feat(databinding): Add a New ValueConverter for LocalDateTime (#13351)

* add default data binding support for local date time

* local date time class

* Rename class FormattedLocalDateValueConverter

* feat(databinding): Add a New ValueConverter for LocalDateTime

Adds a new converter named `LocalDateTimeConverter` which will automatically convert `String` or `LocalDateTime` values when using data binder.

Fixes #13280

* update test

---------

Co-authored-by: Emma Richardson <49138186+Emrichardsone@users.noreply.github.com>
Co-authored-by: Puneet Behl <behlp@unityfoundation.io>

grails-databinding/src/main/groovy/org/grails/databinding/converters/FormattedLocalDateTimeValueConverter.groovy

@@ -0,0 +1,49 @@
+/*
+ * Copyright 2013 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.grails.databinding.converters
+
+import grails.databinding.converters.FormattedValueConverter;
+import groovy.transform.CompileStatic
+
+import java.time.LocalDateTime
+
+/**
+ * @author Emma Richardson
+ * @since 6.1
+ */
+@CompileStatic
+class FormattedLocalDateTimeValueConverter implements FormattedValueConverter {
+
+    def convert(value, String format) {
+        if(value instanceof LocalDateTime) {
+            return value
+        }
+        else if(value instanceof CharSequence) {
+            String dateStr = value.toString()
+            if(!dateStr) {
+                return null
+            }
+            else {
+                LocalDateTime.parse((String) value)
+            }
+        }
+    }
+
+    @Override
+    Class<?> getTargetType() {
+        return LocalDateTime
+    }
+}

grails-databinding/src/main/groovy/org/grails/databinding/converters/LocalDateTimeConverter.groovy

@@ -0,0 +1,54 @@
+/*
+ * Copyright 2024 the original author or authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package org.grails.databinding.converters
+
+import grails.databinding.converters.ValueConverter
+import groovy.transform.CompileStatic
+
+import java.time.LocalDateTime
+
+/**
+ * This class is a {@link ValueConverter} for {@link LocalDateTime} target type.
+ *
+ * @author Emma Richardson
+ * @since 6.2.0
+ */
+@CompileStatic
+class LocalDateTimeConverter implements ValueConverter {
+    @Override
+    boolean canConvert(Object value) {
+        return value instanceof String || value instanceof LocalDateTime
+    }
+
+    @Override
+    Object convert(Object value) {
+        if (value instanceof LocalDateTime) {
+            return value
+        } else if (value instanceof CharSequence) {
+            String dateStr = value.toString()
+            if (!dateStr) {
+                return null
+            } else {
+                LocalDateTime.parse((String) value)
+            }
+        }
+    }
+
+    @Override
+    Class<?> getTargetType() {
+        return LocalDateTime
+    }
+}

grails-databinding/src/test/groovy/grails/databinding/SimpleDataBinderSpec.groovy

@@ -18,12 +18,14 @@ import grails.databinding.converters.ValueConverter
 import grails.databinding.errors.BindingError
 import grails.databinding.events.DataBindingListenerAdapter
 import org.grails.databinding.converters.DateConversionHelper
-
+import org.grails.databinding.converters.LocalDateTimeConverter
 import spock.lang.Ignore
 import spock.lang.Issue
 import spock.lang.Specification
 
 import java.text.SimpleDateFormat
+import java.time.LocalDateTime
+import java.time.format.DateTimeFormatter
 
 class SimpleDataBinderSpec extends Specification {
 
@@ -131,15 +133,24 @@ class SimpleDataBinderSpec extends Specification {
         def obj = new DateContainer()
         def nowUtilDate = new Date()
         def nowSqlDate = new java.sql.Date(nowUtilDate.time)
+        def localDateTime = "2013-04-15T21:26:31.973"
         def nowCalendar = Calendar.instance
 
         when:
-        binder.bind(obj, new SimpleMapDataBindingSource([utilDate: nowUtilDate, sqlDate: nowSqlDate, calendar: nowCalendar]))
+        binder.bind(obj, new SimpleMapDataBindingSource([utilDate: nowUtilDate, sqlDate: nowSqlDate, calendar: nowCalendar, localDateTime: localDateTime]))
 
         then:
         obj.utilDate == nowUtilDate
         obj.sqlDate == nowSqlDate
         obj.calendar == nowCalendar
+        obj.localDateTime == null
+
+        when:
+        binder.registerConverter(new LocalDateTimeConverter())
+        binder.bind(obj, new SimpleMapDataBindingSource([localDateTime: "2013-04-15T21:26:31.974"]))
+
+        then:
+        obj.localDateTime == LocalDateTime.parse("2013-04-15T21:26:31.974", DateTimeFormatter.ISO_LOCAL_DATE_TIME)
     }
 
     @Issue('GRAILS-10925')
@@ -711,6 +722,7 @@ class Fidget {
 }
 
 class DateContainer {
+    LocalDateTime localDateTime
     Date utilDate
     java.sql.Date sqlDate
     Calendar calendar

grails-plugin-databinding/src/main/groovy/org/grails/databinding/converters/DefaultConvertersConfiguration.java

@@ -195,6 +195,11 @@ protected DateConversionHelper defaultDateConverter() {
         return converter;
     }
 
+    @Bean("defaultLocalDateTimeConverter")
+    protected LocalDateTimeConverter defaultLocalDateTimeConverter() {
+        return new LocalDateTimeConverter();
+    }
+
     @Bean("timeZoneConverter")
     protected TimeZoneConverter defaultTimeZoneConverter() {
         return new TimeZoneConverter();