/*
* Copyright 2014 Attila Szegedi, Daniel Dekany, Jonathan Revusky
*
* 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 freemarker.template;
import java.io.PrintWriter;
import java.io.StringWriter;
import java.io.Writer;
import freemarker.core.Configurable;
import freemarker.core.Environment;
import freemarker.core.StopException;
import freemarker.template.utility.StringUtil;
/**
* Used for the {@code template_exception_handler} configuration setting;
* see {@link Configurable#setTemplateExceptionHandler(TemplateExceptionHandler)} for more.
*/
public interface TemplateExceptionHandler {
/**
* Method called after a {@link TemplateException} was raised inside a template. The error is logged before this is
* called, so there's no need to log it here. The exception should be re-thrown unless you want to
* suppress the exception.
*
* <p>Note that you can check with {@link Environment#isInAttemptBlock()} if you are inside a {@code #attempt}
* block, which then will handle handle this exception and roll back the output generated inside it.
*
* <p>Note that {@link StopException}-s (raised by {@code #stop}) won't be captured.
*
* @param te The exception that occurred; don't forget to re-throw it unless you want to suppress it
* @param env The runtime environment of the template
* @param out This is where the output of the template is written
*/
void handleTemplateException(TemplateException te, Environment env, Writer out) throws TemplateException;
/**
* {@link TemplateExceptionHandler} that simply skips the failing instructions, letting the template continue
* executing. It does nothing to handle the event. Note that the exception is still logged, as with all
* other {@link TemplateExceptionHandler}-s.
*/
TemplateExceptionHandler IGNORE_HANDLER = new TemplateExceptionHandler() {
public void handleTemplateException(TemplateException te, Environment env, Writer out) {
// Do nothing
}
};
/**
* {@link TemplateExceptionHandler} that simply re-throws the exception; this should be used in most production
* systems.
*/
TemplateExceptionHandler RETHROW_HANDLER = new TemplateExceptionHandler() {
public void handleTemplateException(TemplateException te, Environment env, Writer out)
throws TemplateException {
throw te;
}
};
/**
* {@link TemplateExceptionHandler} useful when you developing non-HTML templates. This handler
* outputs the stack trace information to the client and then re-throws the exception.
*/
TemplateExceptionHandler DEBUG_HANDLER = new TemplateExceptionHandler() {
public void handleTemplateException(TemplateException te, Environment env, Writer out)
throws TemplateException {
if (!env.isInAttemptBlock()) {
PrintWriter pw = (out instanceof PrintWriter) ? (PrintWriter) out : new PrintWriter(out);
pw.print("FreeMarker template error (DEBUG mode; use RETHROW in production!):\n");
te.printStackTrace(pw, false, true, true);
pw.flush(); // To commit the HTTP response
}
throw te;
}
};
/**
* {@link TemplateExceptionHandler} useful when you developing HTML templates. This handler
* outputs the stack trace information to the client, formatting it so that it will be usually well readable
* in the browser, and then re-throws the exception.
*/
TemplateExceptionHandler HTML_DEBUG_HANDLER = new TemplateExceptionHandler() {
public void handleTemplateException(TemplateException te, Environment env, Writer out)
throws TemplateException {
if (!env.isInAttemptBlock()) {
boolean externalPw = out instanceof PrintWriter;
PrintWriter pw = externalPw ? (PrintWriter) out : new PrintWriter(out);
try {
pw.print("<!-- FREEMARKER ERROR MESSAGE STARTS HERE -->"
+ "<!-- ]]> -->"
+ "<script language=javascript>//\"></script>"
+ "<script language=javascript>//'></script>"
+ "<script language=javascript>//\"></script>"
+ "<script language=javascript>//'></script>"
+ "</title></xmp></script></noscript></style></object>"
+ "</head></pre></table>"
+ "</form></table></table></table></a></u></i></b>"
+ "<div align='left' "
+ "style='background-color:#FFFF7C; "
+ "display:block; border-top:double; padding:4px; margin:0; "
+ "font-family:Arial,sans-serif; ");
pw.print(FONT_RESET_CSS);
pw.print("'>"
+ "<b style='font-size:12px; font-style:normal; font-weight:bold; "
+ "text-decoration:none; text-transform: none;'>FreeMarker template error "
+ " (HTML_DEBUG mode; use RETHROW in production!)</b>"
+ "<pre style='display:block; background: none; border: 0; margin:0; padding: 0;"
+ "font-family:monospace; ");
pw.print(FONT_RESET_CSS);
pw.println("; white-space: pre-wrap; white-space: -moz-pre-wrap; white-space: -pre-wrap; "
+ "white-space: -o-pre-wrap; word-wrap: break-word;'>");
StringWriter stackTraceSW = new StringWriter();
PrintWriter stackPW = new PrintWriter(stackTraceSW);
te.printStackTrace(stackPW, false, true, true);
stackPW.close();
pw.println();
pw.println(StringUtil.XMLEncNQG(stackTraceSW.toString()));
pw.println("</pre></div></html>");
pw.flush(); // To commit the HTTP response
} finally {
if (!externalPw) pw.close();
}
} // if (!env.isInAttemptBlock())
throw te;
}
private static final String FONT_RESET_CSS =
"color:#A80000; font-size:12px; font-style:normal; font-variant:normal; "
+ "font-weight:normal; text-decoration:none; text-transform: none";
};
}