1 files changed, 115 insertions, 0 deletions
diff --git a/server/src/com/vaadin/ui/declarative/converters/DesignToStringConverter.java b/server/src/com/vaadin/ui/declarative/converters/DesignToStringConverter.java
new file mode 100644
index 0000000000..d80119bea1
--- /dev/null
+++ b/server/src/com/vaadin/ui/declarative/converters/DesignToStringConverter.java
@@ -0,0 +1,115 @@
+/*
+ * Copyright 2000-2014 Vaadin Ltd.
+ * 
+ * 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 com.vaadin.ui.declarative.converters;
+
+import java.lang.reflect.InvocationTargetException;
+import java.util.Locale;
+
+import com.vaadin.data.util.converter.Converter;
+import com.vaadin.ui.declarative.DesignAttributeHandler;
+
+/**
+ * Utility class for {@link DesignAttributeHandler} that deals with converting
+ * various types to string.
+ * 
+ * @since 7.4
+ * @author Vaadin Ltd
+ * @param <TYPE>
+ *            Type of the data being converted.
+ */
+public class DesignToStringConverter<TYPE> implements Converter<String, TYPE> {
+
+    private final Class<? extends TYPE> type;
+
+    private final String staticMethodName;
+
+    /**
+     * A string that corresponds to how a null value is stored.
+     */
+    public static final String NULL_VALUE_REPRESENTATION = "";
+
+    /**
+     * Constructs the converter for a given type. Implicitly requires that a
+     * static method {@code valueOf(String)} is present in the type to do the
+     * conversion.
+     * 
+     * @param type
+     *            Type of values to convert.
+     */
+    public DesignToStringConverter(Class<? extends TYPE> type) {
+        this(type, "valueOf");
+    }
+
+    /**
+     * Constructs the converter for a given type, giving the name of the public
+     * static method that does the conversion from String.
+     * 
+     * @param type
+     *            Type to convert.
+     * @param staticMethodName
+     *            Method to call when converting from String to this type. This
+     *            must be public and static method that returns an object of
+     *            passed type.
+     */
+    public DesignToStringConverter(Class<? extends TYPE> type, String staticMethodName) {
+        this.type = type;
+        this.staticMethodName = staticMethodName;
+    }
+
+    @Override
+    public TYPE convertToModel(String value, Class<? extends TYPE> targetType,
+            Locale locale) throws Converter.ConversionException {
+        try {
+            return type.cast(type
+                    .getMethod(this.staticMethodName, String.class).invoke(
+                            null, value));
+        } catch (IllegalAccessException e) {
+            throw new Converter.ConversionException(e);
+        } catch (IllegalArgumentException e) {
+            throw new Converter.ConversionException(e);
+        } catch (InvocationTargetException e) {
+            throw new Converter.ConversionException(e);
+        } catch (NoSuchMethodException e) {
+            throw new Converter.ConversionException(e);
+        } catch (SecurityException e) {
+            throw new Converter.ConversionException(e);
+        } catch (RuntimeException e) {
+            throw new Converter.ConversionException(e);
+        }
+    }
+
+    @Override
+    public String convertToPresentation(TYPE value,
+            Class<? extends String> targetType, Locale locale)
+            throws Converter.ConversionException {
+        if (value == null) {
+            return NULL_VALUE_REPRESENTATION;
+        } else {
+            return value.toString();
+        }
+    }
+
+    @Override
+    public Class<TYPE> getModelType() {
+        return (Class<TYPE>) this.type;
+    }
+
+    @Override
+    public Class<String> getPresentationType() {
+        return String.class;
+    }
+
+}