Refactor experiment and events getters (#179)

* remove throws declarations on methods since we never actually throw. Change docs to explain that we send it to the error handler instead
* rename `getExperimentOrThrow` to `getExperimentForKey`
* rename `getEventTypeOrThrow` to `getEventTypeForName`
* move `getExperimentForKey` from Optimizely.java to ProjectConfig.java
* move `getEventTypeForName` from Optimizely.java to ProjectConfig.java.

Author: wangjoshuah

core-api/src/main/java/com/optimizely/ab/Optimizely.java

@@ -32,7 +32,6 @@
 import com.optimizely.ab.config.parser.DefaultConfigParser;
 import com.optimizely.ab.error.ErrorHandler;
 import com.optimizely.ab.error.NoOpErrorHandler;
-import com.optimizely.ab.error.RaiseExceptionErrorHandler;
 import com.optimizely.ab.event.EventHandler;
 import com.optimizely.ab.event.LogEvent;
 import com.optimizely.ab.event.internal.BuildVersionInfo;
@@ -42,7 +41,6 @@
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
-import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.ThreadSafe;
@@ -131,7 +129,7 @@ Variation activate(@Nonnull String experimentKey,
 
         ProjectConfig currentConfig = getProjectConfig();
 
-        Experiment experiment = getExperimentOrThrow(currentConfig, experimentKey);
+        Experiment experiment = currentConfig.getExperimentForKey(experimentKey, errorHandler);
         if (experiment == null) {
             // if we're unable to retrieve the associated experiment, return null
             logger.info("Not activating user \"{}\" for experiment \"{}\".", userId, experimentKey);
@@ -228,7 +226,7 @@ public void track(@Nonnull String eventName,
 
         ProjectConfig currentConfig = getProjectConfig();
 
-        EventType eventType = getEventTypeOrThrow(currentConfig, eventName);
+        EventType eventType = currentConfig.getEventTypeForName(eventName, errorHandler);
         if (eventType == null) {
             // if no matching event type could be found, do not dispatch an event
             logger.info("Not tracking event \"{}\" for user \"{}\".", eventName, userId);
@@ -638,7 +636,7 @@ Variation getVariation(@Nonnull String experimentKey,
 
         ProjectConfig currentConfig = getProjectConfig();
 
-        Experiment experiment = getExperimentOrThrow(currentConfig, experimentKey);
+        Experiment experiment = currentConfig.getExperimentForKey(experimentKey, errorHandler);
         if (experiment == null) {
             // if we're unable to retrieve the associated experiment, return null
             return null;
@@ -720,64 +718,6 @@ public UserProfileService getUserProfileService() {
 
     //======== Helper methods ========//
 
-    /**
-     * Helper method to retrieve the {@link Experiment} for the given experiment key.
-     * If {@link RaiseExceptionErrorHandler} is provided, either an experiment is returned, or an exception is thrown.
-     * If {@link NoOpErrorHandler} is used, either an experiment or {@code null} is returned.
-     *
-     * @param projectConfig the current project config
-     * @param experimentKey the experiment to retrieve from the current project config
-     * @return the experiment for given experiment key
-     *
-     * @throws UnknownExperimentException if there are no experiments in the current project config with the given
-     * experiment key
-     */
-    private @CheckForNull Experiment getExperimentOrThrow(@Nonnull ProjectConfig projectConfig,
-                                                          @Nonnull String experimentKey)
-        throws UnknownExperimentException {
-
-        Experiment experiment = projectConfig
-            .getExperimentKeyMapping()
-            .get(experimentKey);
-
-        // if the given experiment key isn't present in the config, log and potentially throw an exception
-        if (experiment == null) {
-            String unknownExperimentError = String.format("Experiment \"%s\" is not in the datafile.", experimentKey);
-            logger.error(unknownExperimentError);
-            errorHandler.handleError(new UnknownExperimentException(unknownExperimentError));
-        }
-
-        return experiment;
-    }
-
-    /**
-     * Helper method to retrieve the {@link EventType} for the given event name.
-     * If {@link RaiseExceptionErrorHandler} is provided, either an event type is returned, or an exception is thrown.
-     * If {@link NoOpErrorHandler} is used, either an event type or {@code null} is returned.
-     *
-     * @param projectConfig the current project config
-     * @param eventName the event type to retrieve from the current project config
-     * @return the event type for the given event name
-     *
-     * @throws UnknownEventTypeException if there are no event types in the current project config with the given name
-     */
-    private EventType getEventTypeOrThrow(ProjectConfig projectConfig, String eventName)
-        throws UnknownEventTypeException {
-
-        EventType eventType = projectConfig
-            .getEventNameMapping()
-            .get(eventName);
-
-        // if the given event name isn't present in the config, log and potentially throw an exception
-        if (eventType == null) {
-            String unknownEventTypeError = String.format("Event \"%s\" is not in the datafile.", eventName);
-            logger.error(unknownEventTypeError);
-            errorHandler.handleError(new UnknownEventTypeException(unknownEventTypeError));
-        }
-
-        return eventType;
-    }
-
     /**
      * Helper method to verify that the given attributes map contains only keys that are present in the
      * {@link ProjectConfig}.

