问题描述
我建立使用MongoDB的,棱角分明,前preSS的应用程序,和节点(MEAN堆栈)。
I am building an application using MongoDB, Angular, Express, and Node (MEAN stack).
我用MEAN.JS发电机脚手架我的申请。
I used the MEAN.JS generator to scaffold my application.
我将使用模块的文章作为参考。
I will use the articles module as a reference.
假如我有7000条记录在我的文章集合,每条记录都有一个与之相关联的日期。这是一种低效每次都记录7000加载到内存我加载页面在表中查看记录,我看到的,因为它可怕的性能损失。出于这个原因,我只想加载记录与(1个月前)范围内的日期(1从现在起一年),并在表中显示出来。我目前与以下做到这一点:
Suppose I have 7000 records in my articles collection, and each record has a date associated with it. It is inefficient to load all 7000 records into memory every time I load the page to view the records in a table and I am seeing terrible performance losses because of it. For this reason, I would only like to load records with a date in the range of (1 Month Ago) to (1 Year From Now) and display them in the table. I can currently do this with the following:
在我articles.client.controller.js:
In my articles.client.controller.js:
$scope.find = function() {
$articles = Articles.query();
};
...在我的articles.server.controller.js:
...and in my articles.server.controller.js:
var now = new Date();
var aYearFromNow = new Date(now.getTime() + 86400000*365); //add a year
var aMonthAgo = new Date(now.getTime() - 86400000*30); //subtract roughly a month
exports.list = function(req, res) { Article.find().where('date').lt(aYearFromNow).gt(aMonthAgo).sort('-created').populate('user', 'displayName').exec(function(err, articles) {
if (err) {
return res.send(400, {
message: getErrorMessage(err)
});
} else {
res.jsonp(articles);
}
});
};
的问题是,这不是一个做事的动态的方式。换句话说,我希望用户能够指定前进,他们希望回来多远多远看。
The problem is that this is not a dynamic way of doing things. In other words, I want the user to be able to specify how far back and how far forward they want to see.
如何绑定变量(例如'aYearFromNow'和'aMonthAgo')在我的客户认为这将改变我的服务器控制器的查询参数?
推荐答案
这可能不是最彻底的方法,但您可以创建一个新的服务(或编辑当前有几个参数来工作):
It's probably not the cleanest way, but you can create a new service (or edit the current one to work with several parameters):
.factory('ArticlesService2', ['$resource',
function($resource) {
return $resource('articles/:param1/:param2', {
param1: '',
param2: ''
}, {
update: {
method: 'PUT'
}
});
}
]);
然后把它在你的控制器:
Then call it in your controller :
$scope.findWithParams = function() {
$scope.article = ArticlesService2.query({
param1: $scope.aYearFromNow,
param2: $scope.aMonthAgo
});
};
在后端,你需要prepare路线:
On the back-end, you'll need to prepare a route :
app.route('/articles/:param1/:param2')
.get(articles.listWithParams)
添加一个函数来后端控制器:
Add a function to your back-end controller :
exports.listWithParams = function(req, res) {
Article.find()
.where('date')
.lt(req.params.param1)
.gt(req.params.param2)
.sort('-created').populate('user', 'displayName')
.exec(function(err, articles) {
if (err) {
return res.send(400, {
message: getErrorMessage(err)
});
} else {
res.jsonp(articles);
}
});
};
应该工作,没有虽然进行了测试。
Should work, haven't tested it though.
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