appex is a nodejs web application framework built around the TypeScript programming language and compiler. appex lets developers create and route http endpoints with TypeScript modules and functions, as well as providing nodejs developers similar reflection and type introspection services found in platforms such as .net.
//----------------------------------------------
// app.js
//----------------------------------------------
var appex = require('appex');
var app = appex({ program : './program.ts' });
app.listen(3000);
//----------------------------------------------
// program.ts
//----------------------------------------------
// http://localhost:3000/
export function index(context) {
context.response.send('home');
}
// http://localhost:3000/about
export function about(context) {
context.response.send('about');
}
// http://localhost:3000/(.*)
export function wildcard (context, path) {
context.response.send(404, path + " not found");
}
npm install appex
The following sections outline creating appex applications and configuration.
### create a applicationThe following code will create a standalone appex application and http server and listen on port 3000.
var appex = require('appex');
var app = appex({ program : './program.ts',
devmode : true,
logging : true });
app.listen(3000);
note: devmode and logging are optional. however, when developing with appex, it is helpful to have these enabled.
### start up optionsappex accepts the following start up options.
var options = {
// (required) location of source file.
program : './program.ts',
// (optional) recompile on request. (default:false)
devmode : true,
// (optional) log to stdout. (default:false)
logging : true,
// (optional) user defined objects added to the app context.
context : {}
};
var app = appex( options );
The following demonstrates setting up appex on an existing nodejs http server. In this example, appex will attempt to handle incoming requests, and if appex cannot route the request, will fire the callback.
var http = require('http');
var appex = require('appex');
var app = appex({ program : './program.ts' });
var server = http.createServer(function(req, res){
app(req, res, function() { // appex handler...
// not handled.
});
});
server.listen(3000);
appex allows developers to augment existing express / connect applications by way of middleware. The following demonstrates setting up appex as express middleware.
var express = require('express');
var appex = require('appex');
var app = express();
app.use( appex({ program : './program.ts' }) );
app.get('/', function(req, res) {
res.send('Hello World');
});
app.listen(3000);
Like in the "running on an existing http server" example above, appex will attempt to intercept incoming requests. if appex cannot find a matching route for the request, it will automatically call the "next" function to pass the request on to the next middleware or express handler.
in addition to this, appex may also act as traditional express middleware. In the example below, a appex wildcard function is created which will match "all" incoming requests, the wildcard function simply prints hello world to the console and then calls context.next(), which passes the request on the express handler.
//----------------------------------------------
// program.ts
//----------------------------------------------
// http:[host]:[port]/(.*)
export function wildcard(context, path) {
console.log('hello world!!');
context.next(); // pass it on!
}
//----------------------------------------------
// app.js
//----------------------------------------------
var express = require('express');
var appex = require('appex');
var app = express();
app.use( appex({ program : './program.ts' }) );
app.get('/', function(req, res) {
res.send('Hello World');
});
app.listen(3000);
Just like traditional express middleware, appex will also inheriate the characteristics of the request.
consider the following example in which the jade view engine is configured for use. appex will inheritate the response.render() method, which is passed to the appex handler as context.response.render()
//----------------------------------------------
// app.js
//----------------------------------------------
app.configure(function(){
app.set('views', __dirname + '/views');
// set up the jade engine.
app.set('view engine', 'jade');
// bind appex
app.use( appex({program:'./program.ts', devmode:true} ));
});
//----------------------------------------------
// program.ts
//----------------------------------------------
// http:[host]:[port]/
export function index(context) {
// jade renderer works!
context.response.render('index', { title: 'Express' });
}
The following section describes how to write http accessible functions with appex.
### app contextAll appex functions are passed a application context object as their first argument. The app context object encapulates the http request and response objects issued by the underlying http server, as well as additional objects specific to appex. These are listed below:
// the app context
export function method(context) {
// context.request - the http request object.
// context.response - the http response object.
// context.cascade - appex cascade.
// context.next - the next function (express middleware)
// context.router - the appex router
// context.template - the appex template engine.
// context.module - the module being run (this module)
// context.schema - json schema api.
// context.mime - a http mime type utility.
