shibukawa/app.js

## app.js
var m = require("mithril");

m.mount(document.querySelector("#menu"), {
    view: function() {
        return m("ul", [
            m("li", m('a[href="/a"]', {config: m.route}, "module A")),
            m("li", m('a[href="/b"]', {config: m.route}, "module B")),
            m("li", m('a[href="/c"]', {config: m.route}, "module C"))
        ]);
    }
});

var loaded = {};

var lazyModuleA = {
    view: function (ctrl) {
        if (loaded.module_a) {
            return loaded.module_a;
        } else {
            m.startComputation();
            require(["./module_a.js"], function(module_a) {
                loaded.module_a = module_a;
                m.endComputation();
            });
        }
    }
};

var lazyModuleB = {
    view: function (ctrl) {
        if (loaded.module_b) {
            return loaded.module_b;
        } else {
            m.startComputation();
            require(["./module_b.js"], function(module_b) {
                loaded.module_b = module_b;
                m.endComputation();
            });
        }
    }
};

var lazyModuleC = {
    view: function (ctrl) {
        if (loaded.module_c) {
            return loaded.module_c;
        } else {
            m.startComputation();
            require(["./module_c.js"], function(module_c) {
                loaded.module_c = module_c;
                m.endComputation();
            });
        }
    }
};

m.route(document.querySelector("#content"), "/a", {
    "/a": lazyModuleA,
    "/b": lazyModuleB,
    "/c": lazyModuleC,
});

## index.html
<!DOCTYPE html>
<html>
    <meta charset="utf-8">
    <body>
        <div id="menu"></div>
        <div id="content"></div>
        <script src="js/app.js"></script>
    </body>
</html>

## module_a.js
var m = require("mithril");

console.log("module A is loaded");

module.exports = {
   view: function () {
       return m("h1", "module A");
   }
};

## module_b.js
var m = require("mithril");

console.log("module B is loaded");

module.exports = {
   view: function () {
       return m("h1", "module B");
   }
};

## module_c.js
var m = require("mithril");

console.log("module C is loaded");

module.exports = {
   view: function () {
       return m("h1", "module C");
   }
};

## webpack.config.js
module.exports = {
  entry: {
    app: "./src/app.js"
  },
  output: {
    path: "./js/",
    publicPath: "/js/",
    filename: "[name].js"
  },
  resolve: {
    extensions: ["", ".src", ".css"]
  }
};
	var m = require("mithril");

	m.mount(document.querySelector("#menu"), {
	view: function() {
	return m("ul", [
	m("li", m('a[href="/a"]', {config: m.route}, "module A")),
	m("li", m('a[href="/b"]', {config: m.route}, "module B")),
	m("li", m('a[href="/c"]', {config: m.route}, "module C"))
	]);
	}
	});

	var loaded = {};

	var lazyModuleA = {
	view: function (ctrl) {
	if (loaded.module_a) {
	return loaded.module_a;
	} else {
	m.startComputation();
	require(["./module_a.js"], function(module_a) {
	loaded.module_a = module_a;
	m.endComputation();
	});
	}
	}
	};

	var lazyModuleB = {
	view: function (ctrl) {
	if (loaded.module_b) {
	return loaded.module_b;
	} else {
	m.startComputation();
	require(["./module_b.js"], function(module_b) {
	loaded.module_b = module_b;
	m.endComputation();
	});
	}
	}
	};

	var lazyModuleC = {
	view: function (ctrl) {
	if (loaded.module_c) {
	return loaded.module_c;
	} else {
	m.startComputation();
	require(["./module_c.js"], function(module_c) {
	loaded.module_c = module_c;
	m.endComputation();
	});
	}
	}
	};

	m.route(document.querySelector("#content"), "/a", {
	"/a": lazyModuleA,
	"/b": lazyModuleB,
	"/c": lazyModuleC,
	});
	<!DOCTYPE html>
	<html>
	<meta charset="utf-8">
	<body>
	<div id="menu"></div>
	<div id="content"></div>
	<script src="js/app.js"></script>
	</body>
	</html>
	var m = require("mithril");

	console.log("module A is loaded");

	module.exports = {
	view: function () {
	return m("h1", "module A");
	}
	};
	var m = require("mithril");

	console.log("module B is loaded");

	module.exports = {
	view: function () {
	return m("h1", "module B");
	}
	};
	var m = require("mithril");

	console.log("module C is loaded");

	module.exports = {
	view: function () {
	return m("h1", "module C");
	}
	};
	module.exports = {
	entry: {
	app: "./src/app.js"
	},
	output: {
	path: "./js/",
	publicPath: "/js/",
	filename: "[name].js"
	},
	resolve: {
	extensions: ["", ".src", ".css"]
	}
	};