SpontaneousCMS/spontaneous

// Parts copyright Modernizr:
// * @author        Faruk Ates
// * @author        Paul Irish
// * @copyright     (c) 2009-2011 Faruk Ates.
// * @contributor   Ben Alman

// many thanks to modernizer for working a lot of this out
// should probably just use it instead...
// this does two things:
// 1. Check that the current browser supports the core HTML5 feature set,
// 2. Regularise access to the various APIs, removing vendor prefixes and providing the spec defined methods
// 3. Add some useful CSS-visible attributes to the HTML element
(function() {
    'use strict';
    var _window = window, _document = document;
    var testFlexBoxCompatibility = false;
    var i, ii;
    var prefixes = ' -webkit- -moz- -o- -ms- -khtml- '.split(' ');
    try {

        ///////////////////////////// Flexible Box model
        var set_prefixed_property_css = function(element, property, value, extra) {
            element.style.cssText = prefixes.join(property + ':' + value + ';') + (extra || '');
        };

        var set_prefixed_value_css = function(element, property, value, extra) {
            property += ':';
            element.style.cssText = (property + prefixes.join(value + ';' + property)).slice(0, -property.length) + (extra || '');
        };


        if (testFlexBoxCompatibility) {
            var docElement = _document.documentElement,
            c = _document.createElement('div'),
            elem = _document.createElement('div'),
            w;

            set_prefixed_value_css(c, 'display', 'box', 'width:42px;padding:0;');
            set_prefixed_property_css(elem, 'box-flex', '1', 'width:10px;');

            c.appendChild(elem);
            docElement.appendChild(c);
            w = elem.offsetWidth;
            c.removeChild(elem);
            docElement.removeChild(c);

            if (w !== 42) {
                // console.error(w)
                throw (w) + ' Flexible Box Model not supported';
            }
        }

        ///////////////////////////// XHR Uploads
        var xhr = new XMLHttpRequest();
        if (!xhr.upload) {
            throw 'XMLHttpRequestUpload not supported';
        }

        ///////////////////////////// FormData
        try {
            var f = new FormData();
        } catch (e) {
            throw 'FormData not supported';
        }

        ///////////////////////////// File API / File objects
        if (!_window.File) {
            throw 'File API not supported';
        }

        ///////////////////////////// File API / objectURLs
        // provide consistent API for creating blob/object URLs
        var createObjectURL = 'createObjectURL', revokeObjectURL = 'revokeObjectURL';
        if (!_window.URL) {
            if (_window.webkitURL) {
                _window.URL = _window.webkitURL;
            } else {
                _window.URL = {};
                if (_window.createBlobURL) {
                    _window.URL[createObjectURL] = function(file) {
                        return _window.createBlobURL(file);
                    };
                } else if (_window[createObjectURL]) {
                    _window.URL[createObjectURL] = function(file) {
                        return _window[createObjectURL](file);
                    };
                } else {
                    //// Dont fail this because it's not absolutely essential
                    //// & fails iOS devices (though that might be a good thing in some ways, it
                    //// would seriously limit users ability to make quick changes on the go, for instance)
                    _window.URL[createObjectURL] = function(file) {
                        return '';
                    };
                    // throw "File API not supported";
                }
                if (_window.revokeBlobURL) {
                    _window.URL[revokeObjectURL] = function(file) {
                        return _window.revokeBlobURL(file);
                    };
                } else if (_window[revokeObjectURL]) {
                    _window.URL[revokeObjectURL] = function(file) {
                        return _window[revokeObjectURL](file);
                    };
                } else {
                    //// Dont fail this because it's not absolutely essential
                    //// & fails iOS devices (though that might be a good thing in some ways, it
                    //// would seriously limit users ability to make quick changes on the go, for instance)
                    _window.URL[revokeObjectURL] = function(file) {
                        return '';
                    };
                    // throw "File API not supported";
                }
            }
        }
        ///////////////////////////// File API / slices
        // normalise access to the File#slice method
        var proto = _window.File.prototype;
        if (!proto.slice) {
            var methods = ['webkitSlice', 'mozSlice'];
            for (i = 0, ii = methods.length; i < ii; i++) {
                var method = methods[i];
                if (proto[method]) { proto.slice = proto[method]; }
            }
            if (!proto.slice) {
                // not supporting slice just means we can't use the sharded uploader
            }
        }



        ///////////////////////////// localStorage
        try {
            i = localStorage.getItem;
        } catch(e) {
            throw 'Local Storage not supported';
        }

        var b = _document.documentElement;
        b.setAttribute('data-useragent', navigator.userAgent);
        b.setAttribute('data-platform', navigator.platform);
    } catch (e) {
        _window.location.href = '/@spontaneous/unsupported?msg=' + _window.encodeURIComponent(e) + '&useragent=' + _window.encodeURIComponent(_window.navigator.userAgent);
    }
}());