Merge branch 'feature/create-and-modify-date-as-field-behaviors' into dev

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/tables/InsertAction.java

@@ -23,7 +23,6 @@ package com.kingsrook.qqq.backend.core.actions.tables;
 
 
 import java.io.Serializable;
-import java.time.Instant;
 import java.util.ArrayList;
 import java.util.HashMap;
 import java.util.HashSet;
@@ -207,17 +206,6 @@ public class InsertAction extends AbstractQActionFunction<InsertInput, InsertOut
          return (rs);
       }
 
-      /////////////////////////////////////////////
-      // set values in create date & modify date //
-      // todo .. better (not hard-coded names)   //
-      /////////////////////////////////////////////
-      Instant now = Instant.now();
-      for(QRecord record : insertInput.getRecords())
-      {
-         setValueIfTableHasField(record, insertInput.getTable(), "createDate", now);
-         setValueIfTableHasField(record, insertInput.getTable(), "modifyDate", now);
-      }
-
       //////////////////////////////////////////////////////
       // load the backend module and its insert interface //
       //////////////////////////////////////////////////////
@@ -233,29 +221,6 @@ public class InsertAction extends AbstractQActionFunction<InsertInput, InsertOut
 
 
 
-   /*******************************************************************************
-    ** If the table has a field with the given name, then set the given value in the
-    ** given record.
-    *******************************************************************************/
-   private static void setValueIfTableHasField(QRecord record, QTableMetaData table, String fieldName, Serializable value)
-   {
-      try
-      {
-         if(table.getFields().containsKey(fieldName))
-         {
-            record.setValue(fieldName, value);
-         }
-      }
-      catch(Exception e)
-      {
-         /////////////////////////////////////////////////
-         // this means field doesn't exist, so, ignore. //
-         /////////////////////////////////////////////////
-      }
-   }
-
-
-
    /*******************************************************************************
     **
     *******************************************************************************/
@@ -277,7 +242,7 @@ public class InsertAction extends AbstractQActionFunction<InsertInput, InsertOut
 
       setDefaultValuesInRecords(table, insertInput.getRecords());
 
-      ValueBehaviorApplier.applyFieldBehaviors(insertInput.getInstance(), table, insertInput.getRecords());
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, insertInput.getInstance(), table, insertInput.getRecords());
 
       runPreInsertCustomizerIfItIsTime(insertInput, preInsertCustomizer, AbstractPreInsertCustomizer.WhenToRun.BEFORE_UNIQUE_KEY_CHECKS);
       setErrorsIfUniqueKeyErrors(insertInput, table);

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/tables/UpdateAction.java

@@ -235,7 +235,7 @@ public class UpdateAction
       /////////////////////////////
       // run standard validators //
       /////////////////////////////
-      ValueBehaviorApplier.applyFieldBehaviors(updateInput.getInstance(), table, updateInput.getRecords());
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.UPDATE, updateInput.getInstance(), table, updateInput.getRecords());
       validatePrimaryKeysAreGiven(updateInput);
 
       if(oldRecordList.isPresent())

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/tables/helpers/UpdateActionRecordSplitHelper.java

@@ -22,7 +22,6 @@
 package com.kingsrook.qqq.backend.core.actions.tables.helpers;
 
 
-import java.io.Serializable;
 import java.time.Instant;
 import java.util.ArrayList;
 import java.util.List;
@@ -61,11 +60,6 @@ public class UpdateActionRecordSplitHelper
 
       for(QRecord record : updateInput.getRecords())
       {
-         ////////////////////////////////////////////
-         // todo .. better (not a hard-coded name) //
-         ////////////////////////////////////////////
-         setValueIfTableHasField(record, table, "modifyDate", now);
-
          List<String> updatableFields = table.getFields().values().stream()
             .map(QFieldMetaData::getName)
             // todo - intent here is to avoid non-updateable fields - but this
@@ -147,29 +141,6 @@ public class UpdateActionRecordSplitHelper
 
 
 
-   /*******************************************************************************
-    ** If the table has a field with the given name, then set the given value in the
-    ** given record.
-    *******************************************************************************/
-   protected void setValueIfTableHasField(QRecord record, QTableMetaData table, String fieldName, Serializable value)
-   {
-      try
-      {
-         if(table.getFields().containsKey(fieldName))
-         {
-            record.setValue(fieldName, value);
-         }
-      }
-      catch(Exception e)
-      {
-         /////////////////////////////////////////////////
-         // this means field doesn't exist, so, ignore. //
-         /////////////////////////////////////////////////
-      }
-   }
-
-
-
    /*******************************************************************************
     ** Getter for haveAnyWithoutErrors
     **

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/actions/values/ValueBehaviorApplier.java

