> computeIfAbsent) {
+		T value = getSessionAttribute(context, name);
+
+		if (value == null) {
+			value = computeIfAbsent.get();
+			setSessionAttribute(context, name, value);
+		}
+
+		return value;
+	}
+
 	/**
 	 * @see Faces#setSessionAttribute(String, Object)
 	 */
@@ -1516,6 +1573,20 @@ public static <T> T getApplicationAttribute(FacesContext context, String name) {
 		return (T) getApplicationMap(context).get(name);
 	}
 
+	/**
+	 * @see Faces#getApplicationAttribute(String, Supplier)
+	 */
+	public static <T> T getApplicationAttribute(FacesContext context, String name, Supplier<T> computeIfAbsent) {
+		T value = getApplicationAttribute(context, name);
+
+		if (value == null) {
+			value = computeIfAbsent.get();
+			setApplicationAttribute(context, name, value);
+		}
+
+		return value;
+	}
+
 	/**
 	 * @see Faces#setApplicationAttribute(String, Object)
 	 */