The earlier approach of loading `/api/config.js` as a script on
initial page load with the necessary variables to init the UI is
ditched. Instead, it's now `/api/config` and `/api/settings` like
all other API calls. On load of the frontend, these two resources
are fetched and the frontend is initialised.
In addition to generating HTML forms for selected public lists,
the form page now shows a URL (/subscription/form) that can be
publicly shared to solicit subscriptions. The page lists all
public lists in the database. This page can be disabled on the
Settings UI.
This commit removes the Go html2text lib that would automatically
convert all HTML messages to plaintext and add them as the alt
text body to outgoing e-mails. This lib also had memory leak
issues with certain kinds of HTML templates.
A new UI field for optionally adding an alt plaintext body to
a campaign is added. On enabling, it converts the HTML message in
the campaign editor into plaintext (using the textversionjs lib).
This introduces breaking changes in the campaigns table schema,
model, and template compilation.
Certain SMTP hosts limit the total number of messages that can be
sent within a window, for instance, X / 24 hours. The concurrency
and message rate controls can only limit that to a max of
1 messages / second, without a global cap.
This commit introduces a simple sliding window rate limit feature
that counts the number of messages sent in a specific window, and
upon reaching that limit, waits for the window to reset before
any more messages are pushed out globally across any number of
campaigns.
Context: https://github.com/knadh/listmonk/issues/119
