dta/dta.js

Dynamically typed arguments for javascript

/*jslint node:true, browser:true*/
/*globals define, toString*/
// Wrapper for supporting Node, Browsers and AMD
(function (define) {
    'use strict';

    var findPrototype, isArguments, dta;

    // code from underscore: https://github.com/jashkenas/underscore/blob/master/underscore.js
    isArguments = function isArguments(obj) {
        return toString.call(obj) === '[object Arguments]';
    };
    if (!isArguments(arguments)) {
        isArguments = function (obj) {
            return obj && obj.hasOwnProperty('callee');
        };
    }

    findPrototype = function findPrototype(translator, result, elem) {
        var hash, tmpName;

        for (hash in translator.prototypes) {
            if (translator.prototypes.hasOwnProperty(hash)) {
                if (translator.prototypes[hash].prototype && translator.prototypes[hash].prototype.isPrototypeOf(elem)) {
                    if (!translator[hash] || translator[hash].length === 0) {
                        throw new Error('Can not handle argument');
                    }
                    tmpName = translator[hash].splice(0, 1)[0];
                    if (tmpName.substr(-1) === ']' && tmpName.substr(0, 1) === '[') {
                        translator[hash].unshift(tmpName);
                        tmpName = tmpName.substring(1, tmpName.length - 1);
                        result[tmpName] = result[tmpName] || [];
                        result[tmpName].push(elem);
                    } else {
                        result[tmpName] = elem;
                    }
                    return true;
                }
            }
        }
        return false;
    };
    dta = function dta(translator, arrOrFn) {
        var i, hash, result, tmpName, tmpType;

        if ((isArguments(translator) || Array.prototype.isPrototypeOf(translator)) && (!isArguments(arrOrFn) || !Array.prototype.isPrototypeOf(arrOrFn))) { // Change order if valid
            tmpType = translator;
            translator = arrOrFn;
            arrOrFn = tmpType;
        }
        if (typeof translator !== 'object') {
            throw new Error('Can not handle translator object');
        }

        translator.prototypes = translator.prototypes || {};
        translator.prototypes.array = translator.prototypes.array || Array;
        translator.prototypes.error = translator.prototypes.error || Error;
        translator.prototypes.regExp = translator.prototypes.regExp || RegExp;
        result = {};

        for (hash in translator) {
            if (translator.hasOwnProperty(hash) && hash !== 'prototypes') {
                if (typeof translator[hash] === 'string') {
                    translator[hash] = [translator[hash]];
                }
            }
        }

        translator.mandatory = translator.mandatory || [];

        if (typeof arrOrFn === 'function') {
            return function () {
                return arrOrFn(dta(translator, arguments));
            };
        }
        if (isArguments(arrOrFn) || Array.prototype.isPrototypeOf(arrOrFn)) {
            for (i = 0; i < arrOrFn.length; i += 1) {
                tmpType = typeof arrOrFn[i];

                if (tmpType === 'object') {
                    // This could be a lot of prototypes or just an object
                    if (!findPrototype(translator, result, arrOrFn[i])) {
                        if (isArguments(arrOrFn[i])) {
                            tmpType = 'argument';
                        }
                        if (!translator[tmpType] || translator[tmpType].length === 0) {
                            throw new Error('Can not handle argument number ' + i);
                        }
                        tmpName = translator[tmpType].splice(0, 1)[0];
                        if (tmpName.substr(-1) === ']' && tmpName.substr(0, 1) === '[') {
                            translator[tmpType].unshift(tmpName);
                            tmpName = tmpName.substring(1, tmpName.length - 1);
                            result[tmpName] = result[tmpName] || [];
                            result[tmpName].push(arrOrFn[i]);
                        } else {
                            result[tmpName] = arrOrFn[i];
                        }
                    }
                } else {
                    if (!translator[tmpType] || translator[tmpType].length === 0) {
                        throw new Error('Can not handle argument number ' + i);
                    }
                    tmpName = translator[tmpType].splice(0, 1)[0];
                    if (tmpName.substr(-1) === ']' && tmpName.substr(0, 1) === '[') {
                        translator[tmpType].unshift(tmpName);
                        tmpName = tmpName.substring(1, tmpName.length - 1);
                        result[tmpName] = result[tmpName] || [];
                        result[tmpName].push(arrOrFn[i]);
                    } else {
                        result[tmpName] = arrOrFn[i];
                    }
                }
            }

            for (i = 0; i < translator.mandatory.length; i += 1) {
                if (!result.hasOwnProperty(translator.mandatory[i])) {
                    throw new Error('\'' + translator.mandatory[i] + '\' is mandatory, but not set.');
                }
            }
            return result;
        }

        throw new Error('Can not handle arguments');
    };

    define('dta', function () {
        return dta;
    });
}(typeof define === 'function' && define.amd ? define : function (id, factory) {
    'use strict';
    if (typeof module !== 'undefined' && typeof exports !== 'undefined') {
        //commonjs
        module.exports = factory();
    } else {
        // global
        window[id] = factory();
    }
}));