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ServletsFilter style request chaining.

Provides the filter pattern for web servers based on node.

The chain is configured in code, you can externalize it if you need.


Includes the filter-chain module's constructor

var FilterChain = require("filter-chain").FilterChain;

Load a set of filters (details below how to write filters)

var attributesFilter =      require("../server/attributes-filter"),
    logRequestFilter =      require("../server/log-request-filter")
    serverHeaderFilter =    require("../server/server-header-filter"),
    notModifiedFilter =     require("../server/not-modified-filter"),
    routerFilter =          require("../server/router");

Create an ordered array of the filters and pass it to the FilterChain constructor.

var chainModules = [

var chain = new FilterChain(chainModules);

Then, in a server start, the chain with it's execute() method, passing the request and response.

http.createServer(function(request, response) {
    // N.B a typical router should be in the chain
    //router.route(request, response);

    chain.execute(request, response);


That's it, nothing special, but a chaining is an essential design pattern that ought to be done in a consistent manner.

Writing filters

Filters look identical to Java Servlets filters.

var parse = require('url').parse;

filter = function(request, response, chain) {

    var url = parse(request.url);
    console.log(request.method + " " + url.pathname);

    chain.doFilter(request, response);


exports.filter = filter;

You must export a function called filter.

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