7.1.x Scaffolding Display Constraint Expansion

grails-datamapping-validation/src/main/groovy/grails/gorm/validation/Constrained.groovy

@@ -88,9 +88,16 @@ interface Constrained {
      */
     boolean isUrl()
     /**
-     * @return Whether the value should be displayed
+     * @return Whether the value should be displayed (for backwards compatibility)
+     * @deprecated Use {@link #getDisplayType()} instead for more granular control
      */
     boolean isDisplay()
+
+    /**
+     * @return The display type controlling where this property is shown in scaffolded views
+     * @since 7.1
+     */
+    DisplayType getDisplayType()
     /**
      * @return Whether the value is editable
      */

grails-datamapping-validation/src/main/groovy/grails/gorm/validation/DefaultConstrainedProperty.groovy

@@ -70,8 +70,8 @@ class DefaultConstrainedProperty implements ConstrainedProperty {
     protected final Map<String, Constraint> appliedConstraints = new LinkedHashMap<String, Constraint>()
 
     // simple constraints
-    /** whether the property should be displayed */
-    boolean display = true
+    /** the display type controlling where the property is shown in scaffolded views */
+    DisplayType displayType = null
     /**
      * whether the property is editable
      */
@@ -581,6 +581,52 @@ class DefaultConstrainedProperty implements ConstrainedProperty {
         }
     }
 
+    /**
+     * @return Whether the property should be displayed (for backwards compatibility).
+     *         Returns true unless displayType is explicitly set to NONE.
+     * @deprecated Use {@link #getDisplayType()} instead for more granular control
+     */
+    @Override
+    boolean isDisplay() {
+        displayType != DisplayType.NONE
+    }
+
+    /**
+     * Returns the display value for property access compatibility with ClassPropertyFetcher.
+     * Returns the displayType if set, otherwise returns the boolean display value.
+     * This method exists to ensure ClassPropertyFetcher.getPropertyDescriptor("display") works.
+     * @return The display value (DisplayType or Boolean)
+     */
+    Object getDisplay() {
+        displayType != null ? displayType : isDisplay()
+    }
+
+    /**
+     * Sets the display constraint with backwards compatibility for boolean values.
+     * @param value Can be a Boolean (true/false) or a DisplayType enum value
+     */
+    void setDisplay(Object value) {
+        if (value instanceof Boolean) {
+            this.displayType = value ? null : DisplayType.NONE
+        } else if (value instanceof DisplayType) {
+            this.displayType = value
+        } else if (value == null) {
+            this.displayType = null
+        } else {
+            throw new IllegalArgumentException("display constraint must be a Boolean or DisplayType, got: ${value?.class?.name}")
+        }
+    }
+
+    /**
+     * @return The display type controlling where this property is shown in scaffolded views.
+     *         Returns null if not explicitly set (default behavior applies).
+     * @since 7.1
+     */
+    @Override
+    DisplayType getDisplayType() {
+        this.displayType
+    }
+
     @SuppressWarnings('rawtypes')
     Map getAttributes() {
         return attributes

grails-datamapping-validation/src/main/groovy/grails/gorm/validation/DisplayType.groovy

