How to change the field value in update form in Yii2 - yii2

Question

In my update form, I want to show the original value rather than it's id. Below is my _form.
<div class="mdc-meter-config-form">
<?php $form = ActiveForm::begin(['id'=>'con','options' => ['enctype' => 'multipart/form-data']]) ?>
<label class="control-label">Select Meters</label><br />
<input type="text" id="the-mter-id" class="form-control col-md-12" value="<?=$model->meter_id?>" />
<div style="clear: both;"></div>
<div id="selected_mters_container"></div>
<div style="clear: both;"></div>
<br/>
<?= $form->field($model, 'p_id')->dropDownList([''=>'Please Select']+\common\models\MdcProtocol::toArrayList()) ?>
<?= $form->field($model, 'time')
->dropDownList([''=>'Please Select','5' => '5', '10' => '10', '15' => '15','20'=>'20'])->label("Set Time (in seconds)") ?>
<div class="form-group">
<?= Html::submitButton(Yii::t('app', 'Save'), ['class' => 'btn btn-success']) ?>
</div>
<?php ActiveForm::end(); ?>
In above view I want to change the 2 value to its actual one which is 4A60193390662

Answer 1

Dont know why you are not using the relation here for the meter to display the meter serial rather than the id.
Easiet way to avoid any further work as you want to just display it, 2 things you need to do
Assign the value to the input manually via relation.
Make the field disabled to exclude it out of the model collection array. (in case you use active form for the field).
I assume you have a relation to the meter in your current model with name getMeter() and the number you are trying to display 4A60193390662 is in field serial_number. You can change accordingly.
If you havent defined a relation than define one now
public function getMeter(){
return $this->hasOne(Meter::class,['id'=>'meter_id']);
}
Although you are using a custom html field you can still use the active form and mark the field disabled so that the activeform wont submit it with the model collection array and there wont be errors when saving the records like
meter_id should be an integer.
echo $form->field($model, 'meter_id')->textInput(['disabled' => 'disabled', 'value' => $model->meter->serial_number]);

Answer 2

try add an entry also for the field with value 4A60193390662 eg: $model->meter_name
<input type="text" id="the-mter-name" class="form-control col-md-12" value="<?=$model->meter_name?>" />
and if you don't want see the entry for meter_id .. you could use hidden input for this so mantain the related avlue for the model loading and popolation
And as suggested in comment by Michal Hyncica (sorry for improper charset ) you could wrap the input inside a check fo new record
<?php
if(!$model->isNewRecord) {
echo '<input type="text" id="the-mter-name" class="form-control col-md-12" value="' . $model->meter_name . '" />';
}