Add Date API methods to FormField values

smack-extensions/src/main/java/org/jivesoftware/smackx/xdata/FormField.java

@@ -17,8 +17,10 @@
 
 package org.jivesoftware.smackx.xdata;
 
+import java.text.ParseException;
 import java.util.ArrayList;
 import java.util.Collections;
+import java.util.Date;
 import java.util.List;
 
 import org.jivesoftware.smack.packet.NamedElement;
@@ -27,6 +29,8 @@ import org.jivesoftware.smack.util.XmlStringBuilder;
 
 import org.jivesoftware.smackx.xdatavalidation.packet.ValidateElement;
 
+import org.jxmpp.util.XmppDateTime;
+
 /**
  * Represents a field of a form. The field could be used to represent a question to complete,
  * a completed question or a data returned from a search. The exact interpretation of the field
@@ -266,6 +270,21 @@ public class FormField implements NamedElement {
         return firstValue.toString();
     }
 
+    /**
+     * Parses the first value of this form field as XEP-0082 date/time format and returns a date instance or {@code null}.
+     *
+     * @return a Date instance representing the date/time information of the first value of this field.
+     * @throws ParseException if parsing fails.
+     * @since 4.3.0
+     */
+    public Date getFirstValueAsDate() throws ParseException {
+        String valueString = getFirstValue();
+        if (valueString == null) {
+            return null;
+        }
+        return XmppDateTime.parseXEP0082Date(valueString);
+    }
+
     /**
      * Returns the variable name that the question is filling out.
      * <p>
@@ -361,6 +380,18 @@ public class FormField implements NamedElement {
         }
     }
 
+    /**
+     * Adds the given Date as XEP-0082 formated string by invoking {@link #addValue(CharSequence)} after the date
+     * instance was formated.
+     *
+     * @param date the date instance to add as XEP-0082 formated string.
+     * @since 4.3.0
+     */
+    public void addValue(Date date) {
+        String dateString = XmppDateTime.formatXEP0082Date(date);
+        addValue(dateString);
+    }
+
     /**
      * Adds a default values to the question if the question is part of a form to fill out.
      * Otherwise, adds an answered values to the question.