feat: Support transient identities and traits (#158)

Author: khvn26

src/main/java/com/flagsmith/FlagsmithApiWrapper.java

@@ -172,33 +172,36 @@ public Flags getFeatureFlags(boolean doThrow) {
 
   @Override
   public Flags identifyUserWithTraits(
-      String identifier, List<TraitModel> traits, boolean doThrow
+      String identifier, List<? extends TraitModel> traits, boolean isTransient, boolean doThrow
   ) {
     assertValidUser(identifier);
     Flags flags = null;
     String cacheKey = null;
 
     if (getCache() != null) {
-      cacheKey = getCache().getIdentityFlagsCacheKey(identifier);
+      cacheKey = getCache().getIdentityFlagsCacheKey(identifier, isTransient);
       flags = getCache().getIfPresent(cacheKey);
 
       if (flags != null) {
         return flags;
       }
     }
 
-    // we are using identities endpoint to create bulk user Trait
-    HttpUrl url = defaultConfig.getIdentitiesUri();
-
     ObjectNode node = MapperFactory.getMapper().createObjectNode();
     node.put("identifier", identifier);
 
+    if (isTransient) {
+      node.put("transient", true);
+    }
+
     if (traits != null) {
       node.putPOJO("traits", traits);
     }
 
     MediaType json = MediaType.parse("application/json; charset=utf-8");
-    RequestBody body = RequestBody.create(json, node.toString());
+    RequestBody body = RequestBody.create(node.toString(), json);
+
+    HttpUrl url = defaultConfig.getIdentitiesUri();
 
     final Request request = this.newPostRequest(url, body);
 

src/main/java/com/flagsmith/FlagsmithClient.java

@@ -16,8 +16,11 @@
 import com.flagsmith.interfaces.FlagsmithSdk;
 import com.flagsmith.models.BaseFlag;
 import com.flagsmith.models.Flags;
+import com.flagsmith.models.SdkTraitModel;
 import com.flagsmith.models.Segment;
 import com.flagsmith.threads.PollingManager;
+import com.flagsmith.utils.ModelUtils;
+import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.List;
 import java.util.Map;
@@ -78,6 +81,11 @@ public void updateEnvironment() {
 
   /**
    * Get all the default for flags for the current environment.
+   * <<<<<<< HEAD
+   * =======
+   *
+   * @return environment flags
+   *         >>>>>>> a7a9291 (feat: Support transient identities and traits)
    */
   public Flags getEnvironmentFlags() throws FlagsmithClientError {
     if (getShouldUseEnvironmentDocument()) {
@@ -88,12 +96,13 @@ public Flags getEnvironmentFlags() throws FlagsmithClientError {
   }
 
   /**
-   * Get all the flags for the current environment for a given identity. Will also
-   * upsert all traits to the Flagsmith API for future evaluations. Providing a
-   * trait with a value of None will remove the trait from the identity if it
-   * exists.
+   * Get all the flags for the current environment for a given identity.
    *
    * @param identifier identifier string
+   *                   <<<<<<< HEAD
+   *                   =======
+   * @return result of flag evaluation for given identity
+   *         >>>>>>> a7a9291 (feat: Support transient identities and traits)
    */
   public Flags getIdentityFlags(String identifier)
       throws FlagsmithClientError {
@@ -102,20 +111,58 @@ public Flags getIdentityFlags(String identifier)
 
