Thank you for your help but i read this documentation before i create this topic.
In this duration to you response i found a solution. I'll share it with you. maybe someone need it in the feature.
I simulated the process of creating hikashop's custom fields in the plugin.
1- First of all you need create columns with name of your field in hikashop category table (#__hikashop_category)
2- Then you need append the fields you want to create with bellow structure to the $viewObj->fields array in onHikashopBeforeDisplayView event.
Note: The structure is the same for all type of field but there is some change with field type like singledropdown or textbox , ...
You can find more about the fields type special serialized data by creating filed in hikashop custom filed and looking to the #__hikashop_field table.
it so important to know the array key in $viewObj->fields is your field name and value should be an object.
Code:
$viewObj->fields['namekey_of_field'] = (object) [
'field_id' => '',
'field_table' => 'category',
'field_realname' => '',
'field_namekey' => '',
'field_type' => 'text',
'field_value' => '',
'field_published' => 1,
'field_ordering' => 1,
'field_options' => [
'errormessage' => '',
'regex' => '',
'attribute' => '',
'placeholder' => '',
'inline' => '0',
'target_blank' => '1',
'allow_add' => '0',
'cols' => '',
'filtering' => '1',
'maxlength' => '0',
'rows' => '',
'zone_type' => 'country',
'pleaseselect' => '0',
'size' => '',
'format' => '%Y-%m-%d',
'allow' => '',
'allowed_extensions' => '',
'upload_dir' => '',
'max_filesize' => '0',
'max_width' => '0',
'max_height' => '0',
'multiple' => '0',
'readonly' => '0',
'mysql_query' => '',
'datepicker_options' => [
'today' => '0',
'inline' => '0',
'monday_first' => '0',
'change_month' => '0',
'change_year' => '0',
'year_range_start' => '',
'year_range_end' => '',
'show_btn_panel' => '0',
'show_months' => '1',
'other_month' => '0',
'exclude_days_format' => 'mdY',
'waiting' => '',
'hour_extra_day' => '',
'check_dates' => 'all'
]
],
'field_core' => 0,
'field_required' => 0,
'field_default' => '',
'field_access' => 'all',
'field_categories' => 'all',
'field_with_sub_categories' => 0,
'field_products' => '',
'field_address_type' => '',
'field_frontcomp' => 0,
'field_backend' => 1,
'field_backend_listing' => 0,
'field_display' => null,
'field_shipping_id' => '',
'field_payment_id' => '',
'guest_mode' => true,
'field_url' => str_replace('/', '\/', JURI::base()) . '/administrator\/index.php?option=com_hikashop&ctrl=field&task=state&tmpl=component&'
];