@@ -0,0 +1,81 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you 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
+ *
+ *    https://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 grails.gorm.validation
+
+/**
+ * Enum representing the display behavior for a constrained property in scaffolded views.
+ *
+ * <p>This enum controls where a property is displayed in generated scaffolding views:</p>
+ * <ul>
+ *   <li>{@link #ALL} - Display everywhere, including overriding default blacklists (e.g., dateCreated, lastUpdated)</li>
+ *   <li>{@link #NONE} - Never display in any view</li>
+ *   <li>{@link #INPUT_ONLY} - Display only in input forms (create/edit views)</li>
+ *   <li>{@link #OUTPUT_ONLY} - Display only in output views (show/index views)</li>
+ * </ul>
+ *
+ * <p>Example usage in domain class constraints:</p>
+ * <pre>
+ * import static grails.gorm.validation.DisplayType.*
+ *
+ * class Book {
+ *     String title
+ *     Date dateCreated
+ *     String internalNotes
+ *
+ *     static constraints = {
+ *         dateCreated display: ALL      // Override blacklist, show everywhere
+ *         internalNotes display: NONE   // Never show
+ *     }
+ * }
+ * </pre>
+ *
+ * <p>For backwards compatibility, boolean values are also supported:</p>
+ * <ul>
+ *   <li>{@code display: true} is equivalent to the default behavior (not setting display)</li>
+ *   <li>{@code display: false} is equivalent to {@link #NONE}</li>
+ * </ul>
+ *
+ * @author Scott Murphy Heiberg
+ * @since 7.1
+ */
+enum DisplayType {
+
+    /**
+     * Display the property in all views (input and output).
+     * This also overrides the default blacklist for properties like dateCreated and lastUpdated.
+     */
+    ALL,
+
+    /**
+     * Never display the property in any view.
+     */
+    NONE,
+
+    /**
+     * Display the property only in input views (create and edit forms).
+     */
+    INPUT_ONLY,
+
+    /**
+     * Display the property only in output views (show and index/list views).
+     */
+    OUTPUT_ONLY
+
+}

grails-datamapping-validation/src/test/groovy/grails/gorm/validation/DisplayTypeSpec.groovy

@@ -0,0 +1,151 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one
+ *  or more contributor license agreements.  See the NOTICE file
+ *  distributed with this work for additional information
+ *  regarding copyright ownership.  The ASF licenses this file
+ *  to you 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
+ *
+ *    https://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 grails.gorm.validation
+
+import org.grails.datastore.gorm.validation.constraints.registry.DefaultConstraintRegistry
+import spock.lang.Specification
+
+class DisplayTypeSpec extends Specification {
+
+    DefaultConstrainedProperty constrainedProperty
+
+    void setup() {
+        constrainedProperty = new DefaultConstrainedProperty(
+            TestDomain,
+            "testProperty",
+            String,
+            new DefaultConstraintRegistry()
+        )
+    }
+
+    void "test default displayType is null"() {
+        expect:
+        constrainedProperty.displayType == null
+    }
+
+    void "test default isDisplay returns true"() {
+        expect:
+        constrainedProperty.display == true
+    }
+
+    void "test setDisplay with boolean false sets displayType to NONE"() {
+        when:
+        constrainedProperty.setDisplay(false)
+
+        then:
+        constrainedProperty.displayType == DisplayType.NONE
+        constrainedProperty.display == false
+    }
+
+    void "test setDisplay with boolean true sets displayType to null"() {
+        when:
+        constrainedProperty.setDisplay(true)
+
+        then:
+        constrainedProperty.displayType == null
+        constrainedProperty.display == true
+    }
+
+    void "test setDisplay with DisplayType.ALL"() {
+        when:
+        constrainedProperty.setDisplay(DisplayType.ALL)
+
+        then:
+        constrainedProperty.displayType == DisplayType.ALL
+        constrainedProperty.display == true
+    }
+
+    void "test setDisplay with DisplayType.NONE"() {
+        when:
+        constrainedProperty.setDisplay(DisplayType.NONE)
+
+        then:
+        constrainedProperty.displayType == DisplayType.NONE
+        constrainedProperty.display == false
+    }
+
+    void "test setDisplay with DisplayType.INPUT_ONLY"() {
+        when:
+        constrainedProperty.setDisplay(DisplayType.INPUT_ONLY)
+
+        then:
+        constrainedProperty.displayType == DisplayType.INPUT_ONLY
+        constrainedProperty.display == true  // isDisplay still returns true for INPUT_ONLY
+    }
+
+    void "test setDisplay with DisplayType.OUTPUT_ONLY"() {
+        when:
+        constrainedProperty.setDisplay(DisplayType.OUTPUT_ONLY)
+
+        then:
+        constrainedProperty.displayType == DisplayType.OUTPUT_ONLY
+        constrainedProperty.display == true  // isDisplay still returns true for OUTPUT_ONLY
+    }
+
+    void "test setDisplay with null resets to default"() {
+        given:
+        constrainedProperty.setDisplay(DisplayType.NONE)
+
+        when:
+        constrainedProperty.setDisplay(null)
+
+        then:
+        constrainedProperty.displayType == null
+        constrainedProperty.display == true
+    }
+
+    void "test setDisplay with invalid type throws exception"() {
+        when:
+        constrainedProperty.setDisplay("invalid")
+
+        then:
+        thrown(IllegalArgumentException)
+    }
+
+    void "test applyConstraint with display false sets displayType to NONE"() {
+        when:
+        constrainedProperty.applyConstraint("display", false)
+
+        then:
+        constrainedProperty.displayType == DisplayType.NONE
+        constrainedProperty.display == false
+    }
+
+    void "test applyConstraint with display true sets displayType to null"() {
+        when:
+        constrainedProperty.applyConstraint("display", true)
+
+        then:
+        constrainedProperty.displayType == null
+        constrainedProperty.display == true
+    }
+
+    void "test applyConstraint with DisplayType enum"() {
+        when:
+        constrainedProperty.applyConstraint("display", DisplayType.INPUT_ONLY)
+
+        then:
+        constrainedProperty.displayType == DisplayType.INPUT_ONLY
+        constrainedProperty.display == true
+    }
+
+    static class TestDomain {
+        String testProperty
+    }
+}

