如何在手把中的mongo
subdocument
中添加所需字段?
例如,如果我的数组是:
var fruits=[{ _id: 1, fruit: 'banana', number: 1 },{ _id: 2, fruit: 'Apple', number: 1 }]
我想通过做这样的事情把所有的numbers
加在一起:
app.engine('handlebars', exphbs({
defaultLayout: 'mainlayout',
helpers: {
addfruit: function(fruit){
var addfruit="";
for (each fruit){
addfruit+=fruit.number;
return addfruit;
}
},
};
我的html:
<div><p>You have {{addfruit fruits}} in your fridge</p></div>
非常感谢您的帮助!
在助手函数中,使用JavaScriptreduce()
方法对fruits
数组中对象的number
字段求和,如下所示就足够了:
app.engine('handlebars', exphbs({
defaultLayout: 'mainlayout',
helpers: {
getTotal: function (fruits){
var total = fruits.reduce(function (a, b) { return a + b.number; }, 0);
return total;
}
}
});
然后在你的html:中
<div><p>You have {{getTotal fruits}} in your fridge</p></div>
感谢您的指导。以下是我最终所做的:
getTotal: function(fruit){
var myfruit = fruit.map(function(item) {
return item.length;
});
var total=myfruit.reduce(function(prev,curr){
return prev+curr},0);
return total;
}