@@ -25,12 +25,10 @@ package com.kingsrook.qqq.backend.core.actions.values;
 import java.util.List;
 import com.kingsrook.qqq.backend.core.model.data.QRecord;
 import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
-import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldType;
-import com.kingsrook.qqq.backend.core.model.metadata.fields.ValueTooLongBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
-import com.kingsrook.qqq.backend.core.model.statusmessages.BadInputStatusMessage;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
-import com.kingsrook.qqq.backend.core.utils.StringUtils;
 
 
 /*******************************************************************************
@@ -42,16 +40,10 @@ public class ValueBehaviorApplier
    /*******************************************************************************
     **
     *******************************************************************************/
-   public static void applyFieldBehaviors(QInstance instance, QTableMetaData table, List<QRecord> recordList)
+   public enum Action
    {
-      for(QFieldMetaData field : table.getFields().values())
+      INSERT,
-      {
+      UPDATE
-         String fieldName = field.getName();
-         if(field.getType().equals(QFieldType.STRING) && field.getMaxLength() != null)
-         {
-            applyValueTooLongBehavior(instance, recordList, field, fieldName);
-         }
-      }
    }
 
 
@@ -59,31 +51,18 @@ public class ValueBehaviorApplier
    /*******************************************************************************
     **
     *******************************************************************************/
-   private static void applyValueTooLongBehavior(QInstance instance, List<QRecord> recordList, QFieldMetaData field, String fieldName)
+   public static void applyFieldBehaviors(Action action, QInstance instance, QTableMetaData table, List<QRecord> recordList)
    {
-      ValueTooLongBehavior valueTooLongBehavior = field.getBehavior(instance, ValueTooLongBehavior.class);
+      if(CollectionUtils.nullSafeIsEmpty(recordList))
-
-      ////////////////////////////////////////////////////////////////////////////////////////////////////
-      // don't process PASS_THROUGH - so we don't have to iterate over the whole record list to do noop //
-      ////////////////////////////////////////////////////////////////////////////////////////////////////
-      if(valueTooLongBehavior != null && !valueTooLongBehavior.equals(ValueTooLongBehavior.PASS_THROUGH))
       {
-         for(QRecord record : recordList)
+         return;
+      }
+
+      for(QFieldMetaData field : table.getFields().values())
+      {
+         for(FieldBehavior<?> fieldBehavior : CollectionUtils.nonNullCollection(field.getBehaviors()))
          {
-            String value = record.getValueString(fieldName);
+            fieldBehavior.apply(action, recordList, instance, table, field);
-            if(value != null && value.length() > field.getMaxLength())
-            {
-               switch(valueTooLongBehavior)
-               {
-                  case TRUNCATE -> record.setValue(fieldName, StringUtils.safeTruncate(value, field.getMaxLength()));
-                  case TRUNCATE_ELLIPSIS -> record.setValue(fieldName, StringUtils.safeTruncate(value, field.getMaxLength(), "..."));
-                  case ERROR -> record.addError(new BadInputStatusMessage("The value for " + field.getLabel() + " is too long (max allowed length=" + field.getMaxLength() + ")"));
-                  case PASS_THROUGH ->
-                  {
-                  }
-                  default -> throw new IllegalStateException("Unexpected valueTooLongBehavior: " + valueTooLongBehavior);
-               }
-            }
          }
       }
    }

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/instances/QInstanceEnricher.java

@@ -42,6 +42,7 @@ import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
 import com.kingsrook.qqq.backend.core.model.metadata.code.QCodeReference;
 import com.kingsrook.qqq.backend.core.model.metadata.dashboard.QWidgetMetaDataInterface;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.AdornmentType;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.DynamicDefaultValueBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldAdornment;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldType;
@@ -94,10 +95,8 @@ public class QInstanceEnricher
 
    private JoinGraph joinGraph;
 
-   //////////////////////////////////////////////////////////
+   private boolean configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels        = true;
-   // todo - come up w/ a way for app devs to set configs! //
+   private boolean configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate = true;
-   //////////////////////////////////////////////////////////
-   private boolean configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels = true;
 
    //////////////////////////////////////////////////////////////////////////////////////////////////
    // let an instance define mappings to be applied during name-to-label enrichments,              //
@@ -464,6 +463,22 @@ public class QInstanceEnricher
             }
          }
       }
+
+      /////////////////////////////////////////////////////////////////////////
+      // add field behaviors for create date & modify date, if so configured //
+      /////////////////////////////////////////////////////////////////////////
+      if(configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate)
+      {
+         if("createDate".equals(field.getName()) && field.getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class) == null)
+         {
+            field.withBehavior(DynamicDefaultValueBehavior.CREATE_DATE);
+         }
+
+         if("modifyDate".equals(field.getName()) && field.getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class) == null)
+         {
+            field.withBehavior(DynamicDefaultValueBehavior.MODIFY_DATE);
+         }
+      }
    }
 
