TemplateEngines

Overview

Module

• package: org.eclipse.dirigible.sdk.template
• source: template/TemplateEngines.java

Renders a template against a JSON parameter document. Three engines are available:

• Mustache — logic-less; perfect for emails and HTML fragments.
• Velocity — Apache Velocity with the platform's default tool set.
• JavaScript — evaluates ${expr} fragments through GraalJS for the full power of script expressions inside the template.

generate(template, parametersJson) picks the default engine (Mustache); the named variants are for explicit choice. The five-argument generate overload lets you change the marker pair (the Mustache defaults are double curly braces) — useful when the template body itself contains the delimiter characters.

Key Features:

• Three engines — pick the one that suits the template style.
• Custom markers — override start / end delimiters per call.
• JSON parameter document — consistent JSON shape across the platform.

Example Usage:

import org.eclipse.dirigible.sdk.template.TemplateEngines;

String out = TemplateEngines.generate(
    "Hello, {{name}}!",
    "{\"name\":\"Alice\"}");

String html = TemplateEngines.generateMustache(
    "<p>Order {{orderId}} total {{amount}}</p>",
    "{\"orderId\":\"42\",\"amount\":\"1299.00\"}");

Methods

generate()

Renders a template using the default (Mustache) engine.

public static String generate(String template, String parametersJson) throws IOException;

Parameter	Type	Description
template	String	Template body.
parametersJson	String	JSON document supplying the substitution values.

Returns

• Type: String
• Description: Rendered output.

generateMustache()

Renders explicitly with the Mustache engine.

public static String generateMustache(String template, String parametersJson) throws IOException;

generateVelocity()

Renders with Apache Velocity.

public static String generateVelocity(String template, String parametersJson) throws IOException;

generateJavascript()

Renders with the JavaScript engine — ${expr} fragments are evaluated through GraalJS.

public static String generateJavascript(String template, String parametersJson) throws IOException;

generate() — custom markers

Renders with custom delimiter markers (defaults vary per engine).

public static String generate(String location, String template, String parametersJson,
    String startMarker, String endMarker) throws IOException;

Parameter	Type	Description
location	String	Optional source label used in error messages.
template	String	Template body.
parametersJson	String	JSON document with substitution values.
startMarker	String	Opening delimiter (e.g. <%).
endMarker	String	Closing delimiter (e.g. %>).