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@stormoz
Created January 19, 2016 01:16
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var Lazy = function (getFunc) {
var _value;
return {
get value() {
if(!_value){
_value = getFunc();
}
return _value;
}
};
};
var lazy = new Lazy(function(){
console.log('get func called');
return 1;
});
console.log(lazy.value); // function will be called just once
console.log(lazy.value);
var lazyRequire = function (modules) {
var lazy = {},
propertyName;
for(var i = 0; i < modules.length; i++) {
propertyName = getPropertyName(modules[i]);
Object.defineProperty(lazy, propertyName, {
get: getRequireFunc(modules[i])
});
}
return lazy;
function getRequireFunc(moduleName) {
return function(){
return require(moduleName);
}
}
function getPropertyName(moduleName){
var propertyName = "",
metDash = false;
for(var i = 0; i < moduleName.length; i++) {
if(moduleName[i] === '-') {
metDash = true;
continue;
}
propertyName += metDash ? moduleName[i].toUpperCase() : moduleName[i];
metDash = false;
}
return propertyName;
}
};
var packages = new lazyRequire(['fs', 'gulp-uglify']);
console.log(packages.fs.F_OK); // require for 'fs' module will be called here
console.log(packages.gulpUglify); // require for 'gulp-uglify' module will be called here
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