From abd6756758404ea2efbf26eed7d36eb48894ae44 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christoph=20L=C3=A4ubrich?= <laeubi@laeubi-soft.de>
Date: Sat, 21 Dec 2024 08:20:31 +0100
Subject: [PATCH] Add "replace" as a default available transformer

A while back in the incubation phase there was a dedicated bundle that
provided a "replace" transformer.

As this is the very basic transformation and do not require any special
dependency it is now added back (in a slightly enhanced implementation)
as being available by default.
---
 .../META-INF/MANIFEST.MF                      |  2 +-
 .../transforms/ReplaceTransformer.java        | 50 +++++++++++++++++++
 .../internal/transforms/TransformerHook.java  |  1 +
 3 files changed, 52 insertions(+), 1 deletion(-)
 create mode 100644 bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/ReplaceTransformer.java

diff --git a/bundles/org.eclipse.equinox.transforms.hook/META-INF/MANIFEST.MF b/bundles/org.eclipse.equinox.transforms.hook/META-INF/MANIFEST.MF
index 0439ba08288..2069b071de1 100644
--- a/bundles/org.eclipse.equinox.transforms.hook/META-INF/MANIFEST.MF
+++ b/bundles/org.eclipse.equinox.transforms.hook/META-INF/MANIFEST.MF
@@ -3,7 +3,7 @@ Bundle-ManifestVersion: 2
 Bundle-Name: %bundleName
 Bundle-Vendor: %providerName
 Bundle-SymbolicName: org.eclipse.equinox.transforms.hook
-Bundle-Version: 1.4.100.qualifier
+Bundle-Version: 1.4.200.qualifier
 Fragment-Host: org.eclipse.osgi;bundle-version="[3.10.0,4.0.0)"
 Bundle-RequiredExecutionEnvironment: JavaSE-17
 Bundle-Localization: transformsHook
diff --git a/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/ReplaceTransformer.java b/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/ReplaceTransformer.java
new file mode 100644
index 00000000000..15017912fa9
--- /dev/null
+++ b/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/ReplaceTransformer.java
@@ -0,0 +1,50 @@
+/*******************************************************************************
+ * Copyright (c) 2024 Christoph Läubrich and others.
+ *
+ * This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License 2.0
+ * which accompanies this distribution, and is available at
+ * https://www.eclipse.org/legal/epl-2.0/
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ *
+ * Contributors:
+ *     Christoph Läubrich - initial API and implementation
+ *******************************************************************************/
+package org.eclipse.equinox.internal.transforms;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.util.Map;
+import org.eclipse.osgi.framework.log.FrameworkLogEntry;
+import org.osgi.framework.BundleContext;
+import org.osgi.framework.FrameworkUtil;
+
+/**
+ * Basic default transformer that simply replaces a matching resource with
+ * another.
+ */
+class ReplaceTransformer {
+
+	static final String TYPE = "replace"; //$NON-NLS-1$
+	private TransformerHook hook;
+
+	ReplaceTransformer(TransformerHook hook) {
+		this.hook = hook;
+	}
+
+	public InputStream getInputStream(InputStream inputStream, final URL transformerUrl) {
+		try {
+			return transformerUrl.openStream();
+		} catch (IOException e) {
+			hook.log(FrameworkLogEntry.WARNING, String.format("Can't replace resource with %s", transformerUrl), e); //$NON-NLS-1$
+			return null;
+		}
+	}
+
+	public static void register(BundleContext context, TransformerHook transformerHook) {
+		context.registerService(Object.class, new ReplaceTransformer(transformerHook),
+				FrameworkUtil.asDictionary(Map.of(TransformTuple.TRANSFORMER_TYPE, TYPE)));
+	}
+}
diff --git a/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/TransformerHook.java b/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/TransformerHook.java
index 1eecc150be6..1f0bcea632f 100644
--- a/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/TransformerHook.java
+++ b/bundles/org.eclipse.equinox.transforms.hook/src/org/eclipse/equinox/internal/transforms/TransformerHook.java
@@ -46,6 +46,7 @@ public void addHooks(HookRegistry hookRegistry) {
 
 	public void start(BundleContext context) throws BundleException {
 		try {
+			ReplaceTransformer.register(context, this);
 			this.transformers = new TransformerList(context, logServices);
 		} catch (InvalidSyntaxException e) {
 			throw new BundleException("Problem registering service tracker: transformers", e); //$NON-NLS-1$