Merge pull request #918 from jeffgbutler/kotlin-example

Add a Kotlin example of a custom condition

Author: jeffgbutler

src/main/java/org/mybatis/dynamic/sql/where/condition/CaseInsensitiveVisitableCondition.java src/main/java/org/mybatis/dynamic/sql/where/condition/CaseInsensitiveRenderableCondition.java

@@ -20,7 +20,7 @@
 import org.mybatis.dynamic.sql.render.RenderingContext;
 import org.mybatis.dynamic.sql.util.FragmentAndParameters;
 
-public interface CaseInsensitiveVisitableCondition extends RenderableCondition<String> {
+public interface CaseInsensitiveRenderableCondition extends RenderableCondition<String> {
 
     @Override
     default FragmentAndParameters renderLeftColumn(RenderingContext renderingContext,

src/main/java/org/mybatis/dynamic/sql/where/condition/IsInCaseInsensitive.java

@@ -27,7 +27,7 @@
 import org.mybatis.dynamic.sql.util.Validator;
 
 public class IsInCaseInsensitive extends AbstractListValueCondition<String>
-        implements CaseInsensitiveVisitableCondition {
+        implements CaseInsensitiveRenderableCondition {
     private static final IsInCaseInsensitive EMPTY = new IsInCaseInsensitive(Collections.emptyList());
 
     public static IsInCaseInsensitive empty() {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsInCaseInsensitiveWhenPresent.java

@@ -27,7 +27,7 @@
 import org.mybatis.dynamic.sql.util.Utilities;
 
 public class IsInCaseInsensitiveWhenPresent extends AbstractListValueCondition<String>
-        implements CaseInsensitiveVisitableCondition {
+        implements CaseInsensitiveRenderableCondition {
     private static final IsInCaseInsensitiveWhenPresent EMPTY =
             new IsInCaseInsensitiveWhenPresent(Collections.emptyList());
 

src/main/java/org/mybatis/dynamic/sql/where/condition/IsLikeCaseInsensitive.java

@@ -23,7 +23,7 @@
 import org.mybatis.dynamic.sql.util.StringUtilities;
 
 public class IsLikeCaseInsensitive extends AbstractSingleValueCondition<String>
-        implements CaseInsensitiveVisitableCondition {
+        implements CaseInsensitiveRenderableCondition {
     private static final IsLikeCaseInsensitive EMPTY = new IsLikeCaseInsensitive("") { //$NON-NLS-1$
         @Override
         public String value() {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsNotInCaseInsensitive.java

@@ -27,7 +27,7 @@
 import org.mybatis.dynamic.sql.util.Validator;
 
 public class IsNotInCaseInsensitive extends AbstractListValueCondition<String>
-        implements CaseInsensitiveVisitableCondition {
+        implements CaseInsensitiveRenderableCondition {
     private static final IsNotInCaseInsensitive EMPTY = new IsNotInCaseInsensitive(Collections.emptyList());
 
     public static IsNotInCaseInsensitive empty() {

src/main/java/org/mybatis/dynamic/sql/where/condition/IsNotInCaseInsensitiveWhenPresent.java

@@ -27,7 +27,7 @@
 import org.mybatis.dynamic.sql.util.Utilities;
 
 public class IsNotInCaseInsensitiveWhenPresent extends AbstractListValueCondition<String>
-        implements CaseInsensitiveVisitableCondition {
+        implements CaseInsensitiveRenderableCondition {
     private static final IsNotInCaseInsensitiveWhenPresent EMPTY =
             new IsNotInCaseInsensitiveWhenPresent(Collections.emptyList());
 

src/main/java/org/mybatis/dynamic/sql/where/condition/IsNotLikeCaseInsensitive.java

@@ -23,7 +23,7 @@
 import org.mybatis.dynamic.sql.util.StringUtilities;
 
 public class IsNotLikeCaseInsensitive extends AbstractSingleValueCondition<String>
-        implements CaseInsensitiveVisitableCondition {
+        implements CaseInsensitiveRenderableCondition {
     private static final IsNotLikeCaseInsensitive EMPTY = new IsNotLikeCaseInsensitive("") { //$NON-NLS-1$
         @Override
         public String value() {

src/main/kotlin/org/mybatis/dynamic/sql/util/kotlin/GroupingCriteriaCollector.kt

@@ -235,8 +235,8 @@ open class GroupingCriteriaCollector : SubCriteriaCollector() {
             .build()
     }
 
-    // infix functions...we may be able to rewrite these as extension functions once Kotlin solves the multiple
-    // receivers problem (https://youtrack.jetbrains.com/issue/KT-42435)
+    // infix functions...we may be able to rewrite these as extension functions once Kotlin implements the context
+    // parameters proposal (https://github.com/Kotlin/KEEP/issues/367)
 
     // conditions for all data types
     fun BindableColumn<*>.isNull() = invoke(org.mybatis.dynamic.sql.util.kotlin.elements.isNull())

