#105 fixed

superfields/src/main/java/org/vaadin/miki/superfields/dates/DatePatternHelper.java

@@ -1,5 +1,6 @@
 package org.vaadin.miki.superfields.dates;
 
+import com.vaadin.flow.component.AttachEvent;
 import com.vaadin.flow.component.Component;
 
 /**
@@ -9,7 +10,7 @@
  * @author miki
  * @since 2020-05-02
  */
-final class DatePatternHelper {
+final class DatePatternHelper<C extends Component & HasDatePattern> {
 
     /**
      * Returns the pattern descriptor string expected by the client-side code.
@@ -52,20 +53,48 @@ private static String convertDatePatternToClientPattern(DatePattern pattern) {
         }
     }
 
+    private final C source;
+
     /**
-     * Does magic and sets the display pattern on the client side.
-     * Requires the client-side connector to have a {@code setDisplayPattern} method.
-     * @param source Source component.
-     * @param pattern Pattern to set.
+     * Creates a helper for a given source object.
+     * The client-side representation should have mixed in methods from {@code date-pattern-mixin.js}.
+     * @param source Source to use.
+     */
+    DatePatternHelper(C source) {
+        this.source = source;
+        this.source.addAttachListener(this::onAttached);
+    }
+
+    /**
+     * Class client-side method {@code initPatternSetting()} that, well, inits pattern setting.
+     * In general, client-side code overrides a few methods to make sure pattern displaying and parsing works properly with custom patterns.
      */
-    static void setClientSidePattern(Component source, DatePattern pattern) {
-        source.getElement().getNode().runWhenAttached(ui -> ui.beforeClientResponse(source, context ->
-                source.getElement().callJsFunction("setDisplayPattern", source.getElement(), convertDatePatternToClientPattern(pattern))
+    protected void initPatternSetting() {
+        this.source.getElement().getNode().runWhenAttached(ui -> ui.beforeClientResponse(this.source, context ->
+                this.source.getElement().callJsFunction("initPatternSetting", this.source)
         ));
     }
 
-    private DatePatternHelper() {
-        // instances not allowed
+    /**
+     * Callback when onAttach() is called.
+     * @param event An {@link AttachEvent}.
+     */
+    protected void onAttached(AttachEvent event) {
+        this.initPatternSetting();
+        this.updateClientSidePattern();
+    }
+
+    /**
+     * Does magic and sets the display pattern on the client side.
+     * Requires the client-side connector to have a {@code setDisplayPattern} method.
+     */
+    protected void updateClientSidePattern() {
+        this.source.getElement().getNode().runWhenAttached(ui -> ui.beforeClientResponse(this.source, context ->
+                this.source.getElement().callJsFunction(
+                        "setDisplayPattern",
+                        this.source.getElement(), convertDatePatternToClientPattern(this.source.getDatePattern())
+                )
+        ));
     }
 
 }

superfields/src/main/java/org/vaadin/miki/superfields/dates/SuperDatePicker.java

@@ -30,6 +30,8 @@ public class SuperDatePicker extends DatePicker
                    WithValueMixin<AbstractField.ComponentValueChangeEvent<DatePicker, LocalDate>, LocalDate, SuperDatePicker>,
                    WithIdMixin<SuperDatePicker> {
 
+    private final DatePatternHelper<SuperDatePicker> delegate = new DatePatternHelper<>(this);
+
     private DatePattern datePattern;
 
     public SuperDatePicker() {
@@ -77,22 +79,25 @@ public SuperDatePicker(String label, LocalDate initialDate, ValueChangeListener<
     }
 
     public SuperDatePicker(LocalDate initialDate, Locale locale) {
-        super(initialDate, locale);
+        super(initialDate);
+        this.setLocale(locale);
     }
 
     @Override
     public final void setLocale(Locale locale) {
-        this.getElement().getNode().runWhenAttached(ui -> ui.beforeClientResponse(this, context ->
-                this.getElement().callJsFunction("initPatternSetting", this.getElement())
-        ));
-        SuperDatePickerI18nHelper.updateI18N(locale, this::getI18n, this::setI18n);
+        // there is a call for setting locale from the superclass' constructor
+        // and when that happens, the field is not yet initialised
+        if(this.delegate != null) {
+            this.delegate.initPatternSetting();
+            SuperDatePickerI18nHelper.updateI18N(locale, this::getI18n, this::setI18n);
+        }
         super.setLocale(locale);
     }
 
     @Override
     public void setDatePattern(DatePattern datePattern) {
         this.datePattern = datePattern;
-        DatePatternHelper.setClientSidePattern(this, datePattern);
+        this.delegate.updateClientSidePattern();
     }
 
     @Override

superfields/src/main/java/org/vaadin/miki/superfields/dates/SuperDateTimePicker.java

@@ -36,6 +36,8 @@ public class SuperDateTimePicker extends DateTimePicker
     private static final String INTERNAL_DATE_PICKER_FIELD_NAME = "datePicker";
     private static final String INTERNAL_TIME_PICKER_FIELD_NAME = "timePicker";
 
+    private final DatePatternHelper<SuperDateTimePicker> delegate = new DatePatternHelper<>(this);
+
     private DatePattern datePattern;
 
     public SuperDateTimePicker() {
@@ -89,19 +91,20 @@ public SuperDateTimePicker(LocalDateTime initialDateTime, Locale locale) {
 
     @Override
     public void setLocale(Locale locale) {
-            this.getElement().getNode().runWhenAttached(ui -> ui.beforeClientResponse(this, context ->
-                this.getElement().callJsFunction("initPatternSetting", this)
-            ))
-        ;
-        SuperDatePickerI18nHelper.updateI18N(locale, this::getDatePickerI18n, this::setDatePickerI18n);
+        // this method is called from the constructor of the superclass
+        // which means that first time it gets called, the delegate is not yet initialised
+        if(this.delegate != null) {
+            this.delegate.initPatternSetting();
+            SuperDatePickerI18nHelper.updateI18N(locale, this::getDatePickerI18n, this::setDatePickerI18n);
+        }
         super.setLocale(locale);
     }
 
     /**
      * Exposes an internal {@link DatePicker}, if it was successfully obtained through reflection.
      * @return A {@link DatePicker} used by this component, if possible.
      */
-    public Optional<DatePicker> getDatePicker() {
+    public Optional<DatePicker> getInternalDatePicker() {
         return ReflectTools.getValueOfField(this, DatePicker.class, INTERNAL_DATE_PICKER_FIELD_NAME);
     }
 
@@ -116,7 +119,7 @@ public Optional<TimePicker> getInternalTimePicker() {
     @Override
     public void setDatePattern(DatePattern pattern) {
         this.datePattern = pattern;
-        DatePatternHelper.setClientSidePattern(this, pattern);
+        this.delegate.updateClientSidePattern();
     }
 
     @Override