Meteor - How To Extract Key Name From Collection? - meteor

Question

I have the following in my initialize file to get the values loaded in the database on startup:
Meteor.startup(function() {
if(typeof Person.findOne() === 'undefined') {
Person.insert({
name: "",
gender: ["male", "female", "prefer not to say"],
age: 0
});
}
});
And then in the server/abc.js I have:
Meteor.methods({
checkPerson: function (input) {
for (var key in Person) {
if (input === key) {
...
}
}
}
});
This meteor method checkPerson is called in the client side with a string value being passed as its only argument(input).
I want to check this 'input' string value against the name of the key in the Person Collection.
Person has a key called 'gender'. So for instance, if the 'input' holds the string value 'gender' then the if statement should be true but in my case it comes as false and hence the code inside the if statement is never executed.
Any help/guidance with this will be appreciated.
UPDATE
I searched on mongodb documentation and found here: http://docs.mongodb.org/manual/reference/operator/query/exists/ and also using some help from this thread: (using $exists in Mongo with dynamic key names and the native driver for node)
that I could do something like this:
var checkThis = {};
checkThis[input] = { $exists : true };
var p = Person.findOne(checkThis);
So if it finds one then 'p' holds the record or else it will be undefined. But still the above code does not work.
If I were to put directly:
var p = Person.find({gender: {$exists: true} });
then it works.
So I need assistance in getting the code to work with the variable 'input'.

Answer 1

Mongo is a schemaless database - you can insert any document structure you like into a collection and the data store won't complain. Therefore Person won't be able to indicate which fields conform to the pattern.
The most common way people deal with this problem is to use a package which provides a schema layer on top of mongo. With meteor, a popular choice is SimpleSchema, and its related package AutoForm. SimpleSchema allows you to define which fields should be allowed into a collection, and AutoForm gives you a set of helpers to enforce them in your UI.
If, instead, you prefer not to use a package you could do something like the following:
person.js
var REQUIRED_FIELDS = {
name: String,
gender: ['male', 'female', 'prefer not to say'],
age: Number
};
Person = new Meteor.Collection('person');
Person.isValid = function(person) {
try {
check(person, REQUIRED_FIELDS);
return true;
} catch (_error) {
return false;
}
};
Meteor.methods({
'person.insert': function(person) {
check(person, REQUIRED_FIELDS);
return Person.insert(person);
}
});
my-template.js
Template.myTemplate.events({
submit: function() {
var person = {
name: $('#name').val(),
gender: $('#gender').val(),
age: parseInt($('#age').val(), 10)
};
if (Person.isValid(person))
Meteor.call('person.insert', person);
else
alert('invalid person');
}
});
Here we are using meteor's check package to do some basic field validation. By adding an isValid helper to the Person collection, we can validate the schema without the need for a method call. Best of all we can reuse the same check when inserting a new document.