How to format timestamps in batch in nodejs-CodePudding

I use koajs to wrote a webapp and I'm having a little trouble with the timestamp format in the database, there are a lot of records and each record is formatted like this.

{
    "_id": {
        "$oid": "61df7c96d649ac83eefa36d3"
    },
    "key": 1286756906,
    "status": 1,
    "name": "bill",
    "starttime": 1642068153784,
    "endtime": 1673604153784
}

I need to show starttime and endtime on the front-end in format like 2022-01-03 10:10:10.

Where should I put the timestamp formatting process on? The front-end or the back-end?
My current solution is the back-end, like following

list.js

.get("/list", async (ctx) => {
   let allrecords = await db.myrecords.find();
   await ctx.render("list", {
       allrecords: allrecords.map(d => { d.endtime = new Date(d.endtime).getFullYear()   "-"   (new Date(d.endtime).getMonth() 1 < 10? '0'  (new Date(d.endtime).getMonth() 1):(new Date(d.endtime).getMonth() 1))   "-"   new Date(d.endtime).getDate()   " "   new Date(d.endtime).getHours()   ":"   (new Date(d.endtime).getMinutes()< 10  ? '0'   new Date(d.endtime).getMinutes():new Date(d.endtime).getMinutes()); return d}).map(d => { d.starttime = new Date(d.starttime).getFullYear()   "-"   (new Date(d.starttime).getMonth() 1 < 10? '0'  (new Date(d.starttime).getMonth() 1):(new Date(d.starttime).getMonth() 1))   "-"   new Date(d.starttime).getDate()   " "   new Date(d.starttime).getHours()   ":"   (new Date(d.starttime).getMinutes()< 10  ? '0'   new Date(d.starttime).getMinutes():new Date(d.starttime).getMinutes()); return d})
   });
})

list.ejs

<% allrecords.forEach(function(item, i){%>
 <div >
 <div>start: <%=item.starttime%></div>
 <div>end: <%=item.endtime%></div>
 </div>
<%})%>

I find this solution too inefficient, is there any other efficient solution?

Thank you.

CodePudding user response：

Doing it on server side is fine, if you only need those time values as strings on client side. For the mapping I would do:

.get("/list", async (ctx) => {
    let allrecords = await db.myrecords.find();
    await ctx.render("list", {
        allrecords: allrecords.map(d => { 
            d.endtime = new Date(d.endtime).toISOString().
                                .replace('T', ' ').substr(0, 19);
            d.starttime = new Date(d.starttime).toISOString().
                                .replace('T', ' ').substr(0, 19);
            return d
        });
    });
})

Then you are creating each of your dates only one single time.