 
@@ -1220,4 +1235,66 @@ public class QInstanceEnricher
       labelMappings.clear();
    }
 
+
+
+   /*******************************************************************************
+    ** Getter for configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels
+    *******************************************************************************/
+   public boolean getConfigRemoveIdFromNameWhenCreatingPossibleValueFieldLabels()
+   {
+      return (this.configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels);
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels
+    *******************************************************************************/
+   public void setConfigRemoveIdFromNameWhenCreatingPossibleValueFieldLabels(boolean configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels)
+   {
+      this.configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels = configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels
+    *******************************************************************************/
+   public QInstanceEnricher withConfigRemoveIdFromNameWhenCreatingPossibleValueFieldLabels(boolean configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels)
+   {
+      this.configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels = configRemoveIdFromNameWhenCreatingPossibleValueFieldLabels;
+      return (this);
+   }
+
+
+
+   /*******************************************************************************
+    ** Getter for configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate
+    *******************************************************************************/
+   public boolean getConfigAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate()
+   {
+      return (this.configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate);
+   }
+
+
+
+   /*******************************************************************************
+    ** Setter for configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate
+    *******************************************************************************/
+   public void setConfigAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate(boolean configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate)
+   {
+      this.configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate = configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate;
+   }
+
+
+
+   /*******************************************************************************
+    ** Fluent setter for configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate
+    *******************************************************************************/
+   public QInstanceEnricher withConfigAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate(boolean configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate)
+   {
+      this.configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate = configAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate;
+      return (this);
+   }
+
 }

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/instances/QInstanceValidator.java

@@ -692,7 +692,7 @@ public class QInstanceValidator
 
       String prefix = "Field " + fieldName + " in table " + tableName + " ";
 
-      ValueTooLongBehavior behavior = field.getBehavior(qInstance, ValueTooLongBehavior.class);
+      ValueTooLongBehavior behavior = field.getBehaviorOrDefault(qInstance, ValueTooLongBehavior.class);
       if(behavior != null && !behavior.equals(ValueTooLongBehavior.PASS_THROUGH))
       {
          assertCondition(field.getMaxLength() != null, prefix + "specifies a ValueTooLongBehavior, but not a maxLength.");

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/DynamicDefaultValueBehavior.java

@@ -0,0 +1,164 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2022.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.metadata.fields;
+
+
+import java.io.Serializable;
+import java.time.Instant;
+import java.time.LocalDate;
+import java.util.List;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.logging.QLogger;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
+import static com.kingsrook.qqq.backend.core.logging.LogUtils.logPair;
+
+
+/*******************************************************************************
+ ** Field behavior that sets a default value for a field dynamically.
+ ** e.g., create-date fields get set to 'now' on insert.
+ ** e.g., modify-date fields get set to 'now' on insert and on update.
+ *******************************************************************************/
+public enum DynamicDefaultValueBehavior implements FieldBehavior<DynamicDefaultValueBehavior>
+{
+   CREATE_DATE,
+   MODIFY_DATE,
+   NONE;
+
+   private static final QLogger LOG = QLogger.getLogger(ValueTooLongBehavior.class);
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public DynamicDefaultValueBehavior getDefault()
+   {
+      return (NONE);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public void apply(ValueBehaviorApplier.Action action, List<QRecord> recordList, QInstance instance, QTableMetaData table, QFieldMetaData field)
+   {
+      if(this.equals(NONE))
+      {
+         return;
+      }
+
+      switch(this)
+      {
+         case CREATE_DATE -> applyCreateDate(action, recordList, table, field);
+         case MODIFY_DATE -> applyModifyDate(action, recordList, table, field);
+         default -> throw new IllegalStateException("Unexpected enum value: " + this);
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private void applyCreateDate(ValueBehaviorApplier.Action action, List<QRecord> recordList, QTableMetaData table, QFieldMetaData field)
+   {
+      if(!ValueBehaviorApplier.Action.INSERT.equals(action))
+      {
+         return;
+      }
+
+      setCreateDateOrModifyDateOnList(recordList, table, field);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private void applyModifyDate(ValueBehaviorApplier.Action action, List<QRecord> recordList, QTableMetaData table, QFieldMetaData field)
+   {
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      // check both of these (even though they're the only 2 values at the time of this writing), just in case more enum values are added in the future //
+      ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
+      if(!ValueBehaviorApplier.Action.INSERT.equals(action) && !ValueBehaviorApplier.Action.UPDATE.equals(action))
+      {
+         return;
+      }
+
+      setCreateDateOrModifyDateOnList(recordList, table, field);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private void setCreateDateOrModifyDateOnList(List<QRecord> recordList, QTableMetaData table, QFieldMetaData field)
+   {
+      String       fieldName = field.getName();
+      Serializable value     = getNow(table, field);
+
+      for(QRecord record : CollectionUtils.nonNullList(recordList))
+      {
+         record.setValue(fieldName, value);
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private Serializable getNow(QTableMetaData table, QFieldMetaData field)
+   {
+      if(QFieldType.DATE_TIME.equals(field.getType()))
+      {
+         return (Instant.now());
+      }
+      else if(QFieldType.DATE.equals(field.getType()))
+      {
+         return (LocalDate.now());
+      }
+      else
+      {
+         LOG.debug("Request to apply a " + this.name() + " DynamicDefaultValueBehavior to a non-date or date-time field", logPair("table", table.getName()), logPair("field", field.getName()));
+         return (null);
+      }
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   private void noop()
+   {
+
+   }
+
+}

