SPR-8755 Add Button tag.

org.springframework.web.servlet/src/main/java/org/springframework/web/servlet/tags/form/ButtonTag.java

@@ -0,0 +1,147 @@
+/*
+ * Copyright 2002-2011 the original author or authors.
+ *
+ * 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 org.springframework.web.servlet.tags.form;
+
+import javax.servlet.jsp.JspException;
+
+import org.springframework.web.servlet.support.RequestDataValueProcessor;
+
+/**
+ * An HTML button tag. This tag is provided for completeness if the application 
+ * relies on a {@link RequestDataValueProcessor}.
+ *
+ * @author Rossen Stoyanchev
+ * @since 3.1
+ */
+@SuppressWarnings("serial")
+public class ButtonTag extends AbstractHtmlElementTag {
+
+	/**
+	 * The name of the '<code>disabled</code>' attribute.
+	 */
+	public static final String DISABLED_ATTRIBUTE = "disabled";
+
+	private TagWriter tagWriter;
+
+	private String name;
+	
+	private String value;
+
+	private String disabled;
+
+	/**
+	 * Set the value of the '<code>name</code>' attribute.
+	 */
+	public String getName() {
+		return name;
+	}
+
+	/**
+	 * Get the value of the '<code>name</code>' attribute.
+	 */
+	public void setName(String name) {
+		this.name = name;
+	}
+
+	/**
+	 * Get the value of the '<code>value</code>' attribute.
+	 */
+	public String getValue() {
+		return this.value;
+	}
+	
+	/**
+	 * Set the value of the '<code>value</code>' attribute.
+	 */
+	public void setValue(String value) {
+		this.value = value;
+	}
+	
+	/**
+	 * Get the value of the '<code>disabled</code>' attribute.
+	 */
+	public String getDisabled() {
+		return this.disabled;
+	}
+	
+	/**
+	 * Set the value of the '<code>disabled</code>' attribute.
+	 * May be a runtime expression.
+	 */
+	public void setDisabled(String disabled) {
+		this.disabled = disabled;
+	}
+
+	@Override
+	protected int writeTagContent(TagWriter tagWriter) throws JspException {
+		tagWriter.startTag("button");
+		writeDefaultAttributes(tagWriter);
+		tagWriter.writeAttribute("type", getType());
+		writeValue(tagWriter);
+		if (isDisabled()) {
+			tagWriter.writeAttribute(DISABLED_ATTRIBUTE, "disabled");
+		}
+		tagWriter.forceBlock();
+		this.tagWriter = tagWriter;
+		return EVAL_BODY_INCLUDE;
+	}
+
+	/**
+	 * Is the current HTML tag disabled?
+	 */
+	protected boolean isDisabled() throws JspException {
+		return evaluateBoolean(DISABLED_ATTRIBUTE, getDisabled());
+	}
+
+	/**
+	 * Writes the '<code>value</code>' attribute to the supplied {@link TagWriter}.
+	 * Subclasses may choose to override this implementation to control exactly
+	 * when the value is written.
+	 */
+	protected void writeValue(TagWriter tagWriter) throws JspException {
+		String valueToUse = (getValue() != null) ? getValue() : getDefaultValue();
+		tagWriter.writeAttribute("value", processFieldValue(getName(), valueToUse, getType()));
+	}
+
+    /**
+     * Return the default value.
+     *
+     * @return The default value if none supplied.
+     */
+    protected String getDefaultValue() {
+        return "Submit";
+    }
+
+	/**
+	 * Get the value of the '<code>type</code>' attribute. Subclasses
+	 * can override this to change the type of '<code>input</code>' element
+	 * rendered. Default value is '<code>submit</code>'.
+	 */
+	protected String getType() {
+		return "submit";
+	}
+
+	/**
+	 * Closes the '<code>button</code>' block tag.
+	 */
+	@Override
+	public int doEndTag() throws JspException {
+		this.tagWriter.endTag();
+		return EVAL_PAGE;
+	}
+
+}