Adding support for merging a list of configs external to the second fig

fig-core/src/main/java/twigkit/fig/Fig.java

@@ -2,6 +2,7 @@
 
 import twigkit.fig.annotation.InjectionConfigurator;
 import twigkit.fig.loader.Loader;
+import twigkit.fig.util.ConfigUtils;
 import twigkit.fig.visitor.ConfigFinder;
 
 import java.util.Arrays;
@@ -112,16 +113,9 @@ public Fig add(Config config, String... path) {
 			if (!configs.containsKey(path[0])) {
 				add(new Config(path[0], config.loader));
 			}
+
 			Config parent = configs.get(path[0]);
-			for (int i = 1; i < path.length - 1; i++) {
-				Config c = parent.extension(path[i]);
-				if (c == null && i < path.length) {
-					c = new Config(path[i]);
-					parent.extend_with(c);
-				}
-                parent = c;
-			}
-			parent.extend_with(config);
+			ConfigUtils.addToParent(config, parent, path);
 		}
 
 		return this;

fig-core/src/main/java/twigkit/fig/loader/MergedPropertiesLoader.java

@@ -5,6 +5,7 @@
 import org.slf4j.LoggerFactory;
 import twigkit.fig.Config;
 import twigkit.fig.Fig;
+import twigkit.fig.util.ConfigUtils;
 import twigkit.fig.util.FigUtils;
 import twigkit.fig.util.FileUtils;
 
@@ -23,15 +24,19 @@ public class MergedPropertiesLoader implements Loader {
 
     private String pathToPrimaryFig;
     private String pathToSecondaryFig;
+    private String configsToMerge;
 
     public MergedPropertiesLoader(String pathToPrimaryFig, String pathToSecondaryFig) {
         this.pathToPrimaryFig = pathToPrimaryFig;
         this.pathToSecondaryFig = pathToSecondaryFig;
     }
 
     /**
-     * This method loads the given primary {@link Fig} and a second {@link Fig} then merges the second {@link Fig}
-     * with the primary {@link Fig}.
+     * This method first loads the given primary {@link Fig} and a second {@link Fig} then merges the
+     * second {@link Fig} with the primary {@link Fig}.
+     *
+     * Any additional configurations set on the {@link Loader} that are not part of the secondary {@link Fig}
+     * will also be merged with the primary {@link Fig} once the secondary {@link Fig} has been merged.
      *
      * @param fig The primary {@link Fig}
      */
@@ -66,6 +71,10 @@ public void load(Fig fig) {
                 logger.error("Both the path to the primary fig: \"{}\" and the path to the secondary fig: \"{}\" are invalid. Unable to load configurations.", pathToPrimaryFig, pathToSecondaryFig);
             }
         }
+
+        if (configsToMerge != null) {
+            FigUtils.mergeConfigs(fig, ConfigUtils.asList(configsToMerge, this));
+        }
     }
 
     public void write(Config config) throws IOException {
@@ -75,4 +84,21 @@ public void write(Config config) throws IOException {
     public void delete(Config config) throws IOException {
         throw new IOException("Delete operation not supported.");
     }
+
+    /**
+     * Set a config or sequence of configs that should be merged with the primary {@link Fig} after merging the
+     * secondary {@link Fig}. A config should be given in the following form:
+     *
+     * parent.child[property:value
+     *
+     * If more than one config is to be merged, subsequent configs should be separated with an ampersand, for
+     * example:
+     *
+     * parent.child[property:value&parent[property:value
+     *
+     * @param configsToMerge The config or sequence of configs to be merged with the primary {@link Fig}.
+     */
+    public void setConfigsToMerge(String configsToMerge) {
+        this.configsToMerge = configsToMerge;
+    }
 }