core-api/src/main/java/com/optimizely/ab/config/ProjectConfig.java

@@ -17,11 +17,17 @@
 package com.optimizely.ab.config;
 
 import com.fasterxml.jackson.annotation.JsonIgnoreProperties;
+import com.optimizely.ab.UnknownEventTypeException;
+import com.optimizely.ab.UnknownExperimentException;
 import com.optimizely.ab.config.audience.Audience;
 import com.optimizely.ab.config.audience.Condition;
+import com.optimizely.ab.error.ErrorHandler;
+import com.optimizely.ab.error.NoOpErrorHandler;
+import com.optimizely.ab.error.RaiseExceptionErrorHandler;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
+import javax.annotation.CheckForNull;
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 import javax.annotation.concurrent.Immutable;
@@ -210,6 +216,62 @@ public ProjectConfig(String accountId,
         }
     }
 
+    /**
+     * Helper method to retrieve the {@link Experiment} for the given experiment key.
+     * If {@link RaiseExceptionErrorHandler} is provided, either an experiment is returned,
+     *  or an exception is sent to the error handler
+     *  if there are no experiments in the project config with the given experiment key.
+     * If {@link NoOpErrorHandler} is used, either an experiment or {@code null} is returned.
+     *
+     * @param experimentKey the experiment to retrieve from the current project config
+     * @param errorHandler the error handler to send exceptions to
+     * @return the experiment for given experiment key
+     */
+    @CheckForNull
+    public Experiment getExperimentForKey(@Nonnull String experimentKey,
+                                          @Nonnull ErrorHandler errorHandler) {
+
+        Experiment experiment =
+                getExperimentKeyMapping()
+                        .get(experimentKey);
+
+        // if the given experiment key isn't present in the config, log an exception to the error handler
+        if (experiment == null) {
+            String unknownExperimentError = String.format("Experiment \"%s\" is not in the datafile.", experimentKey);
+            logger.error(unknownExperimentError);
+            errorHandler.handleError(new UnknownExperimentException(unknownExperimentError));
+        }
+
+        return experiment;
+    }
+
+    /**
+     * Helper method to retrieve the {@link EventType} for the given event name.
+     * If {@link RaiseExceptionErrorHandler} is provided, either an event type is returned,
+     *  or an exception is sent to the error handler if there are no event types in the project config with the given name.
+     * If {@link NoOpErrorHandler} is used, either an event type or {@code null} is returned.
+     *
+     * @param eventName the event type to retrieve from the current project config
+     * @param errorHandler the error handler to send exceptions to
+     * @return the event type for the given event name
+     */
+    public @CheckForNull EventType getEventTypeForName(String eventName, ErrorHandler errorHandler) {
+
+        EventType eventType =
+                getEventNameMapping()
+                        .get(eventName);
+
+        // if the given event name isn't present in the config, log an exception to the error handler
+        if (eventType == null) {
+            String unknownEventTypeError = String.format("Event \"%s\" is not in the datafile.", eventName);
+            logger.error(unknownEventTypeError);
+            errorHandler.handleError(new UnknownEventTypeException(unknownEventTypeError));
+        }
+
+        return eventType;
+    }
+
+
     public @Nullable Experiment getExperimentForVariationId(String variationId) {
         return this.variationIdToExperimentMapping.get(variationId);
     }