How to check for new entries periodically from the front-end?

Question

I would like to check periodically (every 5 seconds for example) whether there are new entries in a channel. If yes, I would like to present a refresh button on the website (with the number of the new entries).

So, I probably need a javascript which executes every 5 seconds a database query for the id of the latest entry and compares that to the last entry shown on the current page.

But I guess that javascript is not able to execute a database query, so I probably need a plugin for this.

Are my assumptions more or less correct? Where could I find a paid developper for such a plugin?

Thank you very much for your support.

Answer 1

This is actually a pretty simple task.

1. Create a template that your JS will reach out to returning the total number of entries. First create a template folder called "ajax" with an index.html file inside. Within that file put (replacing blogs with the name of your channel):

{{ craft.entries.section("blogs") | length }}

2. Inside your javascript, add this:

       var numberOfEntries = false;
   
       setInterval(function(){
   
       $.ajax({
         url: '/ajax',
         type: 'GET',
       })
       .success(function(data) {
   
         updatedNumberOfEntries = Number(data);
   
         if(updatedNumberOfEntries != numberOfEntries){
   
           // something was updated -- do whatever you want
           numberOfEntries = updatedNumberOfEntries;
   
         }
       });
   
       }, 5000);
   

You'll obviously need to make some revision to suit whatever you're trying to do but essentially just dump out the number of articles in a template, and use jquery's ajax method to get that value and see if it has changed.