   /**
    * Get all the flags for the current environment for a given identity. Will also
-   * upsert all traits to the Flagsmith API for future evaluations. Providing a
-   * trait with a value of None will remove the trait from the identity if it
+   * upsert traits to the Flagsmith API for future evaluations.
+   * 
+   * <p>
+   * A trait with a value of null will remove the trait from the identity if it
    * exists.
+   * </p>
+   * <p>
+   * To specify a transient trait, use the TraitConfig class with isTransient set
+   * to true as the trait value.
+   * </p>
    *
+   * @see com.flagsmith.models.TraitConfig
+   * 
    * @param identifier identifier string
-   * @param traits     list of key value traits
+   * @param traits     a map of trait keys to trait values
    */
   public Flags getIdentityFlags(String identifier, Map<String, Object> traits)
       throws FlagsmithClientError {
+    return getIdentityFlags(identifier, traits, false);
+  }
+
+  /**
+   * Get all the flags for the current environment for a given identity. Will also
+   * upsert traits to the Flagsmith API for future evaluations, if isTransient set
+   * to false.
+   * 
+   * <p>
+   * A trait with a value of null will remove the trait from the identity if it
+   * exists.
+   * </p>
+   * <p>
+   * To specify a transient trait, use the TraitConfig class with isTransient set
+   * to true as the trait value.
+   * </p>
+   *
+   * @see com.flagsmith.models.TraitConfig
+   * 
+   * @param identifier  identifier string
+   * @param traits      a map of trait keys to trait values
+   * @param isTransient set to true to prevent identity persistence
+   * @return result of flag evaluation for given identity
+   */
+  public Flags getIdentityFlags(String identifier, Map<String, Object> traits, boolean isTransient)
+      throws FlagsmithClientError {
     if (getShouldUseEnvironmentDocument()) {
-      return getIdentityFlagsFromDocument(identifier, traits);
+      return getIdentityFlagsFromDocument(
+          identifier,
+          ModelUtils.getTraitModelsFromTraitMap(traits));
     }
 
-    return getIdentityFlagsFromApi(identifier, traits);
+    return getIdentityFlagsFromApi(
+        identifier, ModelUtils.getSdkTraitModelsFromTraitMap(traits), isTransient);
   }
 
   /**
@@ -143,7 +190,10 @@ public List<Segment> getIdentitySegments(String identifier, Map<String, Object>
       throw new FlagsmithClientError("Local evaluation required to obtain identity segments.");
     }
     IdentityModel identityModel = getIdentityModel(
-        identifier, (traits != null ? traits : new HashMap<>()));
+        identifier,
+        (traits != null
+            ? ModelUtils.getTraitModelsFromTraitMap(traits)
+            : new ArrayList<TraitModel>()));
     List<SegmentModel> segmentModels = SegmentEvaluator.getIdentitySegments(
         environment, identityModel);
 
@@ -182,7 +232,8 @@ private Flags getEnvironmentFlagsFromDocument() throws FlagsmithClientError {
         getConfig().getFlagsmithFlagDefaults());
   }
 
-  private Flags getIdentityFlagsFromDocument(String identifier, Map<String, Object> traits)
+  private Flags getIdentityFlagsFromDocument(
+      String identifier, List<? extends TraitModel> traitModels)
       throws FlagsmithClientError {
     if (environment == null) {
       if (getConfig().getFlagsmithFlagDefaults() == null) {
@@ -191,7 +242,7 @@ private Flags getIdentityFlagsFromDocument(String identifier, Map<String, Object
       return getDefaultFlags();
     }
 
-    IdentityModel identity = getIdentityModel(identifier, traits);
+    IdentityModel identity = getIdentityModel(identifier, traitModels);
     List<FeatureStateModel> featureStates = Engine.getIdentityFeatureStates(environment, identity);
 
     return Flags.fromFeatureStateModels(
@@ -219,27 +270,21 @@ private Flags getEnvironmentFlagsFromApi() throws FlagsmithApiError {
     }
   }
 
-  private Flags getIdentityFlagsFromApi(String identifier, Map<String, Object> traits)
+  private Flags getIdentityFlagsFromApi(
+      String identifier, List<SdkTraitModel> traitModels, boolean isTransient)
       throws FlagsmithApiError {
     try {
-      List<TraitModel> traitsList = traits.entrySet().stream().map((row) -> {
-        TraitModel trait = new TraitModel();
-        trait.setTraitValue(row.getValue());
-        trait.setTraitKey(row.getKey());
-
-        return trait;
-      }).collect(Collectors.toList());
-
       return flagsmithSdk.identifyUserWithTraits(
           identifier,
-          traitsList,
+          traitModels,
+          isTransient,
           Boolean.TRUE);
     } catch (Exception e) {
       if (getConfig().getFlagsmithFlagDefaults() != null) {
         return getDefaultFlags();
       } else if (environment != null) {
         try {
-          return getIdentityFlagsFromDocument(identifier, traits);
+          return getIdentityFlagsFromDocument(identifier, traitModels);
         } catch (FlagsmithClientError ce) {
           // Do nothing and fall through to FlagsmithApiError
         }
@@ -249,31 +294,23 @@ private Flags getIdentityFlagsFromApi(String identifier, Map<String, Object> tra
     }
   }
 
