Wsrtjtyk

Today I try to work on meteor and getting an issue to get data from the server page..

I try to search it on google and meteor side but there is two way to get data publish / subscribe and Method

Have a below code, I didn't know how to write it on meteor server-side and get that data in client-side

function (x)

{

var y =2

var z  = y*x

return z;

}

Now I want to call this method in client side

With publish/subscribe you keep track on datas collected.
https://docs.meteor.com/api/pubsub.html

According to the documentation:

Methods are remote functions that Meteor clients can invoke with
Meteor.call.

So, to answer the last question: to call your function from client side, you have to use "Meteor.call('yourMethodName', optionalCallBacks);"

EDIT:

Ok, as suggested in the comments, here an example, with your function.
In the server side, lets say on a file called "methods.js" or somethings:

import { Meteor } from 'meteor/meteor';



Meteor.methods({

  myMethod(x) {

    const y = 2;

    const z = y * x;

    return z;

  }

});

then in client side, you could call this mehod, like:

Meteor.call('myMethod', x, (error, result) => {

  // OPTIONAL CALLBACK RESULT

  console.log(error, result);

});

Arguments here, are respectivelly, name of the method, variable named x, callback.

What is the difference between publish / subscribe and method ? where/when we use method and publish / subscribe?

So if you want a logic you don't need pub/sub.
Methods are for logic pub/sub for data handling.

Important note:
If you need to work with data from meteor's collection on the method you need to take into account this if method is executed on the server side it has access to all data (collections).
If the method is executed on the client side it has access only to published data.

On the other hand, according to your example, you don't need any data, so I'll skip it.

I strongly suggest using validated methods:

https://github.com/meteor/validated-method

Now let's go to examples

Imagine you have a method

export const calculate = new ValidatedMethod({

  name: 'logic.calculate', // methods are usually named like this

  validate: new SimpleSchema({ // use SimpleSchema to autovalidate parameters

    x: {

      type: Number

    }

  }).validator(),

  run({ x }) {

    const y = 2;

    return y*x;

  }

});

Things to note:
1. The file should be imported on the server somewhere.
2. You need to use validation

Now call it on the client

Meteor.call('logic.calculate', { x }, (error, result) => {

  if (error) {

    do something

  }

  console.log(result);

});

Also, you can import the method directly and call it like this:

import { calculate } from '../../api/logic/methods';// use real method path here   



calculate.call({ x }, (error, result) => {

     if (error) {

        do something

     }

     console.log(result);

});

Note that for validated methods argument is an object

In meteor, we can create a meteor method and can pass data to client side by Meteor.call('methodName', 'param') . But in case of async operation we need to use future. Take a look on below example :

Future = Npm.require('fibers/future');



Meteor.methods({

  foo: function() {

    const future = new Future();

    someAsyncCall(foo, function bar(error, result) {

      if (error) future.throw(error);

      future.return(result);

    });

    // Execution is paused until callback arrives

    const ret = future.wait(); // Wait on future not Future

    return ret;

  }

});