Reactive publication/subscription using Meteor

client.js

Deps.autorun(function() {
  Meteor.subscribe('messages', Session.get('query'));
})

server.js

Meteor.publish('messages', function(query) {
  return Messages.find({messagecontent: query});
});

template.html

<template name="yourTemplateName">
  <input type="text">
  <ul>
    {{#each messages}}
      <li>{{messagecontent}}</li>
    {{/each}}
  </ul>
</template>

template.js

Template.yourTemplateName.events({
  //listen on input
  'keyup input': function(event) {
    //if enter was hit
    if(event.type === 'keyup' && event.which === 13) {
      //set query as input box text
      Session.set('query', $(event.target).text());
    }
  }
});

Template.yourTemplateName.helpers({
  messages: function() {
    return Messages.find({});
  }
});