1. module koa-router
   1. function koa-router (opts)
   2. function koa-router.layer (path, methods, middleware, opts)
   3. function koa-router.url (path, params)
   4. object koa-router.layer.prototype
2. module koa-router.layer
   1. function koa-router.layer (path, methods, middleware, opts)
3. module koa-router.layer.prototype
   1. function koa-router.layer.prototype.captures (path)
   2. function koa-router.layer.prototype.match (path)
   3. function koa-router.layer.prototype.param (param, fn)
   4. function koa-router.layer.prototype.params (path, captures, existingParams)
   5. function koa-router.layer.prototype.setPrefix (prefix)
   6. function koa-router.layer.prototype.url (params)

module koa-router

function koa-router (opts)

• description and source-code

  function Router(opts) {
    if (!(this instanceof Router)) {
      return new Router(opts);
    }
  
    this.opts = opts || {};
    this.methods = this.opts.methods || [
      'HEAD',
      'OPTIONS',
      'GET',
      'PUT',
      'PATCH',
      'POST',
      'DELETE'
    ];
  
    this.params = {};
    this.stack = [];
  }

• example usage

  n/a

function koa-router.layer (path, methods, middleware, opts)

• description and source-code

  function Layer(path, methods, middleware, opts) {
    this.opts = opts || {};
    this.name = this.opts.name || null;
    this.methods = [];
    this.paramNames = [];
    this.stack = Array.isArray(middleware) ? middleware : [middleware];
  
    methods.forEach(function(method) {
      var l = this.methods.push(method.toUpperCase());
      if (this.methods[l-1] === 'GET') {
        this.methods.unshift('HEAD');
      }
    }, this);
  
    // ensure middleware is a function
    this.stack.forEach(function(fn) {
      var type = (typeof fn);
      if (type !== 'function') {
        throw new Error(
          methods.toString() + " `" + (this.opts.name || path) +"`: `middleware` "
          + "must be a function, not `" + type + "`"
        );
      }
    }, this);
  
    this.path = path;
    this.regexp = pathToRegExp(path, this.paramNames, this.opts);
  
    debug('defined route %s %s', this.methods, this.opts.prefix + this.path);
  }

• example usage

  n/a

function koa-router.url (path, params)

• description and source-code

  url = function (path, params) {
      return Layer.prototype.url.call({path: path}, params);
  }

• example usage

  ...
  ## 5.4.0
  
  - Expose matched route at `ctx._matchedRoute`.
  
  ## 5.3.0
  
  - Register multiple routes with array of paths [#203](https://github.com/alexmingoia/koa-router/issue/143).
  - Improved router.url() [#143](https://github.com/alexmingoia/koa-router/pull/143)
  - Adds support for named routes and regular expressions
    [#152](https://github.com/alexmingoia/koa-router/pull/152)
  - Add support for custom throw functions for 405 and 501 responses [#206](https://github.com/alexmingoia/koa-router/pull/206)
  
  ## 5.2.3
  
  - Fix for middleware running twice when nesting routes [#184](https://github.com/alexmingoia/koa-router/issues/184)
  ...

module koa-router.layer

function koa-router.layer (path, methods, middleware, opts)

• description and source-code

  function Layer(path, methods, middleware, opts) {
    this.opts = opts || {};
    this.name = this.opts.name || null;
    this.methods = [];
    this.paramNames = [];
    this.stack = Array.isArray(middleware) ? middleware : [middleware];
  
    methods.forEach(function(method) {
      var l = this.methods.push(method.toUpperCase());
      if (this.methods[l-1] === 'GET') {
        this.methods.unshift('HEAD');
      }
    }, this);
  
    // ensure middleware is a function
    this.stack.forEach(function(fn) {
      var type = (typeof fn);
      if (type !== 'function') {
        throw new Error(
          methods.toString() + " `" + (this.opts.name || path) +"`: `middleware` "
          + "must be a function, not `" + type + "`"
        );
      }
    }, this);
  
    this.path = path;
    this.regexp = pathToRegExp(path, this.paramNames, this.opts);
  
    debug('defined route %s %s', this.methods, this.opts.prefix + this.path);
  }

• example usage

  n/a

module koa-router.layer.prototype

function koa-router.layer.prototype.captures (path)

• description and source-code

  captures = function (path) {
    if (this.opts.ignoreCaptures) return [];
    return path.match(this.regexp).slice(1);
  }

• example usage

  ...
  if (!matched.route) return next();
  
  var mostSpecificPath = matched.pathAndMethod[matched.pathAndMethod.length - 1].path;
  ctx._matchedRoute = mostSpecificPath;
  
  layerChain = matched.pathAndMethod.reduce(function(memo, layer) {
    memo.push(function(ctx, next) {
      ctx.captures = layer.captures(path, ctx.captures);
      ctx.params = layer.params(path, ctx.captures, ctx.params);
      return next();
    });
    return memo.concat(layer.stack);
  }, []);
  
  return compose(layerChain)(ctx, next);
  ...

function koa-router.layer.prototype.match (path)

• description and source-code

  match = function (path) {
    return this.regexp.test(path);
  }

• example usage

  ...
  
  Private API changed to separate context parameter decoration from route
  matching. `Router#match` and `Route#match` are now pure functions that return
  an array of routes that match the URL path.
  
