Template Engine

The template component of ModelAnt 2.25 is migrated as follows:

Usage

As of the convention above:

  • Construct a Template Engine with the unique name stated in the template compilation context:
engine = TemplateEngineFactory.constructEngine(templateCompilationContext)
  • Lookup the Template Engine after its instantiation, as many times as needed:
engine = TemplateEngineFactory.getEngine(uniqueName)
  • Use the Template Engine to render an object by naming a template
engine.render(targetFile, targetObject, templateName, bindings)
  • Use the Template Engine to render an object, inlined in the rendering of another object:
engine.render(targetObject, templateName, context)

The template is identified by the class name of the object to render and the template name (when provided explicitly) or the name of the calling method in engine.render(targetObject, context).

Template Syntax

The templates are stored in files with .jsp extension in order to reuse existing JSP editors with syntax highlight and additional support in JSP authoring.

  • The template consists of template elements, starting with optional imports and comments:
<template> ::= {<scriptlet import>|<scriptlet comment>}{<template element>}
  • The scriptlet import is a standard java import declaration, allowed in the Java language version of the underlying JRE:
<scriptlet import> ::= "<%@" <import> "%>"
<import> ::= standard java import declaration
  • The template element is either a static text, dynamic expression, scriptlet, or comment:
<template element> ::= <static text> | <expression> | <scriptlet> | <scriptlet comment>
  • The static text is strasferred to the output as it is. It should not contain <% substring
<static text> ::= string of any charaters, not containing <% substring
  • The expression provides the dynamic content in the text. These are standard JSP scriptlet expressions, translated to Java as expressions in the place they are used:
<expression> ::= "<%=" <java expression> "%>"
<java expression> ::= standard expression in Java
  • The scriptlet embeds java code to control the rendering of the nested template elements. These are standard JSP scriptlets:
<scriptlet> ::= "<%" <java statement> "%>"
<java statement> ::= <java fragment> {"%>" <template element> "<%" <java fragment>}
  • The scriptlet comments describe the template. They cannot be nested. Translated to Java as comments between /* and */:
<scriptlet comment> ::= "<%--" text "--%>"
  • Each template renders an instance of a specific java class. The qualified class name of the rendered class or interface is identified by the names of the nested directories, relative to the template root directory, by concatenating them, separated by dotc “.” (i.e. the dots replace the directories separators “/” or ""). For example:
    • java/lang/String/hello.jsp is a template rendering instances of java.lang.String
    • java/util/ArrayList/world.jsp is a template rendering instances of java.util.ArrayList

NOTE: The syntax of of the templates is changed (simplified), compared to the syntax in 2.25 version.

Project Directories

According to the ModelAnt conventions for Maven, the templates are located in /src/template project directory

Compilation Dependencies

Any use of the modelant Templates should use the following dependencies:

<dependencies>
  <dependency>
    <groupId>net.mdatools</groupId>
    <artifactId>modelant.template.api</artifactId>
    <version>${revision}</version>
  </dependency>
</dependencies>

Execution Dependencies

The use of modelant Templates can be integrated in modelant or independent of modelant. The following depedency is just enough to run:

<dependencies>
  <dependency>
    <groupId>net.mdatools</groupId>
    <artifactId>modelant.template.impl</artifactId>
    <version>${revision}</version>
  </dependency>
</dependencies>

Modules