dataflo.ws/index.js

Zero-code JSON config-based dataflow engine for Node, PhoneGap and browser.

var define;
if (typeof define === "undefined") {
	define = function (classInstance) {
		classInstance (require, exports, module);
	};
}

var registry = {};
define (function (require, exports, module) {

var MODULE_NAME = 'dataflo.ws';
var INITIATOR_PATH = 'initiator';

var path,
	fs,
	common = require ('./common'),
	color  = require ('./color');

if ($isServerSide) {
	path = require ('path');
	fs   = require ('fs');
}

color.error     = color.bind (color, "red+white_bg");
color.path      = color.cyan.bind (color);
color.dataflows = color.green.bind (color, "dataflows");


module.exports.common = common;
module.exports.color  = color;


var util   = require ('util');
try {
	util.clone = require('node-v8-clone').clone;
} catch (e) {
	console.log (color.dataflows(), color.path ('node-v8-clone'), 'recommended to install to fasten clone operations');
}


var instanceTypes = [ 'initiator', 'task' ];

// - - -

// TODO: add requirejs loading

function registryLookup (instanceType, instanceName) {
	var instanceClass = registry[instanceType] &&
		registry[instanceType][instanceName];

	if (!instanceClass) {
		if ($isClientSide) {
			console.error (
				'you need to run dataflows.register ("'
				+instanceType+'", "'+instanceName
				+'", instance) before using this task'
			);
			return;
		}


		var fixedName = instanceName;
		if (instanceType == 'initiator') {
			fixedName = instanceName.replace(/d$/, '');
			if (fixedName !== instanceName) {
				console.warn(
		'[DEPRECATED] Remove trailing "d" from "%s" in your initiator config',
					instanceName
				);
			}
		} else if (instanceType == 'task') {
			fixedName = instanceName.replace(/^(dataflo\.ws\/)?task\//, '');
			if (fixedName !== instanceName) {
				console.warn(
		'[DEPRECATED] Remove preceding "task/" from "%s" in your task config',
					instanceName
				);
			}
		}

		var project;
		var project_root;

		if (common.getProject)
			project = common.getProject();

		if (project)
			project_root = project.root;

		instanceClass = getModule (instanceType, fixedName, false, project_root);
	}

	return registry[instanceType][instanceName] = instanceClass;
};

function getModule (type, name, optional, root) {
	optional = optional || false;
	var mod;

	if (!root) {
		if (typeof project !== "undefined") {
			root = project.root;
		} else {
			root = path.dirname (require.main.filename);
		}
	}

	var paths = [
		path.join('dataflo.ws', type, name)
	];

	if (root) {
		paths.push (path.resolve(root.path ? root.path : root, type, name));
		paths.push (path.resolve(root.path ? root.path : root, 'node_modules', type, name));
	}

	paths.push (name);

	var taskFound = paths.some (function (modPath) {
		try {
			mod = require(modPath);
			return true;
		} catch (e) {
			// assuming format: Error: Cannot find module 'csv2array' {"code":"MODULE_NOT_FOUND"}
			if (e.toString().indexOf(name + '\'') > 0 && e.code == "MODULE_NOT_FOUND") {
				return false;
			} else {
				console.error (
					'requirement failed:',
					color.error (e.toString()),
					root
						? "in " + color.path (root.relative (modPath))
						: ""
				);
				return true;
			}
		}
	});

	if (!mod && !optional)
		console.error ("module " + type + " " + name + " cannot be used");

	return mod;

}

instanceTypes.forEach(function(instanceType) {
	registry[instanceType] = {};
	module.exports[instanceType] = function (instanceName) {
		return registryLookup (instanceType, instanceName);
	};
});

// - - -

/**
 * Makes symlinks from modules to base dataflo.ws directory.
 */
module.exports.install = function (moduleName) {
	var baseDir = path.dirname(require.resolve(MODULE_NAME));
	var nodePath = path.dirname(baseDir);
	var moduleDir = path.join(nodePath, moduleName);

	instanceTypes.forEach(function (dir) {
		var srcDir = path.join(moduleDir, dir);
		var destDir = path.join(baseDir, dir);

		if (fs.existsSync(srcDir)) {
			var files = fs.readdirSync(srcDir);
			files.forEach(function (fileName) {
				var srcPath = path.join(srcDir, fileName);
				var destPath = path.join(destDir, fileName);
				if (!fs.existsSync(destPath)) {
					fs.symlinkSync(srcPath, destPath);
				}
			});
		}
	});
};

/**
 * Register base entities for dataflo.ws processing.
 */
module.exports.register = function (instanceType, instanceName, instanceClass) {
	if (!registry[instanceType]) {
		console.warn(
			'Unexpected instance type. Predefined types is: ['+instanceTypes.join(', ')+']'
		);

		return;
	}

	registry[instanceType][instanceName] = instanceClass;
};



});