}
it is possible to extend the default objects passed on the context by adding them on the appex startup options. The following will attach the async module to the context.
//----------------------------------------------
// app.js
//----------------------------------------------
var appex = require('appex');
var app = appex({ program : './program.ts',
devmode : true,
context: {
async : require('async')
}});
app.listen(3000);
//----------------------------------------------
// program.ts
//----------------------------------------------
export function index(context) {
// context.async = passed on the context.
context.response.send('home page');
}
appex creates routes based on module scope and function name. consider the following:
export module services.customers {
// url: http://[host]:[port]/services/customers/insert
export function insert(context) { /* handle route */ }
// url: http://[host]:[port]/services/customers/update
export function update(context) { /* handle route */ }
// url: http://[host]:[port]/services/customers/delete
export function delete(context) { /* handle route */ }
}
// url: http://[host]:[port]/
export function index (context) { /* handle route */ }
// url: http://[host]:[port]/about
export function about (context) { /* handle route */ }
// url: http://[host]:[port]/contact
export function contact (context) { /* handle route */ }
// url: http://[host]:[port]/(.*)
export function wildcard (context, path) { /* handle route */ }
appex supports three function signatures for http routing (named, index and wildcard). Functions that do not apply these signatures will not be routed.
### named handlersNamed handlers resolve urls to their current module scope + the name of the function.
Named handlers require the following signature:
// http://[host]:[port]/about
export function about(context) {
context.response.send('about page');
}
// http://[host]:[port]/users/login
export module users {
export function login(context) {
context.response.send('handle login');
}
}
Index handlers resolve urls to their current module scope.
Index handlers require the following signature:
// url: http://[host]:[port]/
export function index(context) {
context.response.send('home page');
}
export module blogs {
// url: http://[host]:[port]/blogs
export function index (context)
{
context.response.send('blog index');
}
}
Wildcard handlers resolve their urls to their current module scope + url.
appex wildcard handlers allow for wildcard routing at a given module scope. Wildcard handlers support 'typed' url argument mapping, as denoted by the arguments annotation.
In addition, wildcard handlers also support optional arguments which can be specified with TypeScript's '?' on argument names.
appex wildcard handlers require the following signature:
declare var console;
export module blogs {
// url : http://[host]:[port]/blogs/2013/1/11 - matched
// url : http://[host]:[port]/blogs/2013/01/11 - matched
// url : http://[host]:[port]/blogs/2013/01/3rd - not matched - (see number annotation)
// url : http://[host]:[port]/blogs/2013/01 - matched - (see ? annotation)
// url : http://[host]:[port]/blogs/2013 - not matched - (month is required)
export function wildcard(context, year:number, month:number, day?:number) {
context.response.json({ year: year, month: month, day: day})
}
}
// url : http://[host]:[port]/
export function index(context) {
context.response.send('home');
}
// url : http://[host]:[port]/(.*)
export function wildcard(context, path) {
context.response.send(404, 'not found');
}
note: appex supports boolean, number, string and any annotations on wildcard arguments. if no annotation is specified, appex interprets the argument as a string. the type 'any' is also interpreted as string.
note: wildcard functions should be declared last in any module scope. this ensures other routes will be matched first.
### cascadesappex supports a cascading attribute scheme on modules and functions. With this, developers can apply arbituary meta data for modules and functions that will propagate through scope. appex has two special cascade properties for middleware and http verb matching, which are described below, however consider the following code which illustrates the concept.
declare function cascade (qualifier:string, obj:any);
cascade({a: 10}); // global.
cascade('foo', {b : 20})
export module foo {
cascade('foo.bar', {c : 30})
export module bar {
cascade('foo.bar.index', {d : 40})
export function index(context) {
//context.cascade
//{
// "a": 10,
// "b": 20,
// "c": 30,
// "d": 40
//}
context.response.json( context.cascade );
}
}
}
appex handles http verb matching with cascades. appex will recognise the 'verbs' property applied to the cascade to match against http verbs.
