org.springframework.web.servlet.tags.form.FormTag Maven / Gradle / Ivy
/*
* Copyright 2002-2007 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.ServletResponse;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.PageContext;
import org.springframework.util.ObjectUtils;
import org.springframework.util.StringUtils;
import org.springframework.web.util.HtmlUtils;
/**
* Data-binding aware JSP tag for rendering an HTML 'form' whose
* inner elements are bound to properties on a {@link #setCommandName command object}.
*
* Users should place the command object into the
* {@link org.springframework.web.servlet.ModelAndView} when populating the
* data for their view. The name of this command object can be configured
* using the {@link #setCommandName commandName} property.
*
*
The default value for the {@link #setCommandName commandName} property
* is 'command' which corresponds to the default name when using
* the {@link org.springframework.web.servlet.mvc.SimpleFormController}.
*
*
Inner tags can access the name of the command object via the
* {@link javax.servlet.jsp.PageContext}. The attribute name is defined in
* {@link #COMMAND_NAME_VARIABLE_NAME}.
*
* @author Rob Harrop
* @author Juergen Hoeller
* @since 2.0
* @see org.springframework.web.servlet.mvc.SimpleFormController
*/
public class FormTag extends AbstractHtmlElementTag {
/**
* The default HTTP method using which form values are sent to the server: "post".
*/
private static final String DEFAULT_METHOD = "post";
/**
* The default command object name: "command".
*/
public static final String DEFAULT_COMMAND_NAME = "command";
/**
* The name of the 'name' attribute.
*/
public static final String NAME_ATTRIBUTE = "name";
/**
* The name of the 'onsubmit' attribute.
*/
public static final String ONSUBMIT_ATTRIBUTE = "onsubmit";
/**
* The name of the 'onreset' attribute.
*/
public static final String ONRESET_ATTRIBUTE = "onreset";
/**
* The name of the 'method' attribute.
*/
public static final String METHOD_ATTRIBUTE = "method";
/**
* The name of the 'action' attribute.
*/
public static final String ACTION_ATTRIBUTE = "action";
/**
* The name of the 'enctype' attribute.
*/
public static final String ENCTYPE_ATTRIBUTE = "enctype";
/**
* The {@link TagWriter} instance used by this tag.
*/
private TagWriter tagWriter;
/**
* The name of the command object.
*/
private String commandName = DEFAULT_COMMAND_NAME;
/**
* The value of the 'name' attribute.
*/
private String name;
/**
* The value of the 'action' attribute.
*/
private String action;
/**
* The value of the 'method' attribute.
*/
private String method = DEFAULT_METHOD;
/**
* The value of the 'enctype' attribute.
*/
private String enctype;
/**
* The value of the 'onsubmit' attribute.
*/
private String onsubmit;
/**
* The value of the 'onreset' attribute.
*/
private String onreset;
/**
* Set the name of the command object.
*
May be a runtime expression.
*/
public void setCommandName(String commandName) {
this.commandName = commandName;
}
/**
* Get the value of the 'commandName' attribute.
* May be a runtime expression.
*/
protected String getCommandName() {
return this.commandName;
}
/**
* Set the value of the 'name' attribute.
* May be a runtime expression.
*/
public void setName(String name) {
this.name = name;
}
/**
* Set the value of the 'action' attribute.
* May be a runtime expression.
*/
public void setAction(String action) {
this.action = (action != null ? action : "");
}
/**
* Get the value of the 'action' attribute.
* May be a runtime expression.
*/
protected String getAction() {
return this.action;
}
/**
* Set the value of the 'method' attribute.
* May be a runtime expression.
*/
public void setMethod(String method) {
this.method = method;
}
/**
* Get the value of the 'method' attribute.
* May be a runtime expression.
*/
protected String getMethod() {
return this.method;
}
/**
* Set the value of the 'enctype' attribute.
* May be a runtime expression.
*/
public void setEnctype(String enctype) {
this.enctype = enctype;
}
/**
* Get the value of the 'enctype' attribute.
* May be a runtime expression.
*/
protected String getEnctype() {
return this.enctype;
}
/**
* Set the value of the 'onsubmit' attribute.
* May be a runtime expression.
*/
public void setOnsubmit(String onsubmit) {
this.onsubmit = onsubmit;
}
/**
* Get the value of the 'onsubmit' attribute.
* May be a runtime expression.
*/
protected String getOnsubmit() {
return this.onsubmit;
}
/**
* Set the value of the 'onreset' attribute.
* May be a runtime expression.