-  private IdentityModel getIdentityModel(String identifier, Map<String, Object> traits)
+  private IdentityModel getIdentityModel(String identifier, List<? extends TraitModel> traitModels)
       throws FlagsmithClientError {
     if (environment == null) {
       throw new FlagsmithClientError(
           "Unable to build identity model when no local environment present.");
     }
 
-    List<TraitModel> traitsList = traits.entrySet().stream().map((entry) -> {
-      TraitModel trait = new TraitModel();
-      trait.setTraitKey(entry.getKey());
-      trait.setTraitValue(entry.getValue());
-
-      return trait;
-    }).collect(Collectors.toList());
-
     if (identitiesWithOverridesByIdentifier != null) {
       IdentityModel identityOverride = identitiesWithOverridesByIdentifier.get(identifier);
       if (identityOverride != null) {
-        identityOverride.updateTraits(traitsList);
+        identityOverride.updateTraits(traitModels);
         return identityOverride;
       }
     }
 
     IdentityModel identity = new IdentityModel();
-    identity.setIdentityTraits(traitsList);
+    identity.setIdentityTraits(traitModels);
     identity.setEnvironmentApiKey(environment.getApiKey());
     identity.setIdentifier(identifier);
 
@@ -289,7 +326,7 @@ private Flags getDefaultFlags() {
   private String getEnvironmentUpdateErrorMessage() {
     if (this.environment == null) {
       return "Unable to update environment from API. "
-        + "No environment configured - using defaultHandler if configured.";
+          + "No environment configured - using defaultHandler if configured.";
     } else {
       return "Unable to update environment from API. Continuing to use previous copy.";
     }
@@ -541,7 +578,7 @@ public FlagsmithClient build() {
       if (configuration.getOfflineHandler() != null) {
         if (configuration.getFlagsmithFlagDefaults() != null) {
           throw new FlagsmithRuntimeError(
-            "Cannot use both default flag handler and offline handler.");
+              "Cannot use both default flag handler and offline handler.");
         }
         client.environment = configuration.getOfflineHandler().getEnvironment();
       }

src/main/java/com/flagsmith/config/FlagsmithCacheConfig.java

@@ -206,8 +206,8 @@ public String getEnvFlagsCacheKey() {
     }
 
     @Override
-    public String getIdentityFlagsCacheKey(String identifier) {
-      return "identity" + identifier;
+    public String getIdentityFlagsCacheKey(String identifier, boolean isTransient) {
+      return "identity" + identifier + (isTransient ? "transient" : "");
     }
 
     @Override

src/main/java/com/flagsmith/flagengine/identities/IdentityModel.java

@@ -27,7 +27,7 @@ public class IdentityModel extends BaseModel {
   @JsonProperty("identity_uuid")
   private String identityUuid = UUID.randomUUID().toString();
   @JsonProperty("identity_traits")
-  private List<TraitModel> identityTraits = new ArrayList<>();
+  private List<? extends TraitModel> identityTraits = new ArrayList<>();
   @JsonProperty("identity_features")
   private List<FeatureStateModel> identityFeatures = new ArrayList<>();
   @JsonProperty("composite_key")
@@ -48,7 +48,7 @@ public String getCompositeKey() {
    *
    * @param traits traits to update
    */
-  public void updateTraits(List<TraitModel> traits) {
+  public void updateTraits(List<? extends TraitModel> traits) {
     Map<String, TraitModel> existingTraits = new HashMap<>();
 
     if (identityTraits != null && identityTraits.size() > 0) {

src/main/java/com/flagsmith/flagengine/identities/traits/TraitModel.java

@@ -4,10 +4,12 @@
 import lombok.AllArgsConstructor;
 import lombok.Data;
 import lombok.NoArgsConstructor;
+import lombok.experimental.SuperBuilder;
 
 @Data
 @NoArgsConstructor
 @AllArgsConstructor
+@SuperBuilder
 public class TraitModel {
   @JsonProperty("trait_key")
   private String traitKey;

src/main/java/com/flagsmith/flagengine/segments/SegmentEvaluator.java

@@ -51,9 +51,9 @@ public static List<SegmentModel> getIdentitySegments(EnvironmentModel environmen
    * @param overrideTraits Overriden traits.
    */
   public static Boolean evaluateIdentityInSegment(IdentityModel identity, SegmentModel segment,
-                                                  List<TraitModel> overrideTraits) {
+                                                  List<? extends TraitModel> overrideTraits) {
     List<SegmentRuleModel> segmentRules = segment.getRules();
-    List<TraitModel> traits =
+    List<? extends TraitModel> traits =
         overrideTraits != null ? overrideTraits : identity.getIdentityTraits();
 
