/*
The MIT License (MIT)
Copyright (c) 2014-2020 Nikolai Suslov and the Krestianstvo.org project contributors. (https://github.com/NikolaySuslov/livecodingspace/blob/master/LICENSE.md)
Virtual World Framework Apache 2.0 license (https://github.com/NikolaySuslov/livecodingspace/blob/master/licenses/LICENSE_VWF.md)
*/
/// Kernel utility functions.
///
/// @module vwf/utility
class Utility {
constructor() {
//console.log("Utility constructor");
let self = this;
// -- transforms ---------------------------------------------------------------------------
/// Transformation functions for vwf.utility.transform. Invoke these as:
///
/// utility.transform( object, utility.transforms.*transform* )
///
/// to apply the transform utility.transforms.*transform* to object.
this.transforms = {
// -- transit --------------------------------------------------------------------------
/// A vwf.utility.transform transformation function to convert an object for proper JSON
/// serialization. Array-like objects are converted to actual Arrays. All other objects
/// are unchanged. Invoke as: utility.transform( object, utility.transforms.transit ).
///
/// @param {Object} object
/// The object being transformed or one of its descendants.
///
/// @returns {Object}
/// An Array-like converted to an Array, or *object*.
transit: function( object ) {
// Determine if an object is Array-like (but not an Array) to identify objects that
// need to be converted to Arrays for normalization.
function isArraylike( candidate ) {
var arraylike = false;
// Filter with typeof and instanceof since they're much faster than toString().
// Then check for typed arrays (Int8Array, Uint8Array, ...) or the Arguments
// object using the type string.
if ( typeof candidate == "object" && candidate != null && ! ( candidate instanceof Array ) ) {
var typeString = Object.prototype.toString.call( candidate ) // eg, "[object *Type*]"
arraylike = ( typeString.slice( -6 ) == "Array]" || typeString == "[object Arguments]" );
}
return arraylike;
};
// Convert typed arrays to regular arrays.
return isArraylike( object ) ?
Array.prototype.slice.call( object ) : object;
},
// -- hash -----------------------------------------------------------------------------
/// A vwf.utility.transform transformation function to normalize an object so that it
/// can be serialized and hashed with consistent results. Numeric precision is reduced
/// to match the precision retained by the reflector. Non-Array objects are reordered so
/// that their keys are in alphabetic order. Other objects are unchanged. Invoke as:
/// utility.transform( object, utility.transforms.hash ).
///
/// @param {Object} object
/// The object being transformed or one of its descendants.
///
/// @returns {Object}
/// A reduced-precision number, an Object with alphabetic keys, or *object*.
hash: function( object ) {
// Apply the `transit` transform first to convert Array-likes into Arrays.
object = exports.transforms.transit( object );
// Reduce numeric precision slightly to match what passes through the reflector.
if ( typeof object == "number" ) {
return Number( object.toPrecision(15) );
}
// Order objects alphabetically.
else if ( typeof object == "object" && object != null && ! ( object instanceof Array ) ) {
var ordered = {};
Object.keys( object ).sort().forEach( function( key ) {
ordered[key] = object[key];
} );
return ordered;
}
return object;
},
}
}
// -- transform ----------------------------------------------------------------------------
/// Recursively transform an arbitrary object using the provided transformation function.
/// Containers are duplicated where necessary so that the original object and any contained
/// objects are not modified. Unchanged objects will be referenced directly in the result.
///
/// @param {Object} object
/// The object to transform. `Object` and `Array` contents are recursively transformed
/// using the same transformation function.
/// @param {Function} transformation
/// The transformation function: `function( object, names, depth, finished ) { return object }`
/// Call `finished()` from the transformation function to stop recursion for the current
/// object.
/// @param {(Number|String)[]} [names]
/// Array of the names or indexes that refer to `object` in its container and in its
/// containers' containers, parent first (recursive calls only).
/// @param {Number} [depth]
/// Recursion depth (recursive calls only).
///
/// @returns {Object}
/// The transformed object.
transform ( object, transformation /* ( object, names, depth, finished ) */, names, depth ) {
names = names || [];
depth = depth || 0;
var finished = false, item;
var result = object = transformation( object, names, depth, function() { finished = true } );
if ( typeof object === "object" && object !== null && ! finished ) {
if ( object instanceof Array ) {
// Recursively transform the elements if the object is an Array.
for ( var index = 0; index < object.length; index++ ) {
if ( ( item = this.transform( object[index], transformation,
[ index ].concat( names ), depth + 1 ) ) !== object[index] ) {
// If the item changed, and it's the first change in the array, then
// duplicate the array.
if ( result === object ) {
result = [].concat( object ); // shallow copy into a new Array
}
// Assign the transformed item.
result[index] = item;
}
}
} else {
// Recursively transform the properties if the object is an Object.
