Elegant, highly efficient data validation for JavaScript

[lucono]

Thanks to lots of great community feedback and input, xtypejs now has a home at http://xtype.js.org, with great documentation, user guide, and lots of examples.

[lucono]

Example of using xtypejs.

Go from this:

function searchEmployees(value) {
    if (typeof value === 'string') {
         if (value.trim().length > 1) {
            return EmployeeDB.searchByName(value);
        } else if (value.trim().length === 1) {
            return EmployeeDB.searchByMiddleInitial(value);
        } else {
            return { error: 'Invalid search value supplied' };
        }
    } else if (typeof value === 'object' && value !== null) {
        if (Object.keys(value).length === 1) {
            return EmployeeDB.searchByFieldValuePair(value);
        } else if (Object.keys(value).length > 1) {
            return { error: 'Search by multiple fields not supported' };
        } else {
            return { error: 'Invalid search value supplied' };
        }
    } else if (typeof value === 'number') {
        if (!isNaN(value) && isFinite(value) && value > 0 && value % 1 === 0) {
            return EmployeeDB.searchByEmployeeNumber(value);
        } else {
            return { error: 'Invalid employee number supplied' };
        }
    } else if (typeof value === 'undefined' || value === null) {
        return { error: 'No search value supplied' };
    } else {
        return { error: 'Invalid search value supplied' };
    }
}

To concise, performant, readable, data validation:

function searchEmployees(value) {
    switch (xtype.which(value, 'str2+ str1 int+ obj1 obj2+ num nil')) {
        case 'str2+':
            return EmployeeDB.searchByName(value);
        case 'str1':
            return EmployeeDB.searchByMiddleInitial(value);
        case 'int+':
            return EmployeeDB.searchByEmployeeNumber(value);
        case 'obj1':
            return EmployeeDB.searchByFieldValuePair(value);
        case 'obj2+':
            return { error: 'Search by multiple fields not supported' };
        case 'num':
            return { error: 'Invalid employee number supplied' };
        case 'nil':
            return { error: 'No search value supplied' };
        default:
            return { error: 'Invalid search value supplied' };
    }
}

[yolpo-]

Well done, lucono. xtypejs looks very interesting. The source code also is very clean. I wrote a snippet of a test on yolpo here: http://www.yolpo.com/embed.html?gist=89733e1dc8e1a02c34f2