org.springframework.web.servlet.tags.MessageTag Maven / Gradle / Ivy
/*
* Copyright 2002-2004 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;
import java.io.IOException;
import java.util.Collection;
import javax.servlet.jsp.JspException;
import javax.servlet.jsp.JspTagException;
import org.springframework.context.MessageSource;
import org.springframework.context.NoSuchMessageException;
import org.springframework.util.StringUtils;
import org.springframework.web.util.ExpressionEvaluationUtils;
import org.springframework.web.util.HtmlUtils;
import org.springframework.web.util.JavaScriptUtils;
import org.springframework.web.util.TagUtils;
/**
* Custom JSP tag to look up a message in the scope of this page.
* Messages are looked up using the ApplicationContext, and thus should
* support internationalization.
*
* Regards a HTML escaping setting, either on this tag instance,
* the page level, or the web.xml level. Can also apply JavaScript escaping.
*
*
If "code" isn't set or cannot be resolved, "text" will be used as default
* message. Thus, this tag can also be used for HTML escaping of any texts.
*
* @author Rod Johnson
* @author Juergen Hoeller
* @see #setCode
* @see #setText
* @see #setHtmlEscape
* @see #setJavaScriptEscape
* @see HtmlEscapeTag#setDefaultHtmlEscape
* @see org.springframework.web.util.WebUtils#HTML_ESCAPE_CONTEXT_PARAM
*/
public class MessageTag extends HtmlEscapingAwareTag {
private String code;
private Object arguments;
private String text;
private String var;
private String scope = TagUtils.SCOPE_PAGE;
private boolean javaScriptEscape = false;
/**
* Set the message code for this tag.
*/
public void setCode(String code) {
this.code = code;
}
/**
* Set optional message arguments for this tag, as a comma-delimited
* String (each String argument can contain JSP EL), an Object array
* (used as argument array), or a single Object (used as single argument).
*/
public void setArguments(Object arguments) {
this.arguments = arguments;
}
/**
* Set the message text for this tag.
*/
public void setText(String text) {
this.text = text;
}
/**
* Set PageContext attribute name under which to expose
* a variable that contains the resolved message.
* @see #setScope
* @see javax.servlet.jsp.PageContext#setAttribute
*/
public void setVar(String var) {
this.var = var;
}
/**
* Set the scope to export the variable to.
* Default is SCOPE_PAGE ("page").
* @see #setVar
* @see org.springframework.web.util.TagUtils#SCOPE_PAGE
* @see javax.servlet.jsp.PageContext#setAttribute
*/
public void setScope(String scope) {
this.scope = scope;
}
/**
* Set JavaScript escaping for this tag, as boolean value.
* Default is false.
*/
public void setJavaScriptEscape(String javaScriptEscape) throws JspException {
this.javaScriptEscape =
ExpressionEvaluationUtils.evaluateBoolean("javaScriptEscape", javaScriptEscape, pageContext);
}
protected final int doStartTagInternal() throws JspException, IOException {
MessageSource messageSource = getMessageSource();
if (messageSource == null) {
throw new JspTagException("No corresponding MessageSource found");
}
String resolvedCode = ExpressionEvaluationUtils.evaluateString("code", this.code, pageContext);
String resolvedText = ExpressionEvaluationUtils.evaluateString("text", this.text, pageContext);
String resolvedVar = ExpressionEvaluationUtils.evaluateString("var", this.var, pageContext);
try {
String msg = null;
if (resolvedCode != null) {
Object[] argumentsArray = null;
if (this.arguments instanceof String) {
argumentsArray = StringUtils.commaDelimitedListToStringArray((String) this.arguments);
for (int i = 0; i < argumentsArray.length; i++) {
argumentsArray[i] =
ExpressionEvaluationUtils.evaluateString(
"argument[" + i + "]", (String) argumentsArray[i], pageContext);
}
}
else if (this.arguments instanceof Object[]) {
argumentsArray = (Object[]) this.arguments;
}
else if (this.arguments instanceof Collection) {
argumentsArray = ((Collection) this.arguments).toArray();
}
else if (this.arguments != null) {
// assume a single argument object
argumentsArray = new Object[] {this.arguments};
}
if (resolvedText != null) {
msg = messageSource.getMessage(
resolvedCode, argumentsArray, resolvedText, getRequestContext().getLocale());
}
else {
msg = messageSource.getMessage(
resolvedCode, argumentsArray, getRequestContext().getLocale());
}
}
else {
msg = resolvedText;
}
// HTML and/or JavaScript escape, if demanded
msg = isHtmlEscape() ? HtmlUtils.htmlEscape(msg) : msg;
msg = this.javaScriptEscape ? JavaScriptUtils.javaScriptEscape(msg) : msg;
// expose as variable, if demanded
if (resolvedVar != null) {
String resolvedScope = ExpressionEvaluationUtils.evaluateString("scope", this.scope, pageContext);
pageContext.setAttribute(resolvedVar, msg, TagUtils.getScope(resolvedScope));
}
else {
writeMessage(msg);
}
return EVAL_BODY_INCLUDE;
}
catch (NoSuchMessageException ex) {
throw new JspTagException(getNoSuchMessageExceptionDescription(ex));
}
}
/**
* Write the message to the page.
*
Can be overridden in subclasses, e.g. for testing purposes.
* @param msg the message to write
* @throws IOException if writing failed
*/
protected void writeMessage(String msg) throws IOException {
pageContext.getOut().write(String.valueOf(msg));
}
/**
* Use the application context itself for default message resolution.
*/
protected MessageSource getMessageSource() {
return getRequestContext().getWebApplicationContext();
}
/**
* Return default exception message.
*/
protected String getNoSuchMessageExceptionDescription(NoSuchMessageException ex) {
return ex.getMessage();
}
}