In Meteor, a Spacebar template could include another template.
<template name="slots">
{{> slot }}
</template>
<template name="slot">
<div class="slot">
<div class="number">100</div>
</div>
</template>
Sometime we want to reuse the template with different variables. Here is an example.
<template name="slots">
{{> slot one}}
{{> slot two}}
{{> slot three}}
</template>
<template name="slot">
<div class="slot">
<div class="number">{{number}}</div>
</div>
</template>
1. Install the fibers node package on the server.
npm -g install fibers
2. Define the server methods in server.js.
server/server.js
Meteor.startup(function () {
// Load future from fibers
var Future = Npm.require("fibers/future");
// Load exec
var exec = Npm.require("child_process").exec;
// Server methods
Meteor.methods({
runCode: function () {
// This method call won't return immediately, it will wait for the
// asynchronous code to finish, so we call unblock to allow this client
// to queue other method calls (see Meteor docs)
this.unblock();
var future=new Future();
var command="pwd";
exec(command,function(error,stdout,stderr){
if(error){
console.log(error);
throw new Meteor.Error(500,command+" failed");
}
future.return(stdout.toString());
});
return future.wait();
}
});
});
Meteor doesn’t support distinct in query. Say, i have a dataset as follow.
{
"student":
[
{ "_id": "1", "class": "1A", "name": "Peter" },
{ "_id": "2", "class": "1A", "name": "Jack" },
{ "_id": "3", "class": "1B", "name": "Mary" },
{ "_id": "4", "class": "1C", "name": "Sam" },
{ "_id": "5", "class": "1C", "name": "Ann" },
]
}
What i would like to know is how many distinct classes are there. Here is the solution suggested by Jonathan Pidgeon from Empire5Design.
Continue reading Meteor – Distinct MongoDB Query
Say we have a Meteor collection called Student.
model.js
Student = new Meteor.Collection('student');
So i would like to have some predefined students if the collection is emtpy. So i prepare the student.json in the private folder.
private/student.json
{
"student":
[
{ "_id": "1", "name": "Peter" },
{ "_id": "2", "name": "Jack" },
{ "_id": "3", "name": "Mary" },
{ "_id": "4", "name": "Sam" },
{ "_id": "5", "name": "Ann" },
]
}
Continue reading Meteor – Insert Sample Data if the MongoDB is empty
In Meteor, it is very common to use the session variables.
// Save a value to x
Session.set("x", "eureka");
// Get the value of x
Session.get("x");
And sometimes we would like to use these session variables in the Handlebars template. This could be done by registering a helper in Handlebars.
Continue reading Meteor – Read session variables in Handlebars template
If you start a new Meteor app, it would initialize a local MongoDB instance. If you want to use a remote one. Add the MONGO_URL environmental variable before you start the Meteor app. Ex:
MONGO_URL = "mongodb://[username]:[password]@[host]:[port]/[db]"
Done =)
Reference: StackOverflow – How to connect meteor to an existing backend?
I was working on a Meteor project which is connected to a mongoDB hosted on MongoLab. Since it is a sandbox plan, the oplog of the mongoDB instance is not available and in that case the Meteor will keep polling the mongoDB in around every 10 seconds. This causes a very high consumption on CPU and network bandwidth.
If you are running, Meteor 0.7.0 or above and your mongoDB has oplog enabled. You won’t experienced the problem.
Since the oplog is not available so the only workaround which i could think of is to unsubscribe the dataset. Here is a main.js which is executed when the app is loaded and when the user is idle for than 3 mins. Stop the subscription and that will stop polling the mongoDB.
Continue reading Meteor – High Network IO as it keeps polling MongoDB
1. Start the meteor app.
2. Open another shell and connect to the app database which is also called meteor.
3. Check if you could find the collections there.
Done =)
Eureka! 