Yii 2.0 Scenarios - Dynamic Validation - validation

Question

I have a situation where I would like to validate a textbox input; however, the type of validation is dependent on the selection of a dropdown list on that page (there would be multiple of each of these on a page). So, the textbox can take a string, an integer, a date, etc. and the user must select something from the dropdown list that would tell me what the data type has to be that the user will enter.
I was thinking to use scenarios for this; however, the textbox is 1 field in my model/database that accepts a string at the database level (I just don't want the user to enter a string when an integer is appropriate regardless of how I handle on the backend).
Here's what I was thinking so far, but I don't know if this is the best route to take for this problem? Also, if I can use the scenarios for this then how do I specify in the view the rules for the textbox when a user selects something that requires i.e..date input? Is there a way that I could call the rule with Ajax on click of dropdown list?? Sorry, this is probably a little too broad a question, but I'm new to Yii and I'm just trying to get headed down the right path with this. Thank you!
public function scenario()
{
return[
'isstring' => ['filter_value'],
'isint' => ['filter_value'],
'isdate' => ['filter_value'],
'isfloat' => ['filter_value'],
'all' => ['freq_int', 'freq_unit_fk', 'filter_field_fk', 'arithmetic_op', 'logic_op', 'filter_value']
];
}
public function rules()
{
return [
[['freq_int', 'freq_unit_fk'], 'integer', 'message' => 'Integer'],
[['freq_int', 'freq_unit_fk', 'filter_field_fk', 'arithmetic_op'], 'required'],
[['logic_op'], 'safe'],
[['filter_value'], 'integer', 'on' => 'isint'],
[['filter_value'], 'string', 'min' => '2', 'max' => '75', 'on' => 'isstring'],
[['filter_value'], 'trim', 'on' => 'isstring'],
[['filter_value'], 'number', 'on' => 'isfloat'],
[['filter_value'], 'date', 'on' => 'isdate']
];
}
Ok, so to give more detail, and I've decided to drop the idea of having the validation set based on a dropdown selection for now. Instead, it just needs to get set based on a value that I'm getting from the database when the page gets loaded. I have a partial view file called '_settings.php' and it gets rendered as a modal through a view file called 'manage.php'. Here is the code in _settings.php that displays the text boxes that I'm trying get the validation to work on:
foreach($crystalfields as $field)
{
if($field['custom'] == 4)
{
$datatype = $model->getDatatypeName($field['datatype']);
$filterstring = $form->field($model, 'filter_value', ['inputOptions' => ['id' =>'filterval'.$crystalid.'-'.$field['fieldid']]])
->textinput(['name' => 'filterval'.$crystalid.'-'.$field['fieldid']])
->label(false);
$filterstrings = $filterstrings.'<div class="form-group">
<div class="form_group row">
<label for="filterval'.$crystalid.'-'.$field['fieldid'].'" class="col-sm-3 control-label">'.$field['fieldname'].'</label>
<div class="col-sm-6 pull-right">'.$filterstring.'</div>
</div>
</div>';
}
...there is more to the foreach loop that is irrelevent. Basically, what I want to do is have the validation for this text box be set based on the result of the method $model->getDatatypeName($field['datatype']) ... method is part of my model where the validation rules exist; however, the primary key $field['datatype'] that I'm passing to this method is based on a query that is joining many related tables in my view model ..$model in this case. So when this method passes back 'string' I want to set the validation accordingly. There can be multiple of these text boxes within the modal that each have different validation types but are attached to the same 'filter_value' field each time.

Answer 1

I think the easier solution here would be to use the when-functionality. This gives you fine control over whether the rule should be triggered:
public function rules()
{
return [
[['freq_int', 'freq_unit_fk'], 'integer', 'message' => 'Integer'],
[['freq_int', 'freq_unit_fk', 'filter_field_fk', 'arithmetic_op'], 'required'],
[['logic_op'], 'safe'],
[['filter_value'], 'integer', 'when' => function ($model) {return $model->logic_op == 'integer'; }],
[['filter_value'], 'string', 'min' => '2', 'max' => '75', 'when' => function ($model) {return $model->logic_op == 'string'; }],
[['filter_value'], 'trim', 'when' => function ($model) {return $model->logic_op == 'string'; }]],
[['filter_value'], 'number', 'when' => function ($model) {return $model->logic_op == 'float'; }]],
[['filter_value'], 'date', 'when' => function ($model) {return $model->logic_op == 'date'; }]]
];
}