com.github.edgarespina.handlebars.Context Maven / Gradle / Ivy

Go to download
package com.github.edgarespina.handlebars;

import java.util.Map;

/**
 * Mustache/Handlabars are contextual template engines. This class represent the
 * 'context stack' of a template.
 * 
 * Objects and hashes should be pushed onto the context stack.
 * 
All elements on the context stack should be accessible.
 * 
Multiple sections per template should be permitted.
 * 
Failed context lookups should be considered falsey.
 * 
Dotted names should be valid for Section tags.
 * 
Dotted names that cannot be resolved should be considered falsey.
 * 
Dotted Names - Context Precedence: Dotted names should be resolved
 * against former resolutions.
 * 
 *
 * @author edgar.espina
 * @since 0.1.0
 */
public interface Context {

  /**
   * Resolved as '.' or 'this' inside templates.
   *
   * @return The model or data.
   */
  Object model();

  /**
   * A contextual storage useful for saving values in a thread-safety way. The
   * storage is cleaned up once a template has been rendered.
   *
   * @return A contextual storage. Never null.
   */
  Map storage();

  /**
   * Lookup the given key inside the context stack.
   * 
   * Objects and hashes should be pushed onto the context stack.
   * 
All elements on the context stack should be accessible.
   * 
Multiple sections per template should be permitted.
   * 
Failed context lookups should be considered falsey.
   * 
Dotted names should be valid for Section tags.
   * 
Dotted names that cannot be resolved should be considered falsey.
   * 
Dotted Names - Context Precedence: Dotted names should be resolved
   * against former resolutions.
   * 
   *
   * @param key The object key.
   * @return The value associated to the given key or null if no
   *         value is found.
   */
  Object get(final Object key);
}