How to get the list of attachments (notes) related to an EmailTemplate in SugarCRM?

I'm using SugarCRM Enterprise, Version 8.1.0 (Build 135) (Summer '18), the cloud version and I need, from an external site, to get the list of all EmailTemplates and for earch EmailTemplate the list of its attachments (or Notes), via the API.

I can list all EmailTemplates but can't find, for each of them, the list of attached files, what do I have to do (with the API)?

Solution

One way to do this is to use the Filter API on the Notes module to get the attachments for each EmailTemplate. This is the only way I found so far, as using the "attachments" link in EmailTemplates did not yield any results...

Example: POST request to /rest/v11_2/Notes/filter with following payload:

{
    max_num: 1000,
    fields: ["id", "name"], /* specify the fields you want to receive */
    filter: [
        {"email_id": "<id of the email template goes here>"},
    ],
}

For more info regarding the filter API see "POST /<module>/filter" at <sugar_site>/rest/v11_2/help

Notes:

In older versions of Sugar (before Sugar 8) the relationship looked different, so the filter there should look like this: {filter: [{parent_type:"Emails", parent_id: "<id of the email template goes here>"}]}