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/FieldBehavior.java

@@ -22,10 +22,41 @@
 package com.kingsrook.qqq.backend.core.model.metadata.fields;
 
 
+import java.util.List;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+
+
 /*******************************************************************************
+ ** Interface for (expected to be?) enums which define behaviors that get applied
+ ** to fields.
+ **
+ ** At the present, these behaviors get applied before a field is stored (insert
+ ** or update), through the ValueBehaviorApplier class.
  **
  *******************************************************************************/
-public interface FieldBehavior
+public interface FieldBehavior<T extends FieldBehavior<T>>
 {
 
+   /*******************************************************************************
+    ** In case a behavior of this type wasn't set on the field, what should the
+    ** default of this type be?
+    *******************************************************************************/
+   T getDefault();
+
+   /*******************************************************************************
+    ** Apply this behavior to a list of records
+    *******************************************************************************/
+   void apply(ValueBehaviorApplier.Action action, List<QRecord> recordList, QInstance instance, QTableMetaData table, QFieldMetaData field);
+
+   /*******************************************************************************
+    ** control if multiple behaviors of this type should be allowed together on a field.
+    *******************************************************************************/
+   default boolean allowMultipleBehaviorsOfThisType()
+   {
+      return (false);
+   }
+
 }

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/QFieldMetaData.java

@@ -35,6 +35,7 @@ import com.fasterxml.jackson.annotation.JsonIgnore;
 import com.github.hervian.reflection.Fun;
 import com.kingsrook.qqq.backend.core.exceptions.QException;
 import com.kingsrook.qqq.backend.core.instances.QInstanceHelpContentManager;
+import com.kingsrook.qqq.backend.core.logging.QLogger;
 import com.kingsrook.qqq.backend.core.model.actions.tables.query.QQueryFilter;
 import com.kingsrook.qqq.backend.core.model.data.QField;
 import com.kingsrook.qqq.backend.core.model.data.QRecordEntity;
@@ -44,6 +45,7 @@ import com.kingsrook.qqq.backend.core.model.metadata.help.QHelpContent;
 import com.kingsrook.qqq.backend.core.model.metadata.security.FieldSecurityLock;
 import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
 import com.kingsrook.qqq.backend.core.utils.StringUtils;
+import static com.kingsrook.qqq.backend.core.logging.LogUtils.logPair;
 
 
 /*******************************************************************************
@@ -52,6 +54,8 @@ import com.kingsrook.qqq.backend.core.utils.StringUtils;
  *******************************************************************************/
 public class QFieldMetaData implements Cloneable
 {
+   private static final QLogger LOG = QLogger.getLogger(QFieldMetaData.class);
+
    private String     name;
    private String     label;
    private String     backendName;
@@ -73,8 +77,8 @@ public class QFieldMetaData implements Cloneable
    private String       possibleValueSourceName;
    private QQueryFilter possibleValueSourceFilter;
 
-   private Integer            maxLength;
+   private Integer               maxLength;
-   private Set<FieldBehavior> behaviors;
+   private Set<FieldBehavior<?>> behaviors;
 
    ////////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
    // w/ longer-term vision for FieldBehaviors                                                                           //
@@ -674,7 +678,7 @@ public class QFieldMetaData implements Cloneable
     ** Getter for behaviors
     **
     *******************************************************************************/
-   public Set<FieldBehavior> getBehaviors()
+   public Set<FieldBehavior<?>> getBehaviors()
    {
       return behaviors;
    }
@@ -682,11 +686,12 @@ public class QFieldMetaData implements Cloneable
 
