CODEWITHSUNDEEP
meteor
greymatter
greymatter

Reputation: 990

Summing a column in a table in Meteor

If I create a table in a Template, is there a way to add a row of "reactive totals" at the bottom of the table using Meteor? Or do I have to write the code to sum the columns, the same way I would in ordinary JavaScript?

For example, given the table...

State   Sales
NY      1234
FL       670
TX      2306
Total   4210

Can I use some reactive technique to calculate and keep the Total cell showing 4210 up-to-date as other cells change?

Upvotes: 1

Views: 669

Answers (4)

dpatte
dpatte

Reputation: 69

I had the same issue, and have found the following solution for both columns and rows of a table

In Meteor, how can i do a sum of some computed fields in a table?

Upvotes: 0

Peppe L-G
Peppe L-G

Reputation: 8345

I've created the package peppelg:mongo-sum. With it, MyCollection.find().sum('field') will return the sum of all the values in the field 'field'.

Upvotes: 0

rivarolle
rivarolle

Reputation: 1538

Another way to do this is to use MongoDB $sum aggregator

Taking Erik Johnson's example, you need to do this:

// HTML

<div id="allSales">
  <h2><span>Total sales: </span>{{allSales}}</h2>
</div>

// JS

Template.templatename.helpers({    
  allSales: function() {
    var allSales =  allStates.aggregate( [ { $group: { _id: null, total: { $sum: "$sales" } } } ]);
    return allSales.total;

  },
});

Upvotes: 2

Erik Johnson
Erik Johnson

Reputation: 55

This is how I've done it - I'm sure there's probably an easier way, but I'm still a beginner at Meteor:

// HTML

<div id="allSales">
  <h2><span>Total sales: </span>{{allSales}}</h2>
</div>

// JS

Template.templatename.helpers({    
  allSales: function() {
    var allStates = Statescollection.find();
    var mappedItems = allStates.map((function(allStates) {return allStates.sales;}));
    var allSales = _.reduce(mappedItems, function(memo, num){ return memo + num; }, 0);
    return allSales;
  },
});

Upvotes: 0

Related Questions