cascade('index', { verbs: ['get'] })
export function index (context) {
// only allow HTTP GET requests
context.response.send('index')
}
cascade('index', { verbs: ['post', 'put'] })
export function submit (context) {
// only allow HTTP POST and PUT requests
context.response.send('submit')
}
appex supports middleware with cascades. appex middleware defined with cascades allows developers to scope middleware on single functions, or entire module scopes. appex will recognise the 'use' property applied to the cascade to invoke middleware.
the following demonstrates how one might use middleware to secure a site admin.
note: middleware 'must' call next or handle the request.
declare function cascade (qualifier:string, obj:any);
declare var console;
function authenticate(context) {
console.log('authenticate')
// call next() if authenticated, otherwise, handle the response.
context.next();
}
function authorize(context) {
console.log('authorize')
// call next() if authorized, otherwise, handle the response.
context.next();
}
// apply security middleware to admin scope.
cascade('admin', {use: [authenticate, authorize]})
export module admin {
export function index(context) {
console.log(context.cascade); // view cascade
context.response.send('access granted!')
}
}
// index handler has no middleware applied.
export function index (context) {
console.log(context.cascade); // view cascade
context.response.send('home')
}
appex will only route functions prefixed with the TypeScript 'export' declarer. This rule also applied to modules. Developers can use this to infer notions of public and private at the http level.
consider the following example:
// module is not exported, and is therefore private.
module private_module {
// function is exported, yet private as a http endpoint due to the
// parent module being private.
export function public_method () { }
// function is not exported, and is private to this module.
function private_method() { }
}
// function is not exported, and is therefore private.
function private_function() { }
// function is exported, and therefore publically accessible.
export function public_function (context) {
// this function can invoke private functions.
private_function(); // ok
// calling exported method in private module
private_module.public_method(); // ok
// calling non exported method in private module
// private_module.private_method(); // bad
context.response.send('public_function');
}
Use wildcard functions to catch unhandled routes.
// http:[host]:[port]/
export function index (context) {
context.response.send('home page');
}
// http:[host]:[port]/(.*)
export function wildcard (context, path) {
context.response.send(404, path + ' not found');
}
Use wildcard functions with context.response.serve() to serve static content.
export module static {
// http:[host]:[port]/static/(.*)
export function wildcard(context, path) {
context.response.serve('./static/', path);
}
}
// http:[host]:[port]/
export function index (context) {
context.response.send('home page');
}
// http:[host]:[port]/(.*)
export function wildcard(context, path) {
context.response.send(404, path + ' not found');
}
appex comes bundled with a built in template engine which is modelled on the Microsoft Razor templating engine. The following sections outline its use.
### overviewThe appex template engine is available to all handlers by default. it is accessible on the context.template property. the following is an example of its use.
//----------------------------------------------
// view.txt
//----------------------------------------------
<ul>
@for(var n in context.users) {
@if(context.users[n].online) {
<li>@(context.users[n].name)</li>
}
}
</ul>
//----------------------------------------------
// program.ts
//----------------------------------------------
export function index(context) {
var users = [{name:'dave' , online : true},
{name:'smith', online : true},
{name:'jones', online : false},
{name:'alice', online : true}];
var text = context.template.render('./view.txt', { users: users });
context.response.headers['Content-Type'] = 'text/html';
context.response.send(text);
}
each template is passed a data context. this context allows the caller to send data to the template for rendering. the context parameter is optional. the example below is sending the users array to the template context for rendering.
export function index(context) {
var users = [{name:'dave' , online : true},
{name:'smith', online : true},
{name:'jones', online : false},
{name:'alice', online : true}];
context.response.send(context.template.render('./view.txt', { users: users }));
}
appex templates support the following statements and syntax
if statments are supported.
@if(expression) {
some content
}
@if(a > 10) {
some content
}
@(user.loggedin) {
<span>welcome</span>
}
the following for loops are supported.
@for(var i = i; i < 100; i++) {
@(i)
}
@for(var n in list) {
@(list[n])
}
will emit the value contained.
@('hello world')
@(123)
@(some_variable)
code blocks can be useful for adding template side rendering logic.
@{
var message = 'hello'
}
@(message)
@*
this comment will not be rendered!
*@
appex templates support template inheritance.
consider the following where layout.txt defines the sections 'header' and 'content' and the view.txt overrides these sections with its own content.