 
    /*******************************************************************************
-    **
+    ** Get the FieldBehavior object of a given behaviorType (class) - but - if one
+    ** isn't set, then use the default from that type.
     *******************************************************************************/
-   public <T extends FieldBehavior> T getBehavior(QInstance instance, Class<T> behaviorType)
+   public <T extends FieldBehavior<T>> T getBehaviorOrDefault(QInstance instance, Class<T> behaviorType)
    {
-      for(FieldBehavior fieldBehavior : CollectionUtils.nonNullCollection(behaviors))
+      for(FieldBehavior<?> fieldBehavior : CollectionUtils.nonNullCollection(behaviors))
       {
          if(behaviorType.isInstance(fieldBehavior))
          {
@@ -701,9 +706,33 @@ public class QFieldMetaData implements Cloneable
       ///////////////////////////////////////////
       // return default behavior for this type //
       ///////////////////////////////////////////
-      if(behaviorType.equals(ValueTooLongBehavior.class))
+      if(behaviorType.isEnum())
       {
-         return behaviorType.cast(ValueTooLongBehavior.getDefault());
+         return (behaviorType.getEnumConstants()[0].getDefault());
+      }
+
+      return (null);
+   }
+
+
+
+   /*******************************************************************************
+    ** Get the FieldBehavior object of a given behaviorType (class) - and if one
+    ** isn't set, then return null.
+    *******************************************************************************/
+   public <T extends FieldBehavior<T>> T getBehaviorOnlyIfSet(Class<T> behaviorType)
+   {
+      if(behaviors == null)
+      {
+         return (null);
+      }
+
+      for(FieldBehavior<?> fieldBehavior : CollectionUtils.nonNullCollection(behaviors))
+      {
+         if(behaviorType.isInstance(fieldBehavior))
+         {
+            return (behaviorType.cast(fieldBehavior));
+         }
       }
 
       return (null);
@@ -715,7 +744,7 @@ public class QFieldMetaData implements Cloneable
     ** Setter for behaviors
     **
     *******************************************************************************/
-   public void setBehaviors(Set<FieldBehavior> behaviors)
+   public void setBehaviors(Set<FieldBehavior<?>> behaviors)
    {
       this.behaviors = behaviors;
    }
@@ -726,7 +755,7 @@ public class QFieldMetaData implements Cloneable
     ** Fluent setter for behaviors
     **
     *******************************************************************************/
-   public QFieldMetaData withBehaviors(Set<FieldBehavior> behaviors)
+   public QFieldMetaData withBehaviors(Set<FieldBehavior<?>> behaviors)
    {
       this.behaviors = behaviors;
       return (this);
@@ -738,12 +767,30 @@ public class QFieldMetaData implements Cloneable
     ** Fluent setter for behaviors
     **
     *******************************************************************************/
-   public QFieldMetaData withBehavior(FieldBehavior behavior)
+   public QFieldMetaData withBehavior(FieldBehavior<?> behavior)
    {
+      if(behavior == null)
+      {
+         LOG.debug("Skipping request to add null behavior", logPair("fieldName", getName()));
+         return (this);
+      }
+
       if(behaviors == null)
       {
          behaviors = new HashSet<>();
       }
+
+      if(!behavior.allowMultipleBehaviorsOfThisType())
+      {
+         @SuppressWarnings("unchecked")
+         FieldBehavior<?> existingBehaviorOfThisType = getBehaviorOnlyIfSet(behavior.getClass());
+         if(existingBehaviorOfThisType != null)
+         {
+            LOG.debug("Replacing a field behavior", logPair("fieldName", getName()), logPair("oldBehavior", existingBehaviorOfThisType), logPair("newBehavior", behavior));
+            this.behaviors.remove(existingBehaviorOfThisType);
+         }
+      }
+
       this.behaviors.add(behavior);
       return (this);
    }

qqq-backend-core/src/main/java/com/kingsrook/qqq/backend/core/model/metadata/fields/ValueTooLongBehavior.java

@@ -22,23 +22,85 @@
 package com.kingsrook.qqq.backend.core.model.metadata.fields;
 
 
+import java.util.List;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.logging.QLogger;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+import com.kingsrook.qqq.backend.core.model.statusmessages.BadInputStatusMessage;
+import com.kingsrook.qqq.backend.core.utils.StringUtils;
+import static com.kingsrook.qqq.backend.core.logging.LogUtils.logPair;
+
+
 /*******************************************************************************
+ ** Behaviors for string fields, if their value is too long.
  **
+ ** Note:  This was the first implementation of a FieldBehavior, so its test
+ ** coverage is provided in ValueBehaviorApplierTest.
  *******************************************************************************/
-public enum ValueTooLongBehavior implements FieldBehavior
+public enum ValueTooLongBehavior implements FieldBehavior<ValueTooLongBehavior>
 {
    TRUNCATE,
    TRUNCATE_ELLIPSIS,
    ERROR,
    PASS_THROUGH;
 
+   private static final QLogger LOG = QLogger.getLogger(ValueTooLongBehavior.class);
+
 
