[marketplace] Add add-on handler for block libraries (openhab#2598)

Related to openhab/openhab-webui#1225.

This add-on handler supports installing block libraries in the
UIComponentRegistry, `ui:blocks` namespace.

It is very similar to the CommunityUIWidgetAddonHandler, as the format
is the same, so are the features and implementation, the only
differences being:

- Supported content type: `application/vnd.openhab.uicomponent;type=blocks`
  (vs. `application/vnd.openhab.uicomponent;type=widget`)
- Discourse category nb.: 76 (vs. 75)
- Inferred Add-on type: "automation" (vs. "ui")

Signed-off-by: Yannick Schaus <github@schaus.net>

bundles/org.openhab.core.addon.marketplace/src/main/java/org/openhab/core/addon/marketplace/internal/community/CommunityBlockLibaryAddonHandler.java

@@ -0,0 +1,121 @@
+/**
+ * Copyright (c) 2010-2021 Contributors to the openHAB project
+ *
+ * See the NOTICE file(s) distributed with this work for additional
+ * information.
+ *
+ * This program and the accompanying materials are made available under the
+ * terms of the Eclipse Public License 2.0 which is available at
+ * http://www.eclipse.org/legal/epl-2.0
+ *
+ * SPDX-License-Identifier: EPL-2.0
+ */
+package org.openhab.core.addon.marketplace.internal.community;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.net.URL;
+import java.nio.charset.StandardCharsets;
+import java.text.SimpleDateFormat;
+
+import org.eclipse.jdt.annotation.NonNullByDefault;
+import org.openhab.core.addon.Addon;
+import org.openhab.core.addon.marketplace.MarketplaceAddonHandler;
+import org.openhab.core.addon.marketplace.MarketplaceHandlerException;
+import org.openhab.core.ui.components.RootUIComponent;
+import org.openhab.core.ui.components.UIComponentRegistry;
+import org.openhab.core.ui.components.UIComponentRegistryFactory;
+import org.osgi.service.component.annotations.Activate;
+import org.osgi.service.component.annotations.Component;
+import org.osgi.service.component.annotations.Reference;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+
+import com.fasterxml.jackson.databind.ObjectMapper;
+import com.fasterxml.jackson.dataformat.yaml.YAMLFactory;
+
+/**
+ * A {@link MarketplaceAddonHandler} implementation, which handles block libraries as YAML files and installs
+ * them by adding them to the {@link UIComponentRegistry} for the ui:blocks namespace.
+ *
+ * @author Yannick Schaus - Initial contribution and API
+ *
+ */
+@Component(immediate = true)
+@NonNullByDefault
+public class CommunityBlockLibaryAddonHandler implements MarketplaceAddonHandler {
+    private static final String YAML_DOWNLOAD_URL_PROPERTY = "yaml_download_url";
+    private static final String YAML_CONTENT_PROPERTY = "yaml_content";
+    private static final String BLOCKLIBRARIES_CONTENT_TYPE = "application/vnd.openhab.uicomponent;type=blocks";
+
+    private final Logger logger = LoggerFactory.getLogger(CommunityBlockLibaryAddonHandler.class);
+    ObjectMapper yamlMapper;
+
+    private UIComponentRegistry blocksRegistry;
+
+    @Activate
+    public CommunityBlockLibaryAddonHandler(final @Reference UIComponentRegistryFactory uiComponentRegistryFactory) {
+        this.blocksRegistry = uiComponentRegistryFactory.getRegistry("ui:blocks");
+        this.yamlMapper = new ObjectMapper(new YAMLFactory());
+        yamlMapper.findAndRegisterModules();
+        this.yamlMapper.setDateFormat(new SimpleDateFormat("MMM d, yyyy, hh:mm:ss aa"));
+    }
+
+    @Override
+    public boolean supports(String type, String contentType) {
+        return "automation".equals(type) && BLOCKLIBRARIES_CONTENT_TYPE.equals(contentType);
+    }
+
+    @Override
+    public boolean isInstalled(String id) {
+        return blocksRegistry.getAll().stream().anyMatch(w -> w.hasTag(id));
+    }
+
+    @Override
+    public void install(Addon addon) throws MarketplaceHandlerException {
+        try {
+            String yamlDownloadUrl = (String) addon.getProperties().get(YAML_DOWNLOAD_URL_PROPERTY);
+            String yamlContent = (String) addon.getProperties().get(YAML_CONTENT_PROPERTY);
+
+            if (yamlDownloadUrl != null) {
+                addWidgetAsYAML(addon.getId(), getWidgetFromURL(yamlDownloadUrl));
+            } else if (yamlContent != null) {
+                addWidgetAsYAML(addon.getId(), yamlContent);
+            } else {
+                throw new IllegalArgumentException("Couldn't find the block library in the add-on entry");
+            }
+        } catch (IOException e) {
+            logger.error("Block library from marketplace cannot be downloaded: {}", e.getMessage());
+            throw new MarketplaceHandlerException("Widget cannot be downloaded.", e);
+        } catch (Exception e) {
+            logger.error("Block library from marketplace is invalid: {}", e.getMessage());
+            throw new MarketplaceHandlerException("Widget is not valid.", e);
+        }
+    }
+
+    @Override
+    public void uninstall(Addon addon) throws MarketplaceHandlerException {
+        blocksRegistry.getAll().stream().filter(w -> w.hasTag(addon.getId())).forEach(w -> {
+            blocksRegistry.remove(w.getUID());
+        });
+    }
+
+    private String getWidgetFromURL(String urlString) throws IOException {
+        URL u = new URL(urlString);
+        try (InputStream in = u.openStream()) {
+            return new String(in.readAllBytes(), StandardCharsets.UTF_8);
+        }
+    }
+
+    private void addWidgetAsYAML(String id, String yaml) {
+        try {
+            RootUIComponent widget = yamlMapper.readValue(yaml, RootUIComponent.class);
+            // add a tag with the add-on ID to be able to identify the block library in the registry
+            widget.addTag(id);
+            blocksRegistry.add(widget);
+        } catch (IOException e) {
+            logger.error("Unable to parse YAML: {}", e.getMessage());
+            throw new IllegalArgumentException("Unable to parse YAML");
+        }
+    }
+}

