Why can't pass the value of submitButton?

Question

Yii

Good day to all!
I will describe the view in order

<?php
    use yii\helpers\Html;
    use yii\widgets\ActiveForm;
    use yii\widgets\Pjax;
?>

<?php Pjax::begin(); ?>

    <?= Html::beginForm(['exem/exem'], 'post', ['data-pjax' => '', 'class' => 'form-inline']); ?>

    <?= Html::submitButton('-', ['name' => 'minus', 'value' => 'minus', 'class' => 'btn red']); ?>

    <?= Html::input('number', 'number', $stringHash , ['class' => 'form-control']) ?>

    <?= Html::submitButton('+', ['name' => 'plus', 'value' => 'plus', 'class' => 'btn blue']); ?>

    <?= Html::endForm() ?>

    <?php Pjax::end(); ?>

controller:

<?php
namespace frontend\controllers;
use yii\web\Controller;
use Yii;
use yii\base\Security;

class ExemController extends Controller {
    
    public function actionExem()
    {
       
        $string = 1;
  
        if(isset($_POST['minus']) == 'minus') 
         {
             $string = Yii::$app->request->post('number') -1;
         }

          if(isset($_POST['plus']) == 'plus') 
          {
            $string = Yii::$app->request->post('number') +1;
          }
        
        return $this->render('pjax', [
            'stringHash' => $string,
        ]);
    }           
}

When you try to get the value of the button (any), nothing happens, i.e. only the value of the input field is passed. What am I doing wrong?

Answer 1

I fixed it right away, sorry for not editing the topic. When submitting the form, in the debugger I see that there are only two values ​​in $superglobal->POST: one is obtained from the input field, and the second I don’t know exactly what it is, but these are not the values ​​from the submitButton button.
In general, I solved the problem as follows:

.center{
width: 150px;
  margin: 40px auto;  
}

<link href="//netdna.bootstrapcdn.com/bootstrap/3.1.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.1.0/js/bootstrap.min.js"></script>
<script src="//code.jquery.com/jquery-1.11.1.min.js"></script>

<div class="center">
    <div class="input-group">
          <span class="input-group-btn">
              <button type="button" class="btn btn-danger btn-number"  data-type="minus" data-field="quant[2]">
                <span class="glyphicon glyphicon-minus"></span>
              </button>
          </span>
          <input type="text" name="quant[2]" class="form-control input-number" value="10" min="1" max="100">
          <span class="input-group-btn">
              <button type="button" class="btn btn-success btn-number" data-type="plus" data-field="quant[2]">
                  <span class="glyphicon glyphicon-plus"></span>
              </button>
          </span>
      </div>
</div>

$('.btn-number').click(function(e){
    e.preventDefault();
    
    fieldName = $(this).attr('data-field');
    type      = $(this).attr('data-type');
    var input = $("input[name='"+fieldName+"']");
    var currentVal = parseInt(input.val());
    if (!isNaN(currentVal)) {
        if(type === 'minus') {
            
            if(currentVal > input.attr('min')) {
                input.val(currentVal - 1).change();
            } 
            if(parseInt(input.val()) === input.attr('min')) {
                $(this).attr('disabled', true);
            }

        } else if(type === 'plus') {

            if(currentVal < input.attr('max')) {
                input.val(currentVal + 1).change();
            }
            if(parseInt(input.val()) === input.attr('max')) {
                $(this).attr('disabled', true);
            }

        }
    } else {
        input.val(0);
    }
});

Answer 2

In the if sections, you are isset() comparing against a string. Although isset() returns a boolean value.