 
    /*******************************************************************************
     **
     *******************************************************************************/
-   public static FieldBehavior getDefault()
+   @Override
+   public ValueTooLongBehavior getDefault()
    {
-      return PASS_THROUGH;
+      return (PASS_THROUGH);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Override
+   public void apply(ValueBehaviorApplier.Action action, List<QRecord> recordList, QInstance instance, QTableMetaData table, QFieldMetaData field)
+   {
+      if(this.equals(PASS_THROUGH))
+      {
+         return;
+      }
+
+      String fieldName = field.getName();
+      if(!QFieldType.STRING.equals(field.getType()))
+      {
+         LOG.debug("Request to apply a ValueTooLongBehavior to a non-string field", logPair("table", table.getName()), logPair("field", fieldName));
+         return;
+      }
+
+      if(field.getMaxLength() == null)
+      {
+         LOG.debug("Request to apply a ValueTooLongBehavior to string field without a maxLength", logPair("table", table.getName()), logPair("field", fieldName));
+         return;
+      }
+
+      for(QRecord record : recordList)
+      {
+         String value = record.getValueString(fieldName);
+         if(value != null && value.length() > field.getMaxLength())
+         {
+            switch(this)
+            {
+               case TRUNCATE -> record.setValue(fieldName, StringUtils.safeTruncate(value, field.getMaxLength()));
+               case TRUNCATE_ELLIPSIS -> record.setValue(fieldName, StringUtils.safeTruncate(value, field.getMaxLength(), "..."));
+               case ERROR -> record.addError(new BadInputStatusMessage("The value for " + field.getLabel() + " is too long (max allowed length=" + field.getMaxLength() + ")"));
+               ///////////////////////////////////
+               // PASS_THROUGH is handled above //
+               ///////////////////////////////////
+               default -> throw new IllegalStateException("Unexpected enum value: " + this);
+            }
+         }
+      }
    }
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/tables/helpers/UpdateActionRecordSplitHelperTest.java

@@ -38,7 +38,6 @@ import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
 import com.kingsrook.qqq.backend.core.model.statusmessages.SystemErrorStatusMessage;
 import com.kingsrook.qqq.backend.core.utils.ListingHash;
 import org.junit.jupiter.api.Test;
-import static org.assertj.core.api.Assertions.assertThat;
 import static org.junit.jupiter.api.Assertions.assertEquals;
 import static org.junit.jupiter.api.Assertions.assertFalse;
 import static org.junit.jupiter.api.Assertions.assertTrue;
@@ -64,6 +63,7 @@ class UpdateActionRecordSplitHelperTest extends BaseTest
          .withField(new QFieldMetaData("B", QFieldType.INTEGER))
          .withField(new QFieldMetaData("modifyDate", QFieldType.DATE_TIME)));
 
+      Instant now = Instant.now();
       UpdateInput updateInput = new UpdateInput(tableName)
          .withRecord(new QRecord().withValue("id", 1).withValue("A", 1))
          .withRecord(new QRecord().withValue("id", 2).withValue("A", 2))
@@ -71,6 +71,7 @@ class UpdateActionRecordSplitHelperTest extends BaseTest
          .withRecord(new QRecord().withValue("id", 4).withValue("B", 3))
          .withRecord(new QRecord().withValue("id", 5).withValue("B", 3))
          .withRecord(new QRecord().withValue("id", 6).withValue("A", 4).withValue("B", 5));
+      updateInput.getRecords().forEach(r -> r.setValue("modifyDate", now));
       UpdateActionRecordSplitHelper updateActionRecordSplitHelper = new UpdateActionRecordSplitHelper();
       updateActionRecordSplitHelper.init(updateInput);
       ListingHash<List<String>, QRecord> recordsByFieldBeingUpdated = updateActionRecordSplitHelper.getRecordsByFieldBeingUpdated();
@@ -78,12 +79,6 @@ class UpdateActionRecordSplitHelperTest extends BaseTest
       Function<Collection<QRecord>, Set<Integer>> extractIds = (records) ->
          records.stream().map(r -> r.getValueInteger("id")).collect(Collectors.toSet());
 
-      ////////////////////////////////////////
-      // validate that modify dates got set //
-      ////////////////////////////////////////
-      updateInput.getRecords().forEach(r ->
-         assertThat(r.getValue("modifyDate")).isInstanceOf(Instant.class));
-
       //////////////////////////////////////////////////////////////
       // validate the grouping of records by fields-being-updated //
       //////////////////////////////////////////////////////////////

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/actions/values/ValueBehaviorApplierTest.java

@@ -39,7 +39,9 @@ import static org.junit.jupiter.api.Assertions.fail;
 
