ddms是基于express的一个表单管理系统，今天抽时间看了下它的代码，其实算不上源码学习，只是对它其中一些小的开发技巧做一些记录，希望以后在项目开发中能够实践下。
- 数据层封装
- 模块只对外暴露model，由业务层完成具体数据操作；
- 利用mongoose的schema的static属性，扩展常用、基础的操作
var form = new Schema({
user: {type: ObjectId, ref: 'User'},
project: {type: ObjectId, ref: 'Project'},
sid: {type: String, unique: true,'default': shortid.generate },
title: {
type: String,
required: true,
default: 'New Form'
},
desc: String,
createDateTime: {
type: Date,
default: Date.now
},
updateDateTime: {
type: Date,
default: Date.now
},
schemata: Mixed
});
form.static({
list: function (callback) {
return this.find()
.populate('user',{_id: 1,name: 1,email: 1,role: 1})
.populate('project',{_id: 1,name: 1,desc: 1})
.sort({_id: -1})
.exec(callback)
},
listByProjectId: function (projectid,callback) {
return this.find({project: projectid})
.populate('user',{_id: 1,name: 1,email: 1,role: 1})
.populate('project',{_id: 1,name: 1,desc: 1})
.sort({_id: -1})
.exec(callback);
}
});
module.exports = mongoose.model('Form', form);
- 充分利用schema type特性
- 充分利用schema type的例如getter\setter\validate等 参考：http://mongoosejs.com/docs/2.7.x/docs/schematypes.html。可以将原本业务层的很多处理直接交给mongodb.
var userSchema = new Schema({
email: {
type: String,
required: true, //需要校验
//给字段存储前线全部小写处理
set: function (value) {
return value.trim().toLowerCase()
},
//校验的方法
validate: [
function (email) {
return (email.match(/[a-z0-9!#$%&'*+\/=?^_`{|}~-]+(?:\.[a-z0-9!#$%&'*+\/=?^_`{|}~-]+)*@(?:[a-z0-9](?:[a-z0-9-]*[a-z0-9])?\.)+[a-z0-9](?:[a-z0-9-]*[a-z0-9])?/i) != null)
},
'Invalid email'
]
},
//。。。。
twitter: Mixed
});
- 利用ref来实现join，可以存在多个，如下：
var form = new Schema({
user: {type: ObjectId, ref: 'User'},
project: {type: ObjectId, ref: 'Project'},
sid: {type: String, unique: true,'default': shortid.generate },
form.static({
list: function (callback) {
return this.find()
.populate('user',{_id: 1,name: 1,email: 1,role: 1})
.populate('project',{_id: 1,name: 1,desc: 1})
.sort({_id: -1})
.exec(callback)
},
listByProjectId: function (projectid,callback) {
return this.find({project: projectid})
.populate('user',{_id: 1,name: 1,email: 1,role: 1})
.populate('project',{_id: 1,name: 1,desc: 1})
.sort({_id: -1})
.exec(callback);
}
});
- 充分利用app.use
- app.use在express中类似servlet里的filter，属于一种过滤器，它会在每个http请求中被调用
- ddms通过app.use向req对象中添加model
//app.js中
app.use(function (req, res, next) {
if (!models.User) return next(new Error("No models."));
req.models = models;
return next();
}); //route.js中
exports.showListByProjectId = function (req, res, next) {
var pid = req.params.projectid;
var pp = Promise.resolve( req.models.Project.findOne({_id: pid}) );
var fp = Promise.resolve( req.models.Form.listByProjectId(pid) ); Promise.all([pp,fp])
.then(function(docs){
res.render('forms/list', {project: docs[0],forms: docs[1]});
}).catch(function (error) {
return next(error);
});
};
- 采用bluebird的promise库做同步
之前一直用async，看了下promise，感觉非常清爽，同上例代码
- 利用app.get的多callback实现中间件的效果，如下：
app.get('/formdatas/:formid', authorize.editor, routes.formData.showList);
app.get('/formdatas/create/:formid', authorize.editor, routes.formData.showCreateData);
app.post('/formdatas/create/:formid', writeLog, authorize.editor, routes.formData.createData);
app.get('/formdatas/update/:id', authorize.editor, routes.formData.showUpdateData);
app.post('/formdatas/update/:id', writeLog, authorize.editor, routes.formData.updateData);
app.get('/formdatas/delete/:id', writeLog, authorize.editor, routes.formData.deleteData);
app.get('/formdatas/csv/:formid', writeLog, authorize.editor, routes.formData.getCSV);