routing functions from dispatch

pico.php

<?php
# @author Jesus A. Domingo
# @license MIT <http://noodlehaus.mit-license.org>

namespace noodlehaus\pico;

# returns the value for an http request header
function request_header($name) {

  $headers = &$GLOBALS['app/state']['request_headers'];

  # first call, prime it
  if (!count($headers)) {

    # if we're not in CLI, use it
    if (function_exists('getallheaders')) {
      $headers = array_change_key_case(getallheaders());
    } else {

      # manual header extraction (CLI + test)
      $special = array('CONTENT_LENGTH', 'CONTENT_MD5', 'CONTENT_TYPE');

      # get the rest of the headers out
      foreach ($_SERVER as $name => $data) {
        if (0 === strpos($name, 'HTTP_')) {
          $name = strtolower(str_replace('_', '-', substr($name, 5)));
          $headers[$name] = $data;
        } else if (in_array($name, $special)) {
          $name = strtolower(str_replace('_', '-', $name));
          $headers[$name] = $data;
        }
      }
    }
  }

  # normalize the input then try to fetch
  $name = trim(strtolower($name));

  return isset($headers[$name]) ? $headers[$name] : null;
}

# function for mapping actions to routes
function map() {

  $args = func_get_args();
  $data = &$GLOBALS['app/state']['routes'];

  # try to figure out how we were called
  switch (count($args)) {

    # (method, path, handler)
    case 3:
      foreach ((array) $args[0] as $verb) {
        $data['explicit'][strtoupper($verb)][] = array(
          '/'.trim($args[1], '/'),
          $args[2]
        );
      }
      break;

    # (path, handler)
    case 2:
      foreach ((array) $args[0] as $path) {
        $data['any'][] = array('/'.trim($path, '/'), $args[1]);
      }
      break;

    # any method and any path (just one for this, replace ref)
    case 1:
      $data['all'] = $args[0];
      break;

    # everything else
    default:
      throw new BadFunctionCallException(
        'Invalid number of arguments.',
        500
      );
  }
}

# hooks actions to route symbols
function hook($name, $func) {
  $GLOBALS['app/state']['routes']['hooks'][$name] = $func;
}

# dispatches the current request against our handlers/actions
function run() {

  $args = func_get_args();
  $data = &$GLOBALS['app/state']['routes'];

  $path = parse_url($_SERVER['REQUEST_URI'], PHP_URL_PATH);
  $path = trim($path, '/');

  $path = trim($path, '/');
  $verb = strtoupper($_SERVER['REQUEST_METHOD']);

  # for POST requests, check for method override header or _method
  if ($verb == 'POST') {
    if (isset($_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE'])) {
      $verb = strtoupper($_SERVER['HTTP_X_HTTP_METHOD_OVERRIDE']);
    } else {
      $verb = isset($_POST['_method']) ? strtoupper($_POST['_method']) : $verb;
    }
  }

  # set any mapping as base, then append exp_mapping if any
  $maps = $data['any'];
  if (isset($data['explicit'][$verb])) {
    $maps = array_merge($data['explicit'][$verb], $maps);
  }

  $rexp = null;
  $func = null;
  $vals = null;

  # try to see if we have any matching route
  foreach ($maps as $temp) {

    list($rexp, $call) = $temp;

    $rexp = trim($rexp, '/');
    $rexp = preg_replace('@\{(\w+)\}@', '(?<\1>[^/]+)', $rexp);

    if (!preg_match('@^'.$rexp.'$@', $path, $vals)) {
      continue;
    }

    $func = $call;
    break;
  }

  # valid handler, try to parse out route symbol values
  if ($func && is_callable($func)) {

    # remove top group from vals
    array_shift($vals);

    # extract route symbols and run the hook()s
    if ($vals) {

      # extract any route symbol values
      $toks = array_filter(array_keys($vals), 'is_string');
      $vals = array_map('urldecode', array_intersect_key(
        $vals,
        array_flip($toks)
      ));

      # if we have symbol hooks, run them
      if (count($data['hooks'])) {

        foreach ($vals as $key => $val) {

          if (!isset($data['hooks'][$key])) {
            continue;
          }

          $hook = $data['hooks'][$key];

          $vals[$key] = call_user_func_array(
            $hook,
            array_merge((array) $val, $args)
          );
        }
      }

      # insert symbol values before dispatch() args
      array_unshift($args, $vals);
    }

  } else {

    # no matching handler, try to use 'all', or 404
    if (is_callable($data['all'])) {
      $func = $data['all'];
    } else {
      $func = function () {
        \header("{$_SERVER['SERVER_PROTOCOL']} 404 Not found", true, 404);
        echo "Not found\n";
        exit;
      };
    }

  }

  return call_user_func_array($func, $args);
}

# state (routes, handlers, etc)
$GLOBALS['app/state'] = array(
  'stash' => array(),
  'request_headers' => array(),
  'routes' => array(
    'all' => null,
    'any' => array(),
    'hooks' => array(),
    'explicit' => array(),
    'errors' => array()
  )
);