//----------------------------------------------
// layout.txt
//----------------------------------------------
<html>
<head>
@section header
</head>
<body>
@section content {
<span>some default content</span>
}
</body>
</html>
//----------------------------------------------
// view.txt
//----------------------------------------------
@layout 'layout.txt'
@section header {
<title>my page</title>
}
@section content {
<p>overriding the layout.txt content section.</p>
<ul>
@for(var n in context.users) {
@if(context.users[n].online) {
<li>@(context.users[n].name)</li>
}
}
</ul>
}
//----------------------------------------------
// program.ts
//----------------------------------------------
export function index(context) {
var users = [{name:'dave' , online : true},
{name:'smith', online : true},
{name:'jones', online : false},
{name:'alice', online : true}];
var text = context.template.render('./view.txt', { users: users });
context.response.send(text);
}
note : when specifying a layout, the view will only render content within the layouts section placeholders.
### renderappex templates also allow for partial views with the @render statment. consider the following which renders the nav.txt file into the layout.txt file.
//----------------------------------------------
// nav.txt
//----------------------------------------------
<ul>
<li>home</li>
<li>about</li>
<li>contact</li>
</ul>
//----------------------------------------------
// layout.txt
//----------------------------------------------
<html>
<head>
@section header
</head>
<body>
@render 'nav.txt'
@section content {
<span>some default content</span>
}
</body>
</html>
//----------------------------------------------
// view.txt
//----------------------------------------------
@layout 'layout.txt'
@section header {
<title>my page</title>
}
@section content {
<p>overriding the layout.txt content section.</p>
<ul>
@for(var n in context.users) {
@if(context.users[n].online) {
<li>@(context.users[n].name)</li>
}
}
</ul>
}
//----------------------------------------------
// program.ts
//----------------------------------------------
export function index(context) {
var users = [{name:'dave' , online : true},
{name:'smith', online : true},
{name:'jones', online : false},
{name:'alice', online : true}];
var text = context.template.render('./view.txt', { users: users });
context.response.send(text);
}
appex template content is not cached (the implementor is expected to handle their own caching) however the generated template code is.
appex templates do inheriate the behaviour of the appex 'devmode' option. setting devmode to 'true' will cause template code to be reloaded from disk and code generated with each request. setting devmode to false will load content from disk on first request, and cache the generated template code in memory for the lifetime of the application.
in addition to this, a implementation where the devmode is false can override the caching behaviour with the following.
export function index(context) {
// manually override the template devmode option.
context.template.option.devmode = true;
context.response.send(context.template.render('./view.txt'))
}
appex provides functionality for generating json schemas from TypeScript classes and interfaces as well as tools for validating json data.
### generating schemaThe following demonstrates generating json schema from the following class hierarchy.
export module model {
/** a product */
export class Product {
/** the product name */
public name : string;
/** the product description */
public description : string;
/** the product cost */
public cost : number;
}
/** a order */
export class Order {
/** the product being ordered */
public products : Product;
}
/** a customer */
export class Customer {
/** the customers firstname */
public firstname : string;
/** the customers lastname */
public lastname : string;
/** orders made by this customer */
public orders : Order[];
}
}
export function index (context:appex.web.IContext) {
// pass the fully qualified name of the type.
var schema = context.schema.generate('model.Customer');
context.response.json(schema);
}
which generates the following json schema.
{
"id": "model.Customer",
"type": "object",
"description": "a customer",
"properties": {
"firstname": {
"type": "string",
"description": "the customers firstname",
"required": true
},
"lastname": {
"type": "string",
"description": "the customers lastname",
"required": true
},
"orders": {
"type": "array",
"items": {
"type": {
"id": "model.Order",
"type": "object",
"description": "a order",
"properties": {
"products": {
"id": "model.Product",
"type": "object",
"description": "a product",
"properties": {
"name": {
"type": "string",
"description": "the product name",
"required": true
},
"description": {
"type": "string",
"description": "the product description",
"required": true
},
"cost": {
"type": "number",
"description": "the product cost",
"required": true
}
},
"required": true
}
}
}
},
"description": "orders made by this customer",
"required": true
}
}
}
a quick note...
