.___  .___.__          
  _____ ___.__. __| _/__| _/|  |   ____  
 /     <   |  |/ __ |/ __ | |  | _/ __ \ 
|  Y Y  \___  / /_/ / /_/ | |  |_\  ___/ 
|__|_|  / ____\____ \____ | |____/\___  >
      \/\/         \/    \/           \/ 

Context carrying Middleware for regular functions, with error handlers. Kinda like Connect/Express middleware but without the HTTP request/resonse. Or thinking about it another way, like async#applyEachSeries but with error functions.

Synopsis

var myddle = require('myddle');

myddle({}, [ fn1, fn2, ...], function(err) {
    // called when all functions have been called
});

Each middleware function has the signature:

function fn1(context, done) {
    // ... do something and store result in context
    return done();
}

And every single function will receive the context when called.

You can pass a context to start off with, or it will default to {}:

// equivalent
myddle({}, [ fn1, fn2, ...], function(err, context) {
    // ...
});

// same as above
myddle([ fn1, fn2, ...], function(err, context) {
    // ...
});

In all cases, the final function is called in the standard Node.js way, with err as the first argument. Whether err is set or not, the current context is always passed as the second argument.

Errors

If done() is called with an error, then the regular middleware functions are skipped over and any error handler middlewares are called with the error. Each error handler middleware has the following signature:

function fn1(err, context, done) {
    // ... do something and store result in context

    // to propagate the error (or send a new one), call done with it
    return done(err);

    // or

    // to cancel the error call done without any error
    return done();
}

Author

Written by Andrew Chilton - Blog - Twitter.

License

• Copyright 2013 Andrew Chilton. All rights reserved.

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