*/
public void setOnreset(String onreset) {
this.onreset = onreset;
}
/**
* Get the value of the 'onreset' attribute.
* May be a runtime expression.
*/
protected String getOnreset() {
return this.onreset;
}
/**
* Writes the opening part of the block 'form' tag and exposes
* the command name in the {@link javax.servlet.jsp.PageContext}.
* @param tagWriter the {@link TagWriter} to which the form content is to be written
* @return {@link javax.servlet.jsp.tagext.Tag#EVAL_BODY_INCLUDE}
*/
protected int writeTagContent(TagWriter tagWriter) throws JspException {
this.tagWriter = tagWriter;
this.tagWriter.startTag("form");
writeDefaultAttributes(tagWriter);
this.tagWriter.writeAttribute(METHOD_ATTRIBUTE, getDisplayString(evaluate(METHOD_ATTRIBUTE, getMethod())));
this.tagWriter.writeAttribute(ACTION_ATTRIBUTE, resolveAction());
writeOptionalAttribute(tagWriter, ENCTYPE_ATTRIBUTE, getEnctype());
writeOptionalAttribute(tagWriter, ONSUBMIT_ATTRIBUTE, getOnsubmit());
writeOptionalAttribute(tagWriter, ONRESET_ATTRIBUTE, getOnreset());
this.tagWriter.forceBlock();
// expose the command name for nested tags
this.pageContext.setAttribute(COMMAND_NAME_VARIABLE_NAME, resolveCommandName(), PageContext.REQUEST_SCOPE);
return EVAL_BODY_INCLUDE;
}
/**
* Name is not a valid attribute for form on XHTML 1.0. However,
* it is sometimes needed for backward compatibility.
*/
protected String getName() throws JspException {
return this.name;
}
/**
* Autogenerated IDs correspond to the command name.
*/
protected String autogenerateId() throws JspException {
return resolveCommandName();
}
/**
* {@link #evaluate Resolves} and returns the name of the command object.
* @throws IllegalArgumentException if the command object resolves to null
*/
protected String resolveCommandName() throws JspException {
Object resolvedCommmandName = evaluate(COMMAND_NAME_ATTRIBUTE, getCommandName());
if (resolvedCommmandName == null) {
throw new IllegalArgumentException("'commandName' must not be null");
}
return (String) resolvedCommmandName;
}
/**
* Resolve the value of the 'action' attribute.
*
If the user configured an 'action' value then
* the result of evaluating this value is used. Otherwise, the
* {@link org.springframework.web.servlet.support.RequestContext#getRequestUri() originating URI}
* is used.
* @return the value that is to be used for the 'action' attribute
*/
protected String resolveAction() throws JspException {
String action = getAction();
if (StringUtils.hasText(action)) {
return getDisplayString(evaluate(ACTION_ATTRIBUTE, action));
}
else {
String requestUri = getRequestContext().getRequestUri();
ServletResponse response = this.pageContext.getResponse();
if (response instanceof HttpServletResponse) {
requestUri = ((HttpServletResponse) response).encodeURL(requestUri);
String queryString = getRequestContext().getQueryString();
if (StringUtils.hasText(queryString)) {
requestUri += "?" + HtmlUtils.htmlEscapeQueryStringParameters(queryString);
}
}
if (StringUtils.hasText(requestUri)) {
return requestUri;
} else {
throw new IllegalArgumentException("Attribute 'action' is required. Attempted to resolve " +
"against current request URI but request URI was null.");
}
}
}
/**
* Closes the 'form' block tag and removes the command name
* from the {@link javax.servlet.jsp.PageContext}.
*/
public int doEndTag() throws JspException {
this.tagWriter.endTag();
this.pageContext.getRequest().removeAttribute(COMMAND_NAME_VARIABLE_NAME);
return EVAL_PAGE;
}
/**
* Clears the stored {@link TagWriter}.
*/
public void doFinally() {
super.doFinally();
this.tagWriter = null;
}
/**
* Override resolve CSS class since error class is not supported.
*/
protected String resolveCssClass() throws JspException {
return ObjectUtils.getDisplayString(evaluate("class", getCssClass()));
}
/**
* Unsupported for forms.
* @throws UnsupportedOperationException always
*/
public void setPath(String path) {
throw new UnsupportedOperationException("The 'path' attribute is not supported for forms.");
}
/**
* Unsupported for forms.
* @throws UnsupportedOperationException always
*/
public void setCssErrorClass(String cssErrorClass) {
throw new UnsupportedOperationException("The 'cssErrorClass' attribute is not supported for forms.");
}
}