Fetching contributors…
Cannot retrieve contributors at this time
134 lines (107 sloc) 7.95 KB
layout title

JTransc uses Minitemplates in several places.

Minitemplates is an embedded simple template engine created for JTransc based on twig, my project atpl.js, liquid among others.

Use cases:

  • When embedding external code in anotations
  • When including target language files
  • When specifying a custom command line for building
  • When defining a target custom bootstrap main
  • When generating project files requiring for build tools

What can I do with Minitemplates?

Inside Minitemplates you have access to parameters/configuration variables for that build. Also you can get actual target generated names for: classes, methods and fields. Generated names could not match ones from the original source in some targets. Also minimizing/obfuscating names could lead to totally different names.


Minitemplates allow you to use tags and expressions.

Basic syntax: {% highlight django %}{% raw %} {% tag ... %} - A self-closed tag {% tag ... %}...{% end %} - A tag that opens and then ends (and can contain other meaningful tags inside) {{ expression }} - A expression that evaluates {% endraw %}{% endhighlight %}


Expressions are like other's language expressions. In there you can use normal unary and binary operators, access fields/elements with . or [] just like in ecmascript based languages. And there is an addition called filters. Filters are in postfix positions and are similar to extension methods, and are denoted with pipe | symbol. So for example the upper filter could be used like this {{ "mystring"|upper }}. You can have literals: strings, numbers and arrays. Also you can reference variables available in its current context. Inside the for tag you can access the iteration variable.

Available Standard Tags:

{% raw %}
{% if expression %}...{% end %}                 - Just evaluates fragment inside tag in the case expression evaluates as truthful
{% if expression %}...{% else %}...{% end %}    - Evaluates if or else blocks depending on the expression result
{% for var in expression %}...{% end %}         - Loops over an iterable expression and holds each value in the specified var
{% assign var = expression %}                   - Assigns the result of an expression to a variable
{% debug expression %}                          - Outputs debug information
{% endraw %}

Tags to statically reference classes, fields and methods

{% raw %}
{% SINIT %}                   - Replaces with a complete statement with a static initializer for a class. You must call this before calling or accessing static methods and fields.
{% CONSTRUCTOR %}  - Replaces with a class instantiation code for a specific constructor, requires appending brackets later.
{% CLASS %}                   - Replaces with the fully qualified name of the class.
{% METHOD %}  - Replaces with the method name.
{% FIELD %}   - Replaces with the field name.
{% IMETHOD %}  - Replaces with '.' plus the method name (in the case of javascript can be replaced with 'name' too).
{% IFIELD %}   - Replaces with '.' plus the field name (in the case of javascript can be replaced with 'name' too).
{% SMETHOD %} - It is a shortcut for CLASS + METHOD tags for calling static methods.
{% SFIELD %}  - It is a shortcut for CLASS + FIELD tags for accessing static fields.
{% endraw %}

Note: On METHOD and SMETHOD descriptor is optional when there is just one single method overloading. Otherwise a method descriptor looks like: (II)Ljava/lang/String; and you can find more about Method Descriptors in the java specification.

An example using this for Haxe generated code could be:

{% raw %}
static public function init() {
    {% SINIT %}

private function mouseInfo() return {% SFIELD %};

override public function onMouseUp(window:Window, x:Float, y:Float, button:Int):Void {
	mouseInfo(){% IMETHOD$MouseInfo:setScreenXY %}(,;
	mouseInfo(){% IFIELD$MouseInfo:buttons %} &= ~(1 << button);
	inputImpl(){% IMETHOD$Handler:onMouseUp %}(mouseInfo());
{% endraw %}

Available filters

{% raw %}
|length              - Evaluates to the length of a list or string
|upper               - Uppercases the whole string
|lower               - Lowercases the whole string
|capitalize          - Uppercases the first character of the string and lowercases the rest
|trim                - Strips starting and ending whitespace characters
|join('separator')   - Joins something iterable with the specified separator
|file_exists('file') - Evaluates to true in the case the specified file exists
|quote               - Quotes a string "like \"this\""
|escape              - Escapes a string (like quotes but without wrapping within "") like \"this\"
{% endraw %}

Available identifiers in templates

  • srcFolder- Operating system full path where target sources (haxe for example) are generated. Example: target/jtransc-haxe/src
  • buildFolder - Operating system full path with the jtransc target folder. Example: target/jtransc-haxe
  • haxeExtraFlags - A List<Pair<String, String>> with flags FLAG=VALUE. Example: listOf("-lib" to "haxe-ws:0.0.6")
  • haxeExtraDefines - A List with additional defines. Example: listOf("analyzer=1")
  • actualSubtarget - An object representing the actual subtarget (that object contains name, alias)
  • outputFile - Absolute Path to the expected output file Example: target/program.js
  • release - Boolean indicating wether this is a release build or not. Example: true
  • debug - Boolean indicating wether this is a debug build or not. Example: false
  • releasetype - String indicating kind of release. Possible values: "release" or "debug". Example: debug
  • settings - A AstBuildSettings object with the whole settings
  • title - Specified title in maven configuration
  • name - Specified name in maven configuration
  • package - Specified package in maven configuration
  • version - Specified version in maven configuration
  • company - Specified company in maven configuration
  • initialWidth - Specified initialWidth in maven configuration
  • initialHeight - Specified initialHeightin maven configuration
  • orientation - Specified orientation maven configuration. Possible values: (auto, portrait, landscape)
  • tempAssetsDir - (Deprecated use mergedAssetsdir)
  • mergedAssetsDir - Path to the temporal directory that contains all the assets merged together
  • embedResources - Boolean indicating wether to embed resources or not
  • assets - Folder containing assets
  • hasIcon - Boolean indicating if there was specified an icon or not
  • icon - Path to icon file
  • libraries - List of target libraries to include
  • extra - Map<String, String> containing all the extra defined configurations
  • JTRANSC_VERSION - Version of JTransc eg. 0.6.0

After building sources, inside for example HaxeCustomMain:

  • entryPointFile - File that holds the entrypoint
  • entryPointClass - Fully qualified name for the entry point class

Specific targets can define custom template variables. To prevent them being outdated, please locate CommonGenerator.params field and find references: