#199: fix failing view scope unload when bean is constructed for first

time during postback on same view (i.e. not on initial request; this is
unusual but not impossible). For this, added Ajax#load().

src/main/java/org/omnifaces/cdi/viewscope/ViewScopeManager.java

@@ -16,6 +16,7 @@
 package org.omnifaces.cdi.viewscope;
 
 import static java.lang.Boolean.TRUE;
+import static org.omnifaces.util.Ajax.load;
 import static org.omnifaces.util.Ajax.oncomplete;
 import static org.omnifaces.util.Components.addScriptResourceToBody;
 import static org.omnifaces.util.Components.addScriptResourceToHead;
@@ -233,17 +234,23 @@ private void createViewScope(UUID id) {
 		activeViewScopes.put(id, new BeanStorage(DEFAULT_BEANS_PER_VIEW_SCOPE));
 
 		FacesContext context = FacesContext.getCurrentInstance();
+		boolean ajaxRequestWithPartialRendering = isAjaxRequestWithPartialRendering(context);
 
-		if (context.getCurrentPhaseId() != PhaseId.RENDER_RESPONSE || TRUE.equals(context.getAttributes().get(StateManager.IS_BUILDING_INITIAL_STATE))) {
-			addScriptResourceToHead("omnifaces", "omnifaces.js");
-		}
-		else if (!Hacks.isScriptResourceRendered(context, new ResourceIdentifier("omnifaces", "omnifaces.js"))) {
-			addScriptResourceToBody("omnifaces", "unload.js");
+		if (!Hacks.isScriptResourceRendered(context, new ResourceIdentifier("omnifaces", "omnifaces.js"))) {
+			if (ajaxRequestWithPartialRendering) {
+				load("omnifaces", "unload.js");
+			}
+			else if (context.getCurrentPhaseId() != PhaseId.RENDER_RESPONSE || TRUE.equals(context.getAttributes().get(StateManager.IS_BUILDING_INITIAL_STATE))) {
+				addScriptResourceToHead("omnifaces", "omnifaces.js");
+			}
+			else {
+				addScriptResourceToBody("omnifaces", "unload.js");
+			}
 		}
 
 		String script = String.format(SCRIPT_INIT, id);
 
-		if (isAjaxRequestWithPartialRendering(context)) {
+		if (ajaxRequestWithPartialRendering) {
 			oncomplete(script);
 		}
 		else {

src/main/java/org/omnifaces/util/Ajax.java

@@ -12,15 +12,22 @@
  */
 package org.omnifaces.util;
 
+import static java.nio.charset.StandardCharsets.UTF_8;
 import static org.omnifaces.util.Components.getCurrentComponent;
 import static org.omnifaces.util.Components.getCurrentForm;
+import static org.omnifaces.util.Faces.getApplication;
+import static org.omnifaces.util.Faces.isAjaxRequestWithPartialRendering;
 
 import java.beans.Introspector;
+import java.io.IOException;
 import java.util.Collection;
 import java.util.Date;
 import java.util.Map;
 import java.util.Map.Entry;
+import java.util.Scanner;
 
+import javax.faces.FacesException;
+import javax.faces.application.Resource;
 import javax.faces.component.UIColumn;
 import javax.faces.component.UIComponent;
 import javax.faces.component.UIData;
@@ -59,6 +66,11 @@ public final class Ajax {
 
 	// Constants ------------------------------------------------------------------------------------------------------
 
+	private static final String ERROR_NO_SCRIPT_RESOURCE =
+		"";
+	private static final String ERROR_NO_PARTIAL_RENDERING =
+		"The current request is not an ajax request with partial rendering."
+			+ " Use Components#addScriptXxx() methods instead.";
 	private static final String ERROR_ARGUMENTS_LENGTH =
 		"The arguments length must be even. Encountered %d items.";
 	private static final String ERROR_ARGUMENT_TYPE =
@@ -229,12 +241,44 @@ private static void updateColumnCells(UIData table, int index, int rowCount) {
 		}
 	}
 
+	/**
+	 * Load given script resource on complete of the current ajax response. Basically, it loads the script resource as
+	 * a {@link String} and then delegates it to {@link #oncomplete(String...)}.
+	 * @param libraryName Library name of the JavaScript resource.
+	 * @param resourceName Resource name of the JavaScript resource.
+	 * @throws IllegalArgumentException When given script resource cannot be found.
+	 * @throws IllegalStateException When current request is not an ajax request with partial rendering. You should use
+	 * either {@link Components#addScriptResourceToBody(String, String)}
+	 * or {@link Components#addScriptResourceToHead(String, String)} instead.
+	 * @since 2.3
+	 */
+	public static void load(String libraryName, String resourceName) {
+		Resource resource = getApplication().getResourceHandler().createResource(resourceName, libraryName);
+
+		if (resource == null) {
+			throw new IllegalArgumentException(ERROR_NO_SCRIPT_RESOURCE);
+		}
+
+		try (Scanner scanner = new Scanner(resource.getInputStream(), UTF_8.name())) {
+			oncomplete(scanner.useDelimiter("\\A").next());
+		}
+		catch (IOException e) {
+			throw new FacesException(e);
+		}
+	}
+
 	/**
 	 * Execute the given scripts on complete of the current ajax response.
 	 * @param scripts The scripts to be executed.
+	 * @throws IllegalStateException When current request is not an ajax request with partial rendering. You should use
+	 * {@link Components#addScriptToBody(String)} instead.
 	 * @see OmniPartialViewContext#addCallbackScript(String)
 	 */
 	public static void oncomplete(String... scripts) {
+		if (!isAjaxRequestWithPartialRendering()) {
+			throw new IllegalStateException(ERROR_NO_PARTIAL_RENDERING);
+		}
+
 		OmniPartialViewContext context = OmniPartialViewContext.getCurrentInstance();
 
 		for (String script : scripts) {

src/main/java/org/omnifaces/viewhandler/RestorableViewHandler.java

@@ -115,6 +115,7 @@ public UIViewRoot restoreView(FacesContext context, String viewId) {
 	private boolean restoreViewRootState(FacesContext context, ResponseStateManager manager, UIViewRoot view) {
 		Object state = manager.getState(context, view.getViewId());
 
+		// TODO: this assumes partial state saving not full state saving (thus doesn't work on full state saving).
 		if (state == null || !(state instanceof Object[]) || ((Object[]) state).length < 2 || !(((Object[]) state)[1] instanceof Map)) {
 			return false;
 		}