  For modules using this private API that need to determine if a method and path
  match a route, `route.methods` must be checked against the routes returned from
  `router.match()`:
  
  ```javascript
  var matchedRoute = router.match(path).filter(function (route) {
    return ~route.methods.indexOf(method);
  }).shift();
  ```
  ...

function koa-router.layer.prototype.param (param, fn)

• description and source-code

  param = function (param, fn) {
    var stack = this.stack;
    var params = this.paramNames;
    var middleware = function (ctx, next) {
      return fn.call(this, ctx.params[param], ctx, next);
    };
    middleware.param = param;
  
    var names = params.map(function (p) {
      return p.name;
    });
  
    var x = names.indexOf(param);
    if (x > -1) {
      // iterate through the stack, to figure out where to place the handler fn
      stack.some(function (fn, i) {
        // param handlers are always first, so when we find an fn w/o a param property, stop here
        // if the param handler at this part of the stack comes after the one we are adding, stop here
        if (!fn.param || names.indexOf(fn.param) > x) {
          // inject this param handler right before the current item
          stack.splice(i, 0, middleware);
          return true; // then break the loop
        }
      });
    }
  
    return this;
  }

• example usage

  ...
        * [.routes](#module_koa-router--Router+routes) ⇒ <code>function</code>
        * [.use([path], middleware, [...])](#module_koa-router--Router+use) ⇒ <code>Router</code>
        * [.prefix(prefix)](#module_koa-router--Router+prefix) ⇒ <code>Router</code>
        * [.allowedMethods([options])](#module_koa-router--Router+allowedMethods) ⇒ <code>function</code>
        * [.redirect(source, destination, code)](#module_koa-router--Router+redirect) ⇒ <code>Router</code>
        * [.route(name)](#module_koa-router--Router+route) ⇒ <code>Layer</code> &#124; <code>false
  </code>
        * [.url(name, params)](#module_koa-router--Router+url) ⇒ <code>String</code> &#124; <code>
  ;Error</code>
        * [.param(param, middleware)](#module_koa-router--Router+param) ⇒ <code>
  ;Router</code>
      * _static_
        * [.url(path, params)](#module_koa-router--Router.url) ⇒ <code>String</code>
  
  <a name="exp_module_koa-router--Router"></a>
  ### Router ⏏
  **Kind**: Exported class
  <a name="new_module_koa-router--Router_new"></a>
  ...

function koa-router.layer.prototype.params (path, captures, existingParams)

• description and source-code

  params = function (path, captures, existingParams) {
    var params = existingParams || {};
  
    for (var len = captures.length, i=0; i<len; i++) {
      if (this.paramNames[i]) {
        var c = captures[i];
        params[this.paramNames[i].name] = c ? safeDecodeURIComponent(c) : c;
      }
    }
  
    return params;
  }

• example usage

  ...
  
    var mostSpecificPath = matched.pathAndMethod[matched.pathAndMethod.length - 1].path;
    ctx._matchedRoute = mostSpecificPath;
  
    layerChain = matched.pathAndMethod.reduce(function(memo, layer) {
      memo.push(function(ctx, next) {
        ctx.captures = layer.captures(path, ctx.captures);
        ctx.params = layer.params(path, ctx.captures, ctx.params);
        return next();
      });
      return memo.concat(layer.stack);
    }, []);
  
    return compose(layerChain)(ctx, next);
  };
  ...

function koa-router.layer.prototype.setPrefix (prefix)

• description and source-code

  setPrefix = function (prefix) {
    if (this.path) {
      this.path = prefix + this.path;
      this.paramNames = [];
      this.regexp = pathToRegExp(this.path, this.paramNames, this.opts);
    }
  
    return this;
  }

• example usage

  ...
    if (hasPath) {
      path = middleware.shift();
    }
  
    middleware.forEach(function (m) {
      if (m.router) {
  m.router.stack.forEach(function (nestedLayer) {
    if (path) nestedLayer.setPrefix(path);
    if (router.opts.prefix) nestedLayer.setPrefix(router.opts.prefix);
    router.stack.push(nestedLayer);
  });
  
  if (router.params) {
    Object.keys(router.params).forEach(function (key) {
      m.router.param(key, router.params[key]);
  ...

function koa-router.layer.prototype.url (params)

• description and source-code

  url = function (params) {
    var args = params;
    var url = this.path;
    var toPath = pathToRegExp.compile(url);
  
    // argument is of form { key: val }
    if (typeof params != 'object') {
      args = Array.prototype.slice.call(arguments);
    }
  
    if (args instanceof Array) {
      var tokens = pathToRegExp.parse(url);
      var replace = {};
      for (var len = tokens.length, i=0, j=0; i<len; i++) {
        if (tokens[i].name) replace[tokens[i].name] = args[j++];
      }
      return toPath(replace);
    }
    else {
      return toPath(params);
    }
  }

• example usage

  ...
  ## 5.4.0
  
  - Expose matched route at `ctx._matchedRoute`.
  
  ## 5.3.0
  
  - Register multiple routes with array of paths [#203](https://github.com/alexmingoia/koa-router/issue/143).
  - Improved router.url() [#143](https://github.com/alexmingoia/koa-router/pull/143)
  - Adds support for named routes and regular expressions
    [#152](https://github.com/alexmingoia/koa-router/pull/152)
  - Add support for custom throw functions for 405 and 501 responses [#206](https://github.com/alexmingoia/koa-router/pull/206)
  
  ## 5.2.3
  
  - Fix for middleware running twice when nesting routes [#184](https://github.com/alexmingoia/koa-router/issues/184)
  ...