     String identityHashKey = identity.getDjangoId() == null ? identity.getCompositeKey()
@@ -83,7 +83,7 @@ public static Boolean evaluateIdentityInSegment(IdentityModel identity, SegmentM
    * @param segmentId Segment ID (for hashing)
    * @param identityId Identity ID (for hashing)
    */
-  private static Boolean traitsMatchSegmentRule(List<TraitModel> identityTraits,
+  private static Boolean traitsMatchSegmentRule(List<? extends TraitModel> identityTraits,
                                                 SegmentRuleModel rule,
                                                 Integer segmentId, String identityId) {
     Boolean matchingCondition = Boolean.TRUE;
@@ -122,7 +122,7 @@ private static Boolean traitsMatchSegmentRule(List<TraitModel> identityTraits,
    * @param segmentId Segment ID (for hashing)
    * @param identityId Identity ID (for hashing)
    */
-  private static Boolean traitsMatchSegmentCondition(List<TraitModel> identityTraits,
+  private static Boolean traitsMatchSegmentCondition(List<? extends TraitModel> identityTraits,
                                                      SegmentConditionModel condition,
                                                      Integer segmentId, String identityId) {
     if (condition.getOperator().equals(SegmentConditions.PERCENTAGE_SPLIT)) {
@@ -137,7 +137,7 @@ private static Boolean traitsMatchSegmentCondition(List<TraitModel> identityTrai
     }
 
     if (identityTraits != null) {
-      Optional<TraitModel> matchingTrait = identityTraits
+      Optional<? extends TraitModel> matchingTrait = identityTraits
           .stream()
           .filter((trait) -> trait.getTraitKey().equals(condition.getProperty_()))
           .findFirst();
@@ -154,7 +154,7 @@ private static Boolean traitsMatchSegmentCondition(List<TraitModel> identityTrai
    * @param trait Trait to match against.
    * @param condition Condition to evaluate with.
    */
-  private static Boolean traitMatchesSegmentCondition(Optional<TraitModel> trait,
+  private static Boolean traitMatchesSegmentCondition(Optional<? extends TraitModel> trait,
                                                       SegmentConditionModel condition) {
     if (condition.getOperator().equals(SegmentConditions.IS_NOT_SET)) {
       return !trait.isPresent();

src/main/java/com/flagsmith/interfaces/FlagsmithCache.java

@@ -72,7 +72,7 @@ public interface FlagsmithCache {
    *
    * @return string
    */
-  String getIdentityFlagsCacheKey(String identifier);
+  String getIdentityFlagsCacheKey(String identifier, boolean isTransient);
 
   /**
    * Returns the Cache instance.

src/main/java/com/flagsmith/interfaces/FlagsmithSdk.java

@@ -16,7 +16,7 @@ public interface FlagsmithSdk {
   Flags getFeatureFlags(boolean doThrow);
 
   Flags identifyUserWithTraits(
-      String identifier, List<TraitModel> traits, boolean doThrow
+      String identifier, List<? extends TraitModel> traits, boolean isTransient, boolean doThrow
   );
 
   FlagsmithConfig getConfig();

src/main/java/com/flagsmith/models/SdkTraitModel.java

@@ -0,0 +1,22 @@
+package com.flagsmith.models;
+
+import com.fasterxml.jackson.annotation.JsonInclude;
+import com.fasterxml.jackson.annotation.JsonInclude.Include;
+import com.fasterxml.jackson.annotation.JsonProperty;
+import com.flagsmith.flagengine.identities.traits.TraitModel;
+import lombok.Builder;
+import lombok.Data;
+import lombok.EqualsAndHashCode;
+import lombok.NoArgsConstructor;
+import lombok.experimental.SuperBuilder;
+
+@Data
+@SuperBuilder
+@NoArgsConstructor
+@EqualsAndHashCode(callSuper = true)
+@JsonInclude(Include.NON_DEFAULT)
+public class SdkTraitModel extends TraitModel {
+  @JsonProperty("transient")
+  @Builder.Default
+  private Boolean isTransient = false;
+}