Internet-programming_PIbd-2.../Library/node_modules/express/lib/view.js

183 lines
3.2 KiB
JavaScript

/*!
* express
* Copyright(c) 2009-2013 TJ Holowaychuk
* Copyright(c) 2013 Roman Shtylman
* Copyright(c) 2014-2015 Douglas Christopher Wilson
* MIT Licensed
*/
'use strict';
/**
* Module dependencies.
* @private
*/
var debug = require('debug')('express:view');
var path = require('path');
var fs = require('fs');
/**
* Module variables.
* @private
*/
var dirname = path.dirname;
var basename = path.basename;
var extname = path.extname;
var join = path.join;
var resolve = path.resolve;
/**
* Module exports.
* @public
*/
module.exports = View;
/**
* Initialize a new `View` with the given `name`.
*
* Options:
*
* - `defaultEngine` the default template engine name
* - `engines` template engine require() cache
* - `root` root path for view lookup
*
* @param {string} name
* @param {object} options
* @public
*/
function View(name, options) {
var opts = options || {};
this.defaultEngine = opts.defaultEngine;
this.ext = extname(name);
this.name = name;
this.root = opts.root;
if (!this.ext && !this.defaultEngine) {
throw new Error('No default engine was specified and no extension was provided.');
}
var fileName = name;
if (!this.ext) {
// get extension from default engine name
this.ext = this.defaultEngine[0] !== '.'
? '.' + this.defaultEngine
: this.defaultEngine;
fileName += this.ext;
}
if (!opts.engines[this.ext]) {
// load engine
var mod = this.ext.slice(1)
debug('require "%s"', mod)
// default engine export
var fn = require(mod).__express
if (typeof fn !== 'function') {
throw new Error('Module "' + mod + '" does not provide a view engine.')
}
opts.engines[this.ext] = fn
}
// store loaded engine
this.engine = opts.engines[this.ext];
// lookup path
this.path = this.lookup(fileName);
}
/**
* Lookup view by the given `name`
*
* @param {string} name
* @private
*/
View.prototype.lookup = function lookup(name) {
var path;
var roots = [].concat(this.root);
debug('lookup "%s"', name);
for (var i = 0; i < roots.length && !path; i++) {
var root = roots[i];
// resolve the path
var loc = resolve(root, name);
var dir = dirname(loc);
var file = basename(loc);
// resolve the file
path = this.resolve(dir, file);
}
return path;
};
/**
* Render with the given options.
*
* @param {object} options
* @param {function} callback
* @private
*/
View.prototype.render = function render(options, callback) {
debug('render "%s"', this.path);
this.engine(this.path, options, callback);
};
/**
* Resolve the file within the given directory.
*
* @param {string} dir
* @param {string} file
* @private
*/
View.prototype.resolve = function resolve(dir, file) {
var ext = this.ext;
// <path>.<ext>
var path = join(dir, file);
var stat = tryStat(path);
if (stat && stat.isFile()) {
return path;
}
// <path>/index.<ext>
path = join(dir, basename(file, ext), 'index' + ext);
stat = tryStat(path);
if (stat && stat.isFile()) {
return path;
}
};
/**
* Return a stat, maybe.
*
* @param {string} path
* @return {fs.Stats}
* @private
*/
function tryStat(path) {
debug('stat "%s"', path);
try {
return fs.statSync(path);
} catch (e) {
return undefined;
}
}