 
 /*******************************************************************************
- ** Unit test for ValueBehaviorApplier
+ ** Unit test for ValueBehaviorApplier - and also providing coverage for
+ ** ValueTooLongBehavior (the first implementation, which was previously in the
+ ** class under test).
  *******************************************************************************/
 class ValueBehaviorApplierTest extends BaseTest
 {
@@ -61,7 +63,7 @@ class ValueBehaviorApplierTest extends BaseTest
          new QRecord().withValue("id", 2).withValue("firstName", "John").withValue("lastName", "Last name too long").withValue("email", "john@smith.com"),
          new QRecord().withValue("id", 3).withValue("firstName", "First name too long").withValue("lastName", "Smith").withValue("email", "john.smith@emaildomainwayytolongtofit.com")
       );
-      ValueBehaviorApplier.applyFieldBehaviors(qInstance, table, recordList);
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, qInstance, table, recordList);
 
       assertEquals("First name", getRecordById(recordList, 1).getValueString("firstName"));
       assertEquals("Last na...", getRecordById(recordList, 2).getValueString("lastName"));
@@ -93,7 +95,7 @@ class ValueBehaviorApplierTest extends BaseTest
          new QRecord().withValue("id", 1).withValue("firstName", "First name too long").withValue("lastName", null).withValue("email", "john@smith.com"),
          new QRecord().withValue("id", 2).withValue("firstName", "").withValue("lastName", "Last name too long").withValue("email", "john@smith.com")
       );
-      ValueBehaviorApplier.applyFieldBehaviors(qInstance, table, recordList);
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, qInstance, table, recordList);
 
       assertEquals("First name too long", getRecordById(recordList, 1).getValueString("firstName"));
       assertNull(getRecordById(recordList, 1).getValueString("lastName"));

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/instances/QInstanceEnricherTest.java

@@ -29,6 +29,7 @@ import java.util.Optional;
 import com.kingsrook.qqq.backend.core.BaseTest;
 import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.AdornmentType;
+import com.kingsrook.qqq.backend.core.model.metadata.fields.DynamicDefaultValueBehavior;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.FieldAdornment;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldMetaData;
 import com.kingsrook.qqq.backend.core.model.metadata.fields.QFieldType;
@@ -493,4 +494,39 @@ class QInstanceEnricherTest extends BaseTest
       return (tableMetaData);
    }
 
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testCreateDateAndModifyDateBehaviors()
+   {
+      QInstance qInstance = TestUtils.defineInstance();
+      qInstance.addTable(newTable("A", "id", "createDate", "modifyDate"));
+      QTableMetaData table = qInstance.getTable("A");
+
+      ////////////////////////////////////////////////
+      // make sure behavior wasn't there by default //
+      ////////////////////////////////////////////////
+      assertNull(table.getField("createDate").getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+      assertNull(table.getField("modifyDate").getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+
+      //////////////////////////////////////////////////////////////////
+      // make sure if config'ing off the adding of the behavior works //
+      //////////////////////////////////////////////////////////////////
+      new QInstanceEnricher(qInstance)
+         .withConfigAddDynamicDefaultValuesToFieldsNamedCreateDateAndModifyDate(false)
+         .enrich();
+      assertNull(table.getField("createDate").getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+      assertNull(table.getField("modifyDate").getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+
+      /////////////////////////////////////////////////////////////////////////////////////////////
+      // make sure default value for the config (e.g., in a new enricher) is to add the behavior //
+      /////////////////////////////////////////////////////////////////////////////////////////////
+      new QInstanceEnricher(qInstance).enrich();
+      assertEquals(DynamicDefaultValueBehavior.CREATE_DATE, table.getField("createDate").getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+      assertEquals(DynamicDefaultValueBehavior.MODIFY_DATE, table.getField("modifyDate").getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+   }
+
 }

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/model/metadata/fields/DynamicDefaultValueBehaviorTest.java

