Adds a hasAttribute() method to Retrievable.

Signed-off-by: Ralph Gasser <[email protected]>

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/AbstractRetrievable.kt

@@ -4,25 +4,30 @@ import org.vitrivr.engine.core.model.retrievable.attributes.MergingRetrievableAt
 import org.vitrivr.engine.core.model.retrievable.attributes.RetrievableAttribute
 import java.util.*
 
+/**
+ * An abstract implementation of a [Retrievable] implementing basic logic to manage [RetrievableAttribute]s.
+ *
+ * @author Luca Rossetto
+ * @author Ralph Gasser
+ * @version 1.1.0
+ */
 abstract class AbstractRetrievable(override val id: UUID, override val type: String?, override val transient: Boolean) : Retrievable {
 
     constructor(retrievable: Retrievable) : this(retrievable.id, retrievable.type, retrievable.transient) {
         retrievable.attributes.forEach { this.addAttribute(it) }
     }
 
     private val attributeSet = mutableSetOf<RetrievableAttribute>()
+
+    /** [Collection] of [RetrievableAttribute]s held by this [AbstractRetrievable]. */
     override val attributes: Collection<RetrievableAttribute>
         get() = this.attributeSet
 
-    override fun <T : RetrievableAttribute> filteredAttributes(c: Class<T>): Collection<T> = this.attributeSet.filterIsInstance(c)
-
-    inline fun <reified T : RetrievableAttribute> filteredAttributes(): Collection<T> = filteredAttributes(T::class.java)
-
-    @Suppress("UNCHECKED_CAST")
-    override fun <T : RetrievableAttribute> filteredAttribute(c: Class<T>): T? = attributeSet.firstOrNull { c.isInstance(it) } as? T
-
-    inline fun <reified T : RetrievableAttribute> filteredAttribute(): T? = filteredAttribute(T::class.java)
-
+    /**
+     * Adds a [RetrievableAttribute] to this [AbstractRetrievable].
+     *
+     * @param attribute The [RetrievableAttribute] to add.
+     */
     override fun addAttribute(attribute: RetrievableAttribute) {
         if (this.attributeSet.contains(attribute)) {
             return
@@ -41,8 +46,40 @@ abstract class AbstractRetrievable(override val id: UUID, override val type: Str
         }
     }
 
+    /**
+     * Removes all [RetrievableAttribute]s  of a certain type from this [AbstractRetrievable].
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to remove.
+     */
     override fun <T : RetrievableAttribute> removeAttributes(c: Class<T>) {
         this.attributeSet.removeIf { c.isInstance(it) }
     }
 
+    /**
+     * Checks if this [Retrievable] has a [RetrievableAttribute] of the given type.
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to check for.
+     * @return True, if [RetrievableAttribute]
+     */
+    override fun <T : RetrievableAttribute> hasAttribute(c: Class<T>): Boolean = this.attributeSet.any { c.isInstance(it) }
+
+    /**
+     * Returns all [RetrievableAttribute] of a certain type.
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to return.
+     * @return [Collection] of [RetrievableAttribute]s.
+     */
+    override fun <T : RetrievableAttribute> filteredAttributes(c: Class<T>): Collection<T> = this.attributeSet.filterIsInstance(c)
+
+    inline fun <reified T : RetrievableAttribute> filteredAttributes(): Collection<T> = filteredAttributes(T::class.java)
+
+    /**
+     * Returns the first [RetrievableAttribute] of a certain type.
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to return.
+     * @return [RetrievableAttribute] or null.
+     */
+    override fun <T : RetrievableAttribute> filteredAttribute(c: Class<T>): T? = this.attributeSet.filterIsInstance(c).firstOrNull()
+
+    inline fun <reified T : RetrievableAttribute> filteredAttribute(): T? = filteredAttribute(T::class.java)
 }

vitrivr-engine-core/src/main/kotlin/org/vitrivr/engine/core/model/retrievable/Retrievable.kt

@@ -12,7 +12,7 @@ typealias RetrievableId = UUID
  *
  * @author Luca Rossetto
  * @author Ralph Gasser
- * @version 1.0.0
+ * @version 1.1.0
  */
 interface Retrievable : Persistable {
     /** The [RetrievableId] held by this [Retrievable]. */
@@ -21,19 +21,44 @@ interface Retrievable : Persistable {
     /** The type of this [Retrievable]. This is basically a string that can help to keep apart different types of [Retrievable]. */
     val type: String?
 
-    /**
-     * The attributes of this retrievable
-     */
+    /** The attributes of this retrievable */
     val attributes: Collection<RetrievableAttribute>
 
     /**
-     * Returns only attributes of a certain type
+     * Checks if this [Retrievable] has a [RetrievableAttribute] of the given type.
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to check for.
+     * @return True, if [RetrievableAttribute]
      */
-    fun <T : RetrievableAttribute> filteredAttributes(c: Class<T>): Collection<T>
-
-    fun <T : RetrievableAttribute> filteredAttribute(c: Class<T>): T?
+    fun <T : RetrievableAttribute> hasAttribute(c: Class<T>): Boolean
 
+    /**
+     * Adds a [RetrievableAttribute] to this [Retrievable].
+     *
+     * @param attribute The [RetrievableAttribute] to add.
+     */
     fun addAttribute(attribute: RetrievableAttribute)
 
+    /**
+     * Removes all [RetrievableAttribute]s  of a certain type from this [Retrievable].
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to remove.
+     */
     fun <T : RetrievableAttribute> removeAttributes(c: Class<T>)
+
+    /**
+     * Returns all [RetrievableAttribute] of a certain type.
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to return.
+     * @return [Collection] of [RetrievableAttribute]s.
+     */
+    fun <T : RetrievableAttribute> filteredAttributes(c: Class<T>): Collection<T>
+
+    /**
+     * Returns the first [RetrievableAttribute] of a certain type.
+     *
+     * @param c The [Class] of the [RetrievableAttribute] to return.
+     * @return [RetrievableAttribute] or null.
+     */
+    fun <T : RetrievableAttribute> filteredAttribute(c: Class<T>): T?
 }