htmx_dash

Overview

This is an experiment/demo of how to use (htmx)[https://htmx.org/] to build a dashboard. The ideas is to use it for an embedded device with network capabilities but no internet access (local area networks). Even though it should work with multiple clients, it was designed for a single client.

This demo builds an executable with all dependencies embeded in the binary. It makes use of the http-server in the go standard library to present a htmx-page with three sections: Status, Config, Log.

Status

The server updates this section periodically. It can not be modified by the client. The client polls this section periodically.

Config

This section gets updated by the client. The config can be edited with a form, that is rendered when pressing the 'Edit'- Button. It can be Canceled or Saved. If there are any parsing errors or the values are not in range, then the user is presented with the error and given the opportunity to adjust or Cancel the operation.

Log

This section is polled periodically by the client using 'load delay:xs'. It passes a sequence number to the server. The server filters out all messages, that the client received already and sends the rest with the updated sequence number to the client. After the load delay, the client will then issue another request with the updated sequence number. The server stores only very few log messages and they are stored in the dom on the client side by appending to the table. If the server detects, that there is a gap in the sequence number of the request and the last stored log message. It will let the client know, that it dropped x messages. This happens for example when the page is loaded for the fist time.

Build and Run

Download htmx.min.js and put it in the same directory as main.go. If you do not want to embed the library into the executable, replace the script tag in the index.html as per the documentation to make use of a content delivery network (and remove the respective code from main.go). This path is not chosen for the demo, because the demo assumes, that internet access is not available.

Build the binary with go build and run the created binary or use go run main.go instead.