有没有办法只有在 php 中选择了选项后才显示命令

Question

I can't figure out on how to put the selected code after it has selected the option.

I am using laravel, but i dont think it has to do with laravel framework...

<select id="idjenisuniform" name="idjenisuniform"  style="width: 100%;">
   <option value=""></option>
       @foreach($idjenisuniform as $g)
          <option value="{{$g->id}}" >{{$g->badanuniform}}</option>
       @endforeach
</select>

(the idjenisuniform is from the controller, it works), but I just don't know how to do it after it has done choosing from the option.

Example

it chooses police -> the id is 1

I want to make:

if the option from it is 1 , then it will display other option to show what group is he in. For example detective .

In conclusion I am trying to make a select option and after it has choose it, it will proceed to the next select option corresponding to the previous id from option.

please help.

Answer 1

Since you are wanting an effect that depends on user interaction, it would be better to use javascript for the effect you want. With php, the choice has to go all the way back to the web server to get processed, then the result is sent all the way back to the browser and the whole web page will refresh as a result. With javacript, everything happens in the browser.

But, you asked for a php solution, so here's the most simple way. Say the first select element is named "select-one" and the second select element is named "select-two"

Create two forms. Notice that the second form has an ID.

[form action="/url/" method="whatever"]
[form id="other-form" action="/url/" method="post"]

In the main form (the one without an ID), place all your form elements. In addition, place another hidden element with the same name as the first select element ("select-one");

[form]
[input type="hidden" name="select-one"]
... all other elements
[/form]

Now when you add the first select element, give it a new attribute so that it is associated with "other-form" instead of the main form. Also, give it an ID.

[select id="select1" name="select-one" form="other-form"]

You DO have to add a bit of javascript, but it's not much. If you don't have any other javascript set up, just put this at the bottom of the web page, just above the [/body] tag.

[script]
const select1 = document.querySelector('#select1');
select1.addEventListener('change', (event) => event.target.form.submit());
[/script]

The javascript will submit the form which #select1 is associated with. Since we assigned the element to "other-form", that is the form that will get submitted.

For the php: I haven't used Laravel in a very verly long time so I'll just give some vanilla php here.

$options_one = ['One', 'Two', 'Three'];

$options_two = [
  'One' => ['Foo', 'Bar', 'Baz'],
  'Two' => ['Boom', 'Bang', 'Bam'],
  'Three' => ['Fee', 'Fie', 'Fo', 'Fum']
];

$select_one = (isset ($_POST['select-one']) ? $_POST['select_one'] : false;
// do some input validation

Now for the forms:

<form id="other-form" method="post" action = ""></form>

<form id="main-form" action="">
  <input type="hidden" name="select-one" value="<?php echo $select_one ?>">

  <!-- This element is assigned to "other-form" -->
  <select form="other-form" name="select-one" id="select1">
    <option value="">Select One...</option>
    <?php foreach($options_one as $option) {
      $option = ($select_one === $option) ? "<option selected>$option</option>" : "<option>$option</option>";
      echo $option;
    }?>
  </select>

  <select name="select-two">
    <?php
    $options = ["The first choice has not been selected"];

    if (array_key_exists($select_one, $options_two)) {
      $options = $options_two[$select_one];
    }

    foreach ($options as $option) {
      echo "<option>$option</option>";
    }
    ?>
  </select>

  <!-- other inputs in your form -->
</form>