fig-core/src/main/java/twigkit/fig/util/ConfigUtils.java

@@ -0,0 +1,101 @@
+package twigkit.fig.util;
+
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import twigkit.fig.Config;
+import twigkit.fig.Value;
+import twigkit.fig.loader.Loader;
+
+import java.util.ArrayList;
+import java.util.List;
+
+/**
+ * Utility class to perform operations on a {@link Config} or set of {@link Config}s.
+ *
+ * @author scottbrown
+ */
+public class ConfigUtils {
+
+    private static final Logger logger = LoggerFactory.getLogger(ConfigUtils.class);
+
+    /**
+     * Convert the given config or sequence of configs into a {@link List} of {@link Config}s.
+     *
+     * A config should be given in the following form:
+     *
+     * parent.child[property:value
+     *
+     * If more than one config is to be merged, subsequent configs should be separated with an ampersand, for
+     * example:
+     *
+     * parent.child[property:value&parent[property:value
+     *
+     * @param configurations The config or sequence of configs to be converted into a {@link List} of {@link Config}s.
+     * @param loader The {@link Loader} that backs each instance of the {@link Config}.
+     * @return A {@link List} of {@link Config}s.
+     */
+    public static List<Config> asList(String configurations, Loader loader) {
+        List<Config> configs = null;
+
+        if (configurations != null) {
+            configs = new ArrayList<Config>();
+
+            for (String c : configurations.split("&")) {
+
+                String[] configDetails = c.split(":");
+
+                String property = configDetails[0].substring(configDetails[0].indexOf("[") + 1, configDetails[0].length());
+                String[] path = configDetails[0].substring(0, configDetails[0].indexOf("[")).split("\\.");
+
+                Config config = null;
+                if (path.length == 1) {
+                    config = new Config(path[0], loader);
+                } else if (path.length > 1) {
+                    config = new Config(path[path.length - 1], loader);
+                } else {
+                    logger.warn("No configuration given for property {}. This property will be ignored", property);
+                }
+
+                if (config != null) {
+                    config.set(new Value<Object>(property, configDetails[1], false));
+
+                    if (path.length == 1) {
+                        configs.add(config);
+                    } else {
+                        Config parent = new Config(path[0], loader);
+                        addToParent(config, parent, path);
+                        configs.add(config.parents().get(0));
+                    }
+                }
+            }
+        }
+
+        return configs;
+    }
+
+    /**
+     * Add the given {@link Config} to the given parent {@link Config}.
+     *
+     * @param config The {@link Config} to be added as a child of the given parent {@link Config}.
+     * @param parent The {@link Config} that will be a parent of the given {@link Config}
+     * @param path The configuration path pointing from the parent down to the child.
+     */
+    public static void addToParent(Config config, Config parent, String... path) {
+        if (parent != null) {
+            for (int i = 1; i < path.length - 1; i++) {
+                Config child = parent.extension(path[i]);
+
+                if (child == null && i < path.length) {
+                    child = new Config(path[i]);
+                    parent.extend_with(child);
+                }
+
+                parent = child;
+            }
+
+            if (config != null) {
+                parent.extend_with(config);
+            }
+        }
+    }
+}

fig-core/src/main/java/twigkit/fig/util/FigUtils.java

@@ -27,6 +27,17 @@ public static void merge(Fig primary, Fig secondary) {
         }
     }
 
+    /**
+     * Merge a collection of {@link Config}s into a primary {@link Fig}.
+     * @param primary The {@link Fig} to be updated.
+     * @param configs The {@link Config}s to be merged.
+     */
+    public static void mergeConfigs(Fig primary, Collection<Config> configs) {
+        if (primary != null && configs != null) {
+            merge(primary, primary.configs(), configs);
+        }
+    }
+
     /**
      * Merge a collection of secondary {@link Config}s into a collection of primary {@link Config}s.
      * @param fig The {@link Fig} to be updated.

fig-core/src/test/java/twigkit.fig/loader/MergedPropertiesLoaderTest.java

@@ -5,10 +5,13 @@
 import org.junit.rules.ExpectedException;
 import twigkit.fig.Config;
 import twigkit.fig.Fig;
+import twigkit.fig.util.ConfigUtils;
+import twigkit.fig.util.FigUtils;
 import twigkit.fig.visitor.ConfigTreeWriter;
 
 import java.io.IOException;
 import java.util.Iterator;
+import java.util.List;
 
