Generating Documentation

To make usable class libraries to share with others, effective class library documentation is essential. For Ejscript programs, the ejsmod program can generate HTML documentation for class libraries similar to the Java, Javadoc tools. The ejsmod tool extracts the documentation from comments in the script code and from the script variable, function and type declarations. It automatically documents all non-private elements and creates a complete HTML web site for the documentation.

The Ejscript Language Library documentation has been prepared using the ejsmod tool.

Preparing Your Source

The first step in generating documentation is to add comments to your source code. These comments are called ejsdoc comments and are valid Ejscript comments that begin with the characters /**. For example:

/**
 *  Users full name including first and last name.
 */
var userName

By default, ejsmod will generate documentation for all elements regardless of whether they have an ejsdoc comment, but the description for elements without an ejsdoc comment will be empty.

Ejsdoc Comments

Ejsdoc comments will be parsed by ejsmod to extract information for the commented element, starting with the first sentence.

First Sentence

The first sentence is special. It is the brief, one line description used in indices and overviews. You don't need any special "@brief" or other tag like other documentation tools. Ejsmod uses a set of conventions to make documenting your code easier and the first of these conventions is to extract the first sentence as a brief description.

Remaining Sentences

The remaining sentences in the ejsdoc comment are captured as the full description for the element. The first sentence is removed and stored as the brief description, but will be restored in some locations where relevant to the documentation.

AT Directives

Embedded in the ejsdoc comment may be a set of directives that begin with the @ character. These typically are either one liners or continue until the next @directive or the end of the ejsdoc comment.

Directive Format Description
@param @param name Description Describe a parameter. The description continues up to the next @directive or the end of the ejsdoc comment. Multiple @param directives are permitted.
@return @return Description Describe the return value. If the sentence starts with a lower case word, then ejsmod will append the word "Returns" to the start of the description. You can also use (or misuse) the directive as @returns. Only a single @return directive is permitted.
@throw @throw TypeError Description Describe an exception that may be thrown by the function. The TypeError should be the name of an Error class. The description continues up to the next @directive or the end of the ejsdoc comment. Multiple @param directives are permitted.
@example @example Multi-line example Describe an example that illustrates use of the API. The description continues up to the next @directive or the end of the ejsdoc comment. Multiple @example directives are permitted.
@spec @spec name, [, name ...] Describe the standards conformance of the element. Typical values include ejs-NN for Ejscript conformant or ecma-3 for ECMAScript 3 compliance.
@see @see name [, name ...] Create a "See Also" link to another element in the documentation. Names should be comma separated. Multiple @see directives are permitted.

Here is an example comment specification from the Ejscript Language Library

/**
 *  Search for an item using strict equality "===". This call 
 *  searches from the start of the array for the specified element.
 *  @param element The object to search for.
 *  @param startIndex Where in the array (zero based) to start 
 *         searching for the object.
 *  @return The items index into the array if found, otherwise -1.
 *  @throws OutOfBoundsError If the starting index is greater 
 *          than or equal to the size of the array or less then 0.
 *  @spec ecma-3
 */
function indexOf(element: Object, 
    startIndex: Number = 0): Number
{
}

Embedded HTML

The ejsdoc comment may contain embedded HTML which will be passed through to the documentation without modification. In this manner, you can add your own styling. For example:

/** Some <b>bold</b> text */

Styling

Ejsmod generates a style sheet for use with the documentation. You are welcome to modify the contents of this style sheet, but it will be generated each time. Ejsmod is not yet capable of being "skinned" or "styled" to suite individual needs. This is planned for a future release.

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