src/test/kotlin/examples/kotlin/mybatis3/mariadb/KIsLikeEscape.kt

@@ -0,0 +1,54 @@
+package examples.kotlin.mybatis3.mariadb
+
+import java.util.function.Predicate
+import java.util.function.Function
+import org.mybatis.dynamic.sql.AbstractSingleValueCondition
+import org.mybatis.dynamic.sql.BindableColumn
+import org.mybatis.dynamic.sql.render.RenderingContext
+import org.mybatis.dynamic.sql.util.FragmentAndParameters
+
+sealed class KIsLikeEscape<T : Any>(
+    value: T,
+    private val escapeCharacter: Char? = null
+) : AbstractSingleValueCondition<T>(value) {
+
+    override fun operator(): String = "like"
+
+    override fun renderCondition(
+        renderingContext: RenderingContext,
+        leftColumn: BindableColumn<T>
+    ): FragmentAndParameters = with(super.renderCondition(renderingContext, leftColumn)) {
+        escapeCharacter?.let { mapFragment { "$it ESCAPE '$escapeCharacter'" } } ?: this
+    }
+
+    override fun filter(predicate: Predicate<in T>): KIsLikeEscape<T> =
+        filterSupport(predicate, EmptyIsLikeEscape::empty, this)
+
+    fun <R : Any> map(mapper : Function<in T, out R>): KIsLikeEscape<R> =
+        mapSupport(mapper, { r -> ConcreteIsLikeEscape(r, escapeCharacter) }, EmptyIsLikeEscape::empty)
+
+    companion object {
+        fun <T: Any> isLike(value: T, escapeCharacter: Char? = null) : KIsLikeEscape<T> =
+            ConcreteIsLikeEscape(value, escapeCharacter)
+    }
+}
+
+private class ConcreteIsLikeEscape<T: Any>(
+    value: T,
+    escapeCharacter: Char? = null
+) : KIsLikeEscape<T>(value, escapeCharacter)
+
+private class EmptyIsLikeEscape : KIsLikeEscape<Any>(-1) {
+    override fun isEmpty(): Boolean = true
+
+    override fun value(): Any {
+        throw NoSuchElementException("No value present")
+    }
+
+    companion object {
+        private val EMPTY: KIsLikeEscape<Any> = EmptyIsLikeEscape()
+
+        @Suppress("UNCHECKED_CAST")
+        internal fun <T : Any> empty(): KIsLikeEscape<T> = EMPTY as KIsLikeEscape<T>
+    }
+}

src/test/kotlin/examples/kotlin/mybatis3/mariadb/KMariaDBTest.kt

@@ -38,6 +38,7 @@ import org.mybatis.dynamic.sql.util.mybatis3.CommonUpdateMapper
 import org.testcontainers.containers.MariaDBContainer
 import org.testcontainers.junit.jupiter.Container
 import org.testcontainers.junit.jupiter.Testcontainers
+import java.util.Locale
 
 @Testcontainers
 @TestInstance(TestInstance.Lifecycle.PER_CLASS)
@@ -142,6 +143,92 @@ class KMariaDBTest {
         }
     }
 
+
+    /**
+     * Shortcut function for KIsLikeEscape
+     *
+     * Note that the following example uses of this function are a bit awkward and don't look as natural as the
+     * built-in conditions. We should be able to improve this once Kotlin implements the context parameters
+     * proposal (https://github.com/Kotlin/KEEP/issues/367)
+     */
+    fun <T : Any> isLike(value: T, escapeCharacter: Char? = null) = KIsLikeEscape.isLike(value, escapeCharacter)
+
+    @Test
+    fun testIsLikeEscape() {
+        sqlSessionFactory.openSession().use { session ->
+            val mapper = session.getMapper(CommonSelectMapper::class.java)
+            val selectStatement = select(id, description) {
+                from(items)
+                where {
+                    description(isLike("Item 1%", '#'))
+                }
+            }
+
+            assertThat(selectStatement.selectStatement).isEqualTo("select id, description from items where description like #{parameters.p1,jdbcType=VARCHAR} ESCAPE '#'")
+            assertThat(selectStatement.parameters).containsEntry("p1", "Item 1%")
+
+            val rows = mapper.selectManyMappedRows(selectStatement)
+            assertThat(rows).hasSize(11)
+        }
+    }
+
+    @Test
+    fun testIsLikeEscapeNoEscapeCharacter() {
+        val selectStatement = select(id, description) {
+            from(items)
+            where {
+                description(isLike("%fred%"))
+            }
+        }
+
+        assertThat(selectStatement.selectStatement).isEqualTo("select id, description from items where description like #{parameters.p1,jdbcType=VARCHAR}")
+        assertThat(selectStatement.parameters).containsEntry("p1", "%fred%")
+    }
+
+    @Test
+    fun testIsLikeEscapeMap() {
+        val selectStatement = select(id, description) {
+            from(items)
+            where {
+                description(isLike("%fred%", '#').map { s -> s.uppercase(Locale.getDefault()) })
+            }
+        }
+
+        assertThat(selectStatement.selectStatement).isEqualTo("select id, description from items where description like #{parameters.p1,jdbcType=VARCHAR} ESCAPE '#'")
+        assertThat(selectStatement.parameters).containsEntry("p1", "%FRED%")
+    }
+
+    @Test
+    fun testIsLikeEscapeFilter() {
+        val selectStatement = select(id, description) {
+            from(items)
+            where {
+                description(isLike("%fred%", '#').filter { _ -> false })
+            }
+            configureStatement { isNonRenderingWhereClauseAllowed = true }
+        }
+
+        assertThat(selectStatement.selectStatement).isEqualTo("select id, description from items")
+        assertThat(selectStatement.parameters).isEmpty()
+    }
+
+    @Test
+    fun testIsLikeEscapeFilterMapFilter() {
+        val selectStatement = select(id, description) {
+            from(items)
+            where {
+                description(isLike("%fred%", '#')
+                    .filter { _ -> true }
+                    .map { s -> s.uppercase(Locale.getDefault()) }
+                    .filter{_ -> false })
+            }
+            configureStatement { isNonRenderingWhereClauseAllowed = true }
+        }
+
+        assertThat(selectStatement.selectStatement).isEqualTo("select id, description from items")
+        assertThat(selectStatement.parameters).isEmpty()
+    }
+
     companion object {
         @Container
         private val mariadb = MariaDBContainer(TestContainersConfiguration.MARIADB_LATEST)