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
@@ -136,6 +139,22 @@ public void testExtensionsWithTheSameNameUnderDifferentParentConfigsAreHandledCo
         new ConfigTreeWriter(fig.get("people"));
     }
 
+    @Test
+    public void testMergedPropertiesLoaderMergesConfigList() {
+        MergedPropertiesLoader loader = new MergedPropertiesLoader("confs", "confs_dev");
+
+        String configsToMerge = "people.detail[enabled:true&sub.group.folder-extension[group-folder-extension-key:test";
+        loader.setConfigsToMerge(configsToMerge);
+
+        Fig fig = Fig.getInstance(loader);
+
+        assertEquals(2, fig.get("people", "detail").values().size());
+        assertEquals("true", fig.get("people", "detail").value("enabled").as_string());
+
+        assertEquals(2, fig.get("sub", "group", "folder-extension").values().size());
+        assertEquals("test", fig.get("sub", "group", "folder-extension").value("group-folder-extension-key").as_string());
+    }
+
     @Test
     public void testFallbackFigIsReturnedWhenTheOtherIsEmpty() {
         Fig fig1 = Fig.getInstance(new PropertiesLoader("confs"));

fig-core/src/test/java/twigkit.fig/util/ConfigUtilsTest.java

@@ -0,0 +1,37 @@
+package twigkit.fig.util;
+
+import org.junit.Test;
+import twigkit.fig.Config;
+import twigkit.fig.loader.PropertiesLoader;
+
+import java.util.List;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * @author scottbrown
+ */
+public class ConfigUtilsTest {
+
+    @Test
+    public void testConvertingSingleConfigStringToConfigList() {
+        String configsToMerge = "companies[host:test";
+        List<Config> configs = ConfigUtils.asList(configsToMerge, new PropertiesLoader("conf"));
+
+        assertEquals(1, configs.size());
+        assertEquals("companies", configs.get(0).name());
+        assertEquals("test", configs.get(0).value("host").as_string());
+    }
+
+    @Test
+    public void testConvertingMultipleConfigStringToConfigList() {
+        String configsToMerge = "people.detail[enabled:true&sub.group.folder-extension[group-folder-extension-key:test";
+        List<Config> configs = ConfigUtils.asList(configsToMerge, new PropertiesLoader("conf"));
+
+        assertEquals(2, configs.size());
+        assertEquals("people", configs.get(0).name());
+        assertEquals("true", configs.get(0).extension("detail").value("enabled").as_string());
+        assertEquals("sub", configs.get(1).name());
+        assertEquals("test", configs.get(1).extension("group").extension("folder-extension").value("group-folder-extension-key").as_string());
+    }
+}

fig-core/src/test/java/twigkit.fig/util/FigUtilsTest.java

@@ -3,8 +3,11 @@
 import org.junit.Test;
 import twigkit.fig.Config;
 import twigkit.fig.Fig;
+import twigkit.fig.loader.MergedPropertiesLoader;
 import twigkit.fig.loader.PropertiesLoader;
 
+import java.util.List;
+
 import static org.junit.Assert.assertEquals;
 import static org.junit.Assert.assertNotNull;
 
@@ -111,4 +114,21 @@ public void testFigRemainsUnchangedWhenMergingNullFig() {
         FigUtils.merge(fig, null);
         assertEquals(5, fig.configs().size());
     }
+
+    @Test
+    public void testMergingCollectionOfConfigsIntoFig() {
+        PropertiesLoader loader = new PropertiesLoader("confs");
+        Fig fig = Fig.getInstance(loader);
+
+        String configsToMerge = "people.detail[enabled:true&sub.group.folder-extension[group-folder-extension-key:test";
+        List<Config> configs = ConfigUtils.asList(configsToMerge, loader);
+
+        FigUtils.mergeConfigs(fig, configs);
+
+        assertEquals(2, fig.get("people", "detail").values().size());
+        assertEquals("true", fig.get("people", "detail").value("enabled").as_string());
+
+        assertEquals(2, fig.get("sub", "group", "folder-extension").values().size());
+        assertEquals("test", fig.get("sub", "group", "folder-extension").value("group-folder-extension-key").as_string());
+    }
 }