bundles/org.openhab.core.addon.marketplace/src/main/java/org/openhab/core/addon/marketplace/internal/community/CommunityMarketplaceAddonService.java

@@ -75,6 +75,7 @@ public class CommunityMarketplaceAddonService implements AddonService {
     public static final String KAR_CONTENT_TYPE = "application/vnd.openhab.feature;type=karfile";
     public static final String RULETEMPLATES_CONTENT_TYPE = "application/vnd.openhab.ruletemplate";
     public static final String UIWIDGETS_CONTENT_TYPE = "application/vnd.openhab.uicomponent;type=widget";
+    public static final String BLOCKLIBRARIES_CONTENT_TYPE = "application/vnd.openhab.uicomponent;type=blocks";
 
     // constants for the configuration properties
     static final String CONFIG_URI = "system:marketplace";
@@ -94,6 +95,7 @@ public class CommunityMarketplaceAddonService implements AddonService {
     private static final Integer BUNDLES_CATEGORY = 73;
     private static final Integer RULETEMPLATES_CATEGORY = 74;
     private static final Integer UIWIDGETS_CATEGORY = 75;
+    private static final Integer BLOCKLIBRARIES_CATEGORY = 76;
 
     private static final String PUBLISHED_TAG = "published";
 
@@ -281,6 +283,8 @@ public String getAddonId(URI addonURI) {
             return TAG_ADDON_TYPE_MAP.get("automation");
         } else if (UIWIDGETS_CATEGORY.equals(category)) {
             return TAG_ADDON_TYPE_MAP.get("ui");
+        } else if (BLOCKLIBRARIES_CATEGORY.equals(category)) {
+            return TAG_ADDON_TYPE_MAP.get("automation");
         } else if (BUNDLES_CATEGORY.equals(category)) {
             // try to get it from tags if we have tags
             return tags.stream().map(TAG_ADDON_TYPE_MAP::get).filter(Objects::nonNull).findFirst().orElse(null);
@@ -296,6 +300,8 @@ private String getContentType(@Nullable Integer category, List<String> tags) {
             return RULETEMPLATES_CONTENT_TYPE;
         } else if (UIWIDGETS_CATEGORY.equals(category)) {
             return UIWIDGETS_CONTENT_TYPE;
+        } else if (BLOCKLIBRARIES_CATEGORY.equals(category)) {
+            return BLOCKLIBRARIES_CONTENT_TYPE;
         } else if (BUNDLES_CATEGORY.equals(category)) {
             if (tags.contains("kar")) {
                 return KAR_CONTENT_TYPE;