express 版本更新后遇到的问题
flash()
首先发一个
原先的express 2.X中提供的API flash();
我找到一个关于修改的说明 req.flash() (just use sessions: req.session.messages = [‘foo’] or similar)
请问这个API原先的用途是什么?
2 回复
/**
* Queue flash `msg` of the given `type`.
*
* Examples:
*
* req.flash('info', 'email sent');
* req.flash('error', 'email delivery failed');
* req.flash('info', 'email re-sent');
* // => 2
*
* req.flash('info');
* // => ['email sent', 'email re-sent']
*
* req.flash('info');
* // => []
*
* req.flash();
* // => { error: ['email delivery failed'], info: [] }
*
* Formatting:
*
* Flash notifications also support arbitrary formatting support.
* For example you may pass variable arguments to `req.flash()`
* and use the %s specifier to be replaced by the associated argument:
*
* req.flash('info', 'email has been sent to %s.', userName);
*
* To add custom formatters use the `exports.flashFormatters` object.
*
* @param {String} type
* @param {String} msg
* @return {Array|Object|Number}
* @api public
*/
req.flash = function(type, msg){
if (this.session === undefined) throw Error('req.flash() requires sessions');
var msgs = this.session.flash = this.session.flash || {};
if (type && msg) {
var i = 2
, args = arguments
, formatters = this.app.flashFormatters || {};
formatters.__proto__ = flashFormatters;
msg = utils.miniMarkdown(msg);
msg = msg.replace(/%([a-zA-Z])/g, function(_, format){
var formatter = formatters[format];
if (formatter) return formatter(utils.escape(args[i++]));
});
return (msgs[type] = msgs[type] || []).push(msg);
} else if (type) {
var arr = msgs[type];
delete msgs[type];
return arr || [];
} else {
this.session.flash = {};
return msgs;
}
};
自己猜
Migrating from 2.x to 3.x
req.flash() (just use sessions: req.session.messages = [‘foo’] or similar) connect-flash can be used as middleware to provide req.flash()
需要安装 npm install connect-flash 在app.js中加入 var flash = require(‘connect-flash’); app.use(flash());
这样就能继续用 req.flash()