Object.keys( object ).forEach( function( key ) {
if ( ( item = this.transform( object[key], transformation,
[ key ].concat( names ), depth + 1 ) ) !== object[key] ) {
// If the item changed, and it's the first change in the object, then
// duplicate the object.
if ( result === object ) {
result = {};
Object.keys( object ).forEach( function( k ) {
result[ k ] = object[ k ]; // shallow copy into a new Object
} );
// Also copy the non-enumerable `length` property for an `arguments`
// object.
var lengthDescriptor = Object.getOwnPropertyDescriptor( object, "length" );
if ( lengthDescriptor && ! lengthDescriptor.enumerable ) {
Object.defineProperty( result, "length", lengthDescriptor );
}
}
// Assign the transformed item.
result[key] = item;
}
}, this );
}
}
return result;
}
// -- exceptionMessage ---------------------------------------------------------------------
/// Format the stack trace for readability.
///
/// @param {Error} error
/// An Error object, generally provided by a catch statement.
///
/// @returns {String}
/// An error message that may be written to the console or a log.
exceptionMessage ( error ) {
// https://github.com/eriwen/javascript-stacktrace sniffs the browser type from the
// exception this way.
if ( error.arguments && error.stack ) { // Chrome
return "\n " + error.stack;
} else if ( window && window.opera ) { // Opera
return error.toString();
} else if ( error.stack ) { // Firefox
return "\n " + error.toString() + "\n" + // somewhat like Chrome's
error.stack.replace( /^/mg, " " );
} else { // default
return error.toString();
}
}
// -- resolveURI ---------------------------------------------------------------------------
/// Convert a relative URI to an absolute URI.
///
/// @param {String} uri
/// The URI to resolve. If uri is relative, it will be interpreted with respect to
/// baseURI, or with respect to the document if baseURI is not provided.
/// @param {String} [baseURI]
/// An optional URI that provides the reference for uri. If baseURI is not provided, uri
/// will be interpreted with respect to the document. If baseURI is relative, it will be
/// interpreted with respect to the document before resolving uri.
///
/// @returns {String}
/// uri as an absolute URI.
resolveURI ( uri, baseURI ) {
var doc = document;
// if ( baseURI ) {
// // Create a temporary document anchored at baseURI.
// var doc = document.implementation.createHTMLDocument( "resolveURI" );
// // Insert a with the reference URI: .
// var base = doc.createElement( "base" );
// base.href = this.resolveURI( baseURI ); // resolve wrt the document
// var head = doc.getElementsByTagName( "head" )[0];
// head.appendChild( base );
// }
// Create an and resolve the URI.
// var a = doc.createElement( "a" );
// a.href = uri;
// return a.href;
return uri
}
// -- merge --------------------------------------------------------------------------------
/// Merge fields from the `source` objects into `target`.
merge ( target /* [, source1 [, source2 ... ] ] */ ) {
for ( var index = 1; index < arguments.length; index++ ) {
var source = arguments[index];
Object.keys( source ).forEach( function( key ) {
if ( source[key] !== undefined ) {
target[key] = source[key];
}
} );
}
return target;
}
validObject ( obj ) {
var objType = ( {} ).toString.call( obj ).match( /\s([a-zA-Z]+)/ )[ 1 ].toLowerCase();
return ( objType != 'null' && objType != 'undefined' );
}
hasFileType ( value ) {
return ( this.fileType( value ) !== undefined )
}
fileType ( filename ) {
var fileFormat = undefined;
var temp = filename.split( '.' );
if ( temp.length > 1 ) {
fileFormat = temp.pop();
if ( fileFormat.length > 5 ) {
fileFormat = undefined;
}
}
return fileFormat;
}
ifPrototypeGetId ( appID, prototypes, nodeID, childID ) {
var prototypeID = undefined;
if ( ( nodeID == 0 && childID != appID ) || prototypes[ nodeID ] !== undefined ) {
if ( nodeID != 0 || childID != appID ) {
prototypeID = nodeID ? nodeID : childID;
if ( prototypes[ prototypeID ] !== undefined ) {
prototypeID = childID;
}
return prototypeID;
}
}
return undefined;
}
isString ( s ) {
return ( typeof( s ) === 'string' || s instanceof String );
}
isFunction ( obj ) {
return ( typeof obj === 'function' || obj instanceof Function );
}
}
export {
Utility
}