Question

I built the application and it is taking time to load the initial set of data from mongodb and I want to show the loadin gif till the data loading is done. Could you please help me in doing this?

Answer 1

Use Session inside the onReady() callback of the Meteor.subscribe() function, which is invoked when the subscription is completed.

Meteor.subscribe('subscribe_to_this', function onReady(){
         // set a session key to true to indicate that the subscription is completed.
         Session.set('subscription_completed', true);
});

Then make this session value to be returned from your template helper as:

Template.myTemplate.isSubscriptionComplete = function(){
     return Session.get('subscription_completed'); 
}

Now in your html, it is easy to display a loader if data is not loaded or to render a template, if the data has completed loading.

<template name="myTemplate">
    {{#if isSubscriptionComplete }}
          <!-- Data loading is done, so render your template here -->
          {{> yourFinalTemplate}}
    {{else}}
          <!-- Data loading still remaining, so display loader here -->
         <img src="images/load.gif">
    {{/if}}
</template>