流星-从方法返回集合对象

Question

I'm trying to return a collection object from a Meteor method based on a set session.

Here's the method call:

Template.batches.search = function () {
    if (typeof Session.get('search-parameters') != 'undefined') {

        var searchParameters = Session.get('search-parameters');

        return Meteor.call('search', searchParameters, function(error , result){
            if (error) {
                console.log(error.reason);
            } else{
                return result;
            }
        });
    }
}

Here's the method being calledL

Meteor.methods({
    search: function (session) {
        return Batches.find({event: { $regex: session}});
    }
});

I've read that a method cannot return a collection object and to use fetch() instead. This returns an array, however, I'm unable to iterate over the array like a colleciton object to return the results. Please advise.

Answer 1

Template helpers need to be synchronous. There are a few ways to solve this, but here's an example:

Template.batches.created = function() {
  // this will be cleaned up for you when the template is destroyed
  this.autorun(function() {
    var search = Session.get('search-parameters');
    Meteor.subscribe('batchesForSearch', search);
  });
};

Template.batches.helpers({
  search: function() {
    var search = Session.get('search-parameters');
    return Batches.find({event: {$regex: search}});
  }
});

In the batches template, create an autorun which subscribes to batchesForSearch whenever the session changes. Once the documents arrive on the client, they will be made available to your template via the search helper.

The batchesForSearch publish function could look something like this:

Meteor.publish('batchesForSearch', function(search) {
  check(search, String);

  if (_.isEmpty(search)) {
    // make sure we do not publish the entire collection if search is empty 
    return this.ready();
  } else {
    return Batches.find({event: {$regex: search}});
  }
});

Note that we are careful to avoid publishing the entire collection in case the search is empty.