grails-doc/src/en/ref/Constraints.adoc

@@ -176,13 +176,62 @@ Some constraints have no impact on persistence but customize the scaffolding. It
 |===
 |Constraint|Description
 
-|display|Boolean that determines whether the property is displayed in the scaffolding views. If `true` (the default), the property _is_ displayed.
+|display|Controls whether and where the property is displayed in scaffolding views. Accepts a boolean or a `DisplayType` enum value (see below).
 |editable|Boolean that determines whether the property can be edited from the scaffolding views. If `false`, the associated form fields are displayed in read-only mode.
 |format|Specify a display format for types that accept one, such as dates. For example, 'yyyy-MM-dd'.
 |password|Boolean indicating whether this is property should be displayed with a password field. Only works on fields that would normally be displayed with a text field.
 |widget|Controls what widget is used to display the property. For example, 'textarea' will force the scaffolding to use a <textArea> tag.
 |===
 
+==== The display Constraint
+
+The `display` constraint controls whether a property appears in scaffolded views. It accepts either a boolean value or a `DisplayType` enum value for fine-grained control.
+
+===== Boolean Values (Backwards Compatible)
+
+[source,groovy]
+----
+static constraints = {
+    internalNotes display: false  // Never show this property
+    title display: true           // Show this property (default behavior)
+}
+----
+
+===== DisplayType Enum Values
+
+For more control over where properties are displayed, use the `DisplayType` enum:
+
+[source,groovy]
+----
+import static grails.gorm.validation.DisplayType.*
+
+class Book {
+    String title
+    String isbn
+    Date dateCreated
+    Date lastUpdated
+    String internalNotes
+
+    static constraints = {
+        dateCreated display: ALL         // Override blacklist, show in all views
+        lastUpdated display: OUTPUT_ONLY // Show only in show/index views
+        isbn display: INPUT_ONLY         // Show only in create/edit forms
+        internalNotes display: NONE      // Never show
+    }
+}
+----
+
+|===
+|DisplayType Value|Description
+
+|`ALL`|Display the property in all views (input and output). This also overrides the default blacklist for properties like `dateCreated` and `lastUpdated`.
+|`NONE`|Never display the property in any view. Equivalent to `display: false`.
+|`INPUT_ONLY`|Display the property only in input views (create and edit forms).
+|`OUTPUT_ONLY`|Display the property only in output views (show and index/list views).
+|===
+
+NOTE: Properties like `version`, `dateCreated`, and `lastUpdated` are excluded from input forms by default. Using `display: ALL` or `display: INPUT_ONLY` on these properties will override this blacklist and include them in input forms.
+
 
 === Programmatic access