Progressive request

[noahfraiture]

Hello,

The article Progressive JSON has recently gained attention among content creators, and I had the idea for a similar concept in htmx. In brief, instead of receiving a complete payload in one go, a streaming response delivers data incrementally, with additional content arriving later. I recommend skimming the article for a clearer understanding.

We could envision an htmx feature where responses include an attribute, such as hx-swap-prog or hx-swap-progressive, to enable this progressive loading. It might work like hx-swap-oob and could be implemented as shown below:

<div id="messages" hx-swap-progressive="true"> /* refer to the id of the next element */
  this is a placeholder for messages
</div>

<div>
  You have 20 messages : 
  <div id="messages">$1</div>
</div>

/* $1 */
<div>Message 1</div>
<div>Message 2</div>

This approach allows responses to arrive faster, even if the full content is still being processed. For time-consuming requests, we often rely on <script> tags or libraries like Alpine.js to maintain responsiveness, but these cannot display partial request data until the entire response is ready. A progressive loading solution like this would address that limitation while staying true to htmx's idiomatic style.