XCOMMONS-2450: Allow indicating to skip already installed extension in an install job

xwiki-commons-core/xwiki-commons-extension/xwiki-commons-extension-api/src/main/java/org/xwiki/extension/job/InstallRequest.java

@@ -37,6 +37,11 @@ public class InstallRequest extends AbstractExtensionRequest
      */
     public static final String PROPERTY_EXTENSION_PROPERTIES = "extension.properties";
 
+    /**
+     * @see #isFailOnExist()
+     */
+    public static final String PROPERTY_EXTENSION_FAIL_ON_EXIST = "extension.failOnExist";
+
     /**
      * Serialization identifier.
      */
@@ -57,6 +62,24 @@ public InstallRequest(Request request)
         super(request);
     }
 
+    /**
+     * @return whether or not the wiki creation should fail if the database already exists
+     * @since 14.5RC1
+     */
+    public boolean isFailOnExist()
+    {
+        return getProperty(PROPERTY_EXTENSION_FAIL_ON_EXIST, true);
+    }
+
+    /**
+     * @param failOnExist whether or not the wiki creation should fail if the database already exists
+     * @since 14.5RC1
+     */
+    public void setFailOnExist(boolean failOnExist)
+    {
+        setProperty(PROPERTY_EXTENSION_FAIL_ON_EXIST, failOnExist);
+    }
+
     /**
      * @return the custom extension properties to be set on each of the extensions that are going to be installed from
      *         this request

xwiki-commons-core/xwiki-commons-extension/xwiki-commons-extension-api/src/main/java/org/xwiki/extension/job/internal/AbstractInstallPlanJob.java

@@ -48,7 +48,7 @@
 import org.xwiki.extension.handler.ExtensionHandler;
 import org.xwiki.extension.internal.ExtensionFactory;
 import org.xwiki.extension.internal.ExtensionUtils;
-import org.xwiki.extension.job.ExtensionRequest;
+import org.xwiki.extension.job.InstallRequest;
 import org.xwiki.extension.job.plan.ExtensionPlanAction;
 import org.xwiki.extension.job.plan.ExtensionPlanAction.Action;
 import org.xwiki.extension.job.plan.ExtensionPlanNode;
@@ -66,7 +66,7 @@
  * @version $Id$
  * @since 4.1M1
  */
-public abstract class AbstractInstallPlanJob<R extends ExtensionRequest> extends AbstractExtensionPlanJob<R>
+public abstract class AbstractInstallPlanJob<R extends InstallRequest> extends AbstractExtensionPlanJob<R>
 {
     protected static class ModifableExtensionPlanNode extends DefaultExtensionPlanNode
     {
@@ -315,8 +315,10 @@ protected void installExtension(ExtensionId extensionId, boolean dependency, Str
 
         ModifableExtensionPlanNode node = installExtension(extensionId, dependency, namespace);
 
-        addExtensionNode(node);
-        parentBranch.add(node);
+        if (node != null) {
+            addExtensionNode(node);
+            parentBranch.add(node);
+        }
     }
 
     private boolean checkCoreDependency(ExtensionDependency extensionDependency,
@@ -716,10 +718,12 @@ && hasIncompatileRootDependency(extensionDependency)) {
         ModifableExtensionPlanNode node =
             installExtensionDependency(targetDependency, true, namespace, extensionContext, parents);
 
-        node.versionConstraint = versionConstraint;
+        if (node != null) {
+            node.versionConstraint = versionConstraint;
 
-        addExtensionNode(node);
-        parentBranch.add(node);
+            addExtensionNode(node);
+            parentBranch.add(node);
+        }
     }
 
     /**
@@ -993,7 +997,9 @@ private ModifableExtensionPlanNode installExtension(Extension sourceExtension, E
 
         // Check if the extension is already installed
         Extension installedExtension = checkInstalledExtension(rewrittenExtension, namespace);
-        if (installedExtension != rewrittenExtension) {
+        if (installedExtension == null) {
+            return null;
+        } else if (installedExtension != rewrittenExtension) {
             sourceExtension = installedExtension;
 
             // Rewrite the extension
@@ -1155,8 +1161,15 @@ private Extension checkInstalledExtension(Extension extension, String namespace)
             this.installedExtensionRepository.getInstalledExtension(extension.getId());
         if (installedExtension != null && installedExtension.isInstalled(namespace)) {
             if (installedExtension.isValid(namespace)) {
-                throw new InstallException(String.format("Extension [%s] is already installed on namespace [%s]",
-                    extension.getId(), namespace));
+                if (this.getRequest().isFailOnExist()) {
+                    throw new InstallException(String.format("Extension [%s] is already installed on namespace [%s]",
+                        extension.getId(), namespace));
+                } else {
+                    this.logger.warn("Extension [{}] is already installed on namespace [{}]",
+                        installedExtension.getId(), namespace);
+
+                    return null;
+                }
             }
 
             // In case the extension is already installed on the namespace but is invalid continue with it to make clear