@@ -0,0 +1,139 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2024.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.metadata.fields;
+
+
+import java.time.LocalDate;
+import java.util.List;
+import com.kingsrook.qqq.backend.core.BaseTest;
+import com.kingsrook.qqq.backend.core.actions.values.ValueBehaviorApplier;
+import com.kingsrook.qqq.backend.core.context.QContext;
+import com.kingsrook.qqq.backend.core.model.data.QRecord;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.model.metadata.tables.QTableMetaData;
+import com.kingsrook.qqq.backend.core.utils.TestUtils;
+import org.junit.jupiter.api.Test;
+import static org.assertj.core.api.Assertions.assertThat;
+import static org.junit.jupiter.api.Assertions.assertNotNull;
+import static org.junit.jupiter.api.Assertions.assertNull;
+
+
+/*******************************************************************************
+ ** Unit test for DynamicDefaultValueBehavior 
+ *******************************************************************************/
+class DynamicDefaultValueBehaviorTest extends BaseTest
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testCreateDateHappyPath()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+
+      QRecord record = new QRecord().withValue("id", 1);
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, qInstance, table, List.of(record));
+
+      assertNotNull(record.getValue("createDate"));
+      assertNotNull(record.getValue("modifyDate"));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testModifyDateHappyPath()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+
+      QRecord record = new QRecord().withValue("id", 1);
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.UPDATE, qInstance, table, List.of(record));
+
+      assertNull(record.getValue("createDate"));
+      assertNotNull(record.getValue("modifyDate"));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testNone()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+      table.getField("createDate").withBehavior(DynamicDefaultValueBehavior.NONE);
+      table.getField("modifyDate").withBehavior(DynamicDefaultValueBehavior.NONE);
+
+      QRecord record = new QRecord().withValue("id", 1);
+
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, qInstance, table, List.of(record));
+      assertNull(record.getValue("createDate"));
+      assertNull(record.getValue("modifyDate"));
+
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.UPDATE, qInstance, table, List.of(record));
+      assertNull(record.getValue("createDate"));
+      assertNull(record.getValue("modifyDate"));
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testDateInsteadOfDateTimeField()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+      table.getField("createDate").withType(QFieldType.DATE);
+
+      QRecord record = new QRecord().withValue("id", 1);
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, qInstance, table, List.of(record));
+      assertNotNull(record.getValue("createDate"));
+      assertThat(record.getValue("createDate")).isInstanceOf(LocalDate.class);
+   }
+
+
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testNonDateField()
+   {
+      QInstance      qInstance = QContext.getQInstance();
+      QTableMetaData table     = qInstance.getTable(TestUtils.TABLE_NAME_PERSON_MEMORY);
+      table.getField("firstName").withBehavior(DynamicDefaultValueBehavior.CREATE_DATE);
+
+      QRecord record = new QRecord().withValue("id", 1);
+      ValueBehaviorApplier.applyFieldBehaviors(ValueBehaviorApplier.Action.INSERT, qInstance, table, List.of(record));
+      assertNull(record.getValue("firstName"));
+   }
+
+}

qqq-backend-core/src/test/java/com/kingsrook/qqq/backend/core/model/metadata/fields/QFieldMetaDataTest.java

@@ -0,0 +1,71 @@
+/*
+ * QQQ - Low-code Application Framework for Engineers.
+ * Copyright (C) 2021-2024.  Kingsrook, LLC
+ * 651 N Broad St Ste 205 # 6917 | Middletown DE 19709 | United States
+ * contact@kingsrook.com
+ * https://github.com/Kingsrook/
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Affero General Public License as
+ * published by the Free Software Foundation, either version 3 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Affero General Public License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.kingsrook.qqq.backend.core.model.metadata.fields;
+
+
+import com.kingsrook.qqq.backend.core.BaseTest;
+import com.kingsrook.qqq.backend.core.model.metadata.QInstance;
+import com.kingsrook.qqq.backend.core.utils.CollectionUtils;
+import org.junit.jupiter.api.Test;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+
+/*******************************************************************************
+ ** Unit test for QFieldMetaData 
+ *******************************************************************************/
+class QFieldMetaDataTest extends BaseTest
+{
+
+   /*******************************************************************************
+    **
+    *******************************************************************************/
+   @Test
+   void testFieldBehaviors()
+   {
+      /////////////////////////////////////////
+      // create field - assert default state //
+      /////////////////////////////////////////
+      QFieldMetaData field = new QFieldMetaData("createDate", QFieldType.DATE_TIME);
+      assertTrue(CollectionUtils.nullSafeIsEmpty(field.getBehaviors()));
+      assertNull(field.getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+      assertEquals(DynamicDefaultValueBehavior.NONE, field.getBehaviorOrDefault(new QInstance(), DynamicDefaultValueBehavior.class));
+
+      //////////////////////////////////////
+      // add NONE behavior - assert state //
+      //////////////////////////////////////
+      field.withBehavior(DynamicDefaultValueBehavior.NONE);
+      assertEquals(1, field.getBehaviors().size());
+      assertEquals(DynamicDefaultValueBehavior.NONE, field.getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+      assertEquals(DynamicDefaultValueBehavior.NONE, field.getBehaviorOrDefault(new QInstance(), DynamicDefaultValueBehavior.class));
+
+      /////////////////////////////////////////////////////////
+      // replace behavior - assert it got rid of the old one //
+      /////////////////////////////////////////////////////////
+      field.withBehavior(DynamicDefaultValueBehavior.CREATE_DATE);
+      assertEquals(1, field.getBehaviors().size());
+      assertEquals(DynamicDefaultValueBehavior.CREATE_DATE, field.getBehaviorOnlyIfSet(DynamicDefaultValueBehavior.class));
+      assertEquals(DynamicDefaultValueBehavior.CREATE_DATE, field.getBehaviorOrDefault(new QInstance(), DynamicDefaultValueBehavior.class));
+   }
+
+}