datastar/site/static/md/examples/value_select.md

Cascading Selects

Original HTMX Version

Demo

Explanation

In this example we show how to make the values in one select depend on the value selected in another select.

To begin we start with a default value for the make select: Audi. We render the model select for this make. We then have the make select trigger a GET to /models to retrieve the models options and target the models select.

Here is the code:

<div id="value_select" data-signals='{"make":"","model":""}'>
  <div>Pick a Make / Model</div>
  <select data-bind="make" data-on-change="@get('/examples/value_select/data')">
    <option disabled>Select a Make</option>
    <option value="HYAABHANLTMQC">Audi</option>
    <option value="HZAABHANLTMQC">Toyota</option>
    <option value="H2AABHANLTMQC">Ford</option>
  </select>
</div>

When a request is made to the /models end point, we return the models for that make:

<div id="value_select" data-signals='{"make":"HZAABHANLTMQC","model":""}'>
  <div>Pick a Make / Model</div>
  <select data-bind="make" data-on-change="@get('/examples/value_select/data')">
    <option disabled>Select a Make</option>
    <option value="HYAABHANLTMQC">Audi</option>
    <option value="HZAABHANLTMQC">Toyota</option>
    <option value="H2AABHANLTMQC">Ford</option>
  </select>
  <select
    data-bind="model"
    data-on-change="@get('/examples/value_select/data')"
  >
    <option disabled="" selected="" value="">Select a Model</option>
    <option value="HZIABHANLTMQC">Land Cruiser</option>
    <option value="HZQABHANLTMQC">Corolla</option>
    <option value="HZYABHANLTMQC">Camry</option>
  </select>
</div>

And they become available in the model select.