when generating schema from classes:
when generating schema from interfaces:
appex supports json schema validation from class and interface definitions. consider the following...
interface Customer {
firstname : string;
lastname : string;
age : number;
emails : string[];
option_a ? : boolean; // optional
option_b ? : boolean; // optional
}
export function index(context) {
// a customer with invalid data.
var customer = {
firstname : 'dave',
age : '33',
emails : [12345, 'dave@domain.com', true],
option_b : 1,
option_c : 1
}
// do validation.
var errors = context.schema.validate('Customer', customer);
if(errors) {
context.response.json(errors);
}
}
will output the following.
[
{
"message": "instance.lastname is required."
},
{
"message": "instance.age is not a number"
},
{
"message": "instance.emails[0] is not a string"
},
{
"message": "instance.emails[2] is not a string"
},
{
"message": "instance.option_b is not a boolean"
},
{
"message": "instance.option_c unexpected property"
}
]
appex provides a reflection api derived from TypeScript's type system that developers can leverage to reflect type information declared throughout their appex modules.
the following section outlines how to use the reflection api.
### reflect everythingthe appex reflection api is passed on the context.module.reflection property and is available to all appex handler methods. The following code will JSON serialize everything declared in your appex project and write it to the http response.
export function index (context:appex.web.Context) {
context.response.json( context.module.reflection );
}
In typical scenarios, developers will want to leverage reflection meta data to generate service contacts and client side models. the reflection api lets you access meta data for the following types declared in your project.
to access specific type metadata, use the reflection.get([qualifier]) method, as demonstrated below.
export module model {
export class Customer {
public firstname : string;
public lastname : string;
public age : number;
}
}
export function index (context:appex.web.Context) {
context.response.json( context.module.reflection.get('model.Customer') );
}
and methods..
function some_method(a:string, b:number, c?:boolean) : void { }
export function index (context:appex.web.Context) {
context.response.json( context.module.reflection.get('some_method') );
}
....and variables...
var some_variable:number = 10;
export function index (context:appex.web.Context) {
context.response.json( context.module.reflection.get('some_variable') );
}
This section outlines development with appex.
### appex.d.ts declarationIf you develop on a TypeScript complicant editor (one that supports TS 0.9), appex comes bundled with a declaration file you can reference in your project. If installing appex via npm, your reference should be as follows.
/// <reference path="node_modules/appex/appex.d.ts" />
export function index (context:appex.web.IContext) {
context.response.send('hello');
}
export function wildcard(context:appex.web.IContext, path:string) {
context.response.serve('./', path);
}
By referencing this in your project, you get the benefits of code completion and static type checking against both appex, and the nodejs core.
Additional declaration files may be obtained from here
### structuring projectsappex includes TypeScript's ability to reference source files with the 'reference' element. appex will traverse each source files references and include it as part of the compilation.
Developers can use this functionality to logically split source files into reusable components of functionality, as demonstrated below.
//---------------------------------------------------
// file: app.js
//---------------------------------------------------
var appex = require('appex');
var app = appex ({ program : './index.ts' });
app.listen(3000);
//---------------------------------------------------
// file: index.ts
//---------------------------------------------------
/// <reference path="users.ts" />
/// <reference path="pages.ts" />
//---------------------------------------------------
// file: users.ts
//---------------------------------------------------
export module users {
// http://[host]:[port]/users/login
export function login (context) { context.response.send('users.login') }
// http://[host]:[port]/users/logout
export function logout (context) { context.response.send('users.logout') }
}
//---------------------------------------------------
// file: pages.ts
//---------------------------------------------------
// http://[host]:[port]/
export function index (context) { context.response.send('home') }
// http://[host]:[port]/about
export function about (context) { context.response.send('about') }
// http://[host]:[port]/contact
export function contact (context) { context.response.send('contact') }
export function wildcard (context, path) { context.response.send(404, ' not found') }
The MIT License (MIT)
Copyright (c) 2013 Haydn Paterson (sinclair) haydn.developer@gmail.com
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
FAQs
develop nodejs web applications with typescript
We found that appex demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
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