在MongoDB中排序

Question

I don't have any idea how to get ordered list from Mongo data. I need to return .find() result from mongo collection, in kind of this way:

For example! At first, I have One collection for cars with 10 documents:

//doc structure:
{
  _id: 10,
  name: name,
  type: [suv, sedan, sport],
  driver: [object Driver]
  pubDate: new Date()
}

And for second, I have Two col. with two types of drivers:

//doc structure:
{
  _id: 20,
  name: name,
  type: stupid 'or' clever
}

And now I want to return list in this order, for example:

1. name: Ford Focus, driver: {name: Nick, type: clever }, pubDate: 20:00 ;
2. name: Nissan GTR, driver: {name: Andrew, type: clever }, pubDate: 19:00 ;
3. name: Jaguar xKR, driver: {name: John, type: clever }, pubDate: 15:00 ;
4. name: Honda Accord, driver: {name: Petr, type: clever }, pubDate: 14:00
5. name: Nissan GTR, driver: {name: Andrew, type: clever }, pubDate: 13:00 ;
6. name: Tesla, driver: {name: Jorge, type: stupid }, pubDate: 20:00 ;
7. name: Audi q7, driver: {name: Peggy, type: stupid }, pubDate: 19:00 ;
8. name: BMW 325, driver: {name: Minnie, type: stupid }, pubDate: 18:00 ;
9. name: CADILLAC, driver: {name: Timothy, type: stupid }, pubDate: 16:00 ;
10. name: SAAB, driver: {name: Julia, type: stupid }, pubDate: 15:00 ;

Nowadays, I have one solution, but It's not correct, and it's not work with infinite scroll. Meteor example:

// declare collections
Cars = Mongo.collection('cars', {
  name: name,
  type: [suv, sedan, sport],
  driver: [object Driver]
  pubDate: new Date()
}); 

Driver = Mongo.collection('cars', {
  name: name,
  lastName: lastName,
  type: stupid // or clever
}); 



// declare helpers for client:
Template.carList.helpers({
  'clever': function() {
     return Cars.find({driver.type: 'clever'}, {sort: {pubDate: -1});
     // returned only clever
   },
  'stupid': function() {
     return Cars.find({driver.type: 'stupid'}, {sort: {pubDate: -1});
     // returned only stupid
  }
 }):

And HTML with blaze:

<template name='carList'>
     ...
      {{#each clever}}
        ...
      {{/each}}
      {{#each stupid}}
        ...
      {{/each}}
</template>

It's work, but it's not flexible way, because if i need to set some new parameters for sorting, I'll get many problems with it. And this example with one Drivers collection, but what if types of users will be in separate collections, like Stupid & Clever?

I think that there must be a more elegant way for aggregate this.

Which? Thank you!

Answer 1

How about passing the sort list to the helper and using that to build the sort?

Super-simple off-the-top-of-my-head example:

Template.carList.helpers({
  clever: function(sortField) {
    options = {};
    if (sortField) {
      options.sort = {sortField: -1};
    }
    return Cars.find({driver.type: 'clever'}, options);
  }
});

And in the HTML:

<template name='carList'>
     ...
      {{#each clever "name"}}
        ...
      {{/each}}
      {{#each stupid}}
        ...
      {{/each}}
</template>

You could get a little more complex and pass in key/value pairs, which Spacebars supports via Spacebars.kw (read here and here ). You would essentially pass in the arguments like name=-1 pubDate=1 , then in your helper parse out the resulting hash that is passed in and add them to your options. You may need to tinker with how it works, but that should get you started at least.