freemarker.core.TemplateProcessingTracer Maven / Gradle / Ivy
Show all versions of freemarker-gae Show documentation
/*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.core;
import freemarker.template.Template;
/**
* Hooks to monitor as templates run. This may be used to implement profiling, coverage analysis, execution tracing,
* and other on-the-fly debugging mechanisms.
*
* Use {@link Environment#setTemplateProcessingTracer(TemplateProcessingTracer)} to set a tracer for the current
* environment.
*
* @since 2.3.33
*/
public interface TemplateProcessingTracer {
/**
* Invoked by {@link Environment} whenever it starts processing a new template element. A template element is a
* directive call, an interpolation (like ${...}), a comment block, or static text. Expressions
* are not template elements.
*/
void enterElement(Environment env, TracedElement tracedElement);
/**
* Invoked by {@link Environment} whenever it completes processing a new template element.
*
* @see #enterElement(Environment, TracedElement)
*/
void exitElement(Environment env, TracedElement tracedElement);
/**
* Information about the template element that we enter of exit; do NOT implement this (outside FreeMarker), as
* new methods can be added to this anytime!
*
* @since 2.3.33
*/
interface TracedElement {
/**
* The {@link Template} that contains this element.
*/
Template getTemplate();
/**
* 1-based index of the line (row) of the first character of the element in the template.
*/
int getBeginLine();
/**
* 1-based index of the column of the first character of the element in the template.
*/
int getBeginColumn();
/**
* 1-based index of the line (row) of the last character of the element in the template.
*/
int getEndColumn();
/**
* 1-based index of the column of the last character of the element in the template.
*/
int getEndLine();
/**
* If this is an element that has no nested elements.
*/
boolean isLeaf();
/**
* One-line description of the element, that also contains the parameter expressions, but not the nested content
* (child elements). There are no hard backward-compatibility guarantees regarding the format used, although
* it shouldn't change unless to fix a bug.
*/
String getDescription();
}
}