whistle.vase/lib/server.js

用于mock数据的whistle插件

var express = require('express');
var fs = require('fs');
var app = express();
var bodyParser = require('body-parser');
var dataMgr = require('./data-mgr');
var engine = require('./engine');
var parseScript = require('./script-parser');
var util = require('./util');
var RULE_VALUE_HEADER, SSL_FLAG_HEADER;
var TPL_NAME = 'vaseId';
var CMD_RE = /^([\w-]+):/;

function getVaseId(req) {
  if (RULE_VALUE_HEADER) {
    var vaseId = req.headers[RULE_VALUE_HEADER];
    return vaseId && decodeURIComponent(vaseId + '');
  }
  return req.query[TPL_NAME] + '';
}

//判断是否是https请求
function isHttps(req) {
  return !!req.headers[SSL_FLAG_HEADER];
}

function renderTpl(vaseId, tpl, req, callback) {
  var headers = {'content-type': util.getMime(vaseId) + '; charset=utf8'};
  req.isHttps = isHttps(req);
  if (tpl.type == 'script') {
    parseScript(tpl.value, req, function(err, out) {
      if (err) {
        callback(err, 500);
      } else {
        out.headers = util.merge(headers, out.headers);
        callback(null, out);
      }
    });
  } else {
    engine.render(tpl.value, req.locals, tpl.type, function(err, body) {
      if (err) {
        callback(err, 500);
      } else {
        callback(null, {
          statusCode: 200, 
          headers: headers, 
          body: util.stringify(body)
        });
      }
    });
  }
}

function render(req, callback) {
  var vaseId = getVaseId(req);
  if (!vaseId) {
    return callback(new Error('Not found'), 404);
  }
  var tpl = dataMgr.getTpl(vaseId);
  if (tpl) {
    return renderTpl(vaseId, tpl, req, callback);
  }
  var type;
  if (CMD_RE.test(vaseId)) {
    type = RegExp.$1;
    if (engine.existsEngine(type)) {
      vaseId = vaseId.substring(type.length + 1);
    }
  }
  if (!vaseId) {
    return callback(new Error('Not found'), 404);
  }
  fs.readFile(vaseId, { encoding: 'utf8' }, function(err, text) {
    if (err) {
      return callback(err, err.code === 'ENOENT' ? 404 : 500);
    }
    renderTpl(vaseId, { value: text, type: type }, req, callback);
  });
}

function responseError(res, err, statusCode) {
  res.writeHead(statusCode, {
    'content-type': 'text/plain; charset=utf8'
  });
  res.end(err.stack);
}

app.use(function(req, res, next) {
  req.on('error', util.noop);
  res.on('error', util.noop);
  next();
});
app.use(bodyParser.urlencoded({ extended: true, limit: '3mb'}));
app.use(bodyParser.json());
app.use(function(req, res, next) {
  util.drain(req, next);
});

app.use(function(req, res) {
  req.locals = util.merge({}, req.query, req.body);
  render(req, function(err, out) {
    if (err) {
      responseError(res, err, out);
    }else {
      res.writeHead(out.statusCode, out.headers);
      out.pipe ? out.pipe(res) : res.end(out.body);
    }
  });
});

module.exports = function startServer(server, options) {
  if (options) {
    RULE_VALUE_HEADER = options.RULE_VALUE_HEADER;
    SSL_FLAG_HEADER = options.SSL_FLAG_HEADER;
  }
  server.on('request', app);
};