USE DHVC FORM FOR VISUAL COMPOSER OLD VERSION < 4.0
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  Use DHVC Form for Visla Composer old version < 4.0 (example in Salient theme use 3.7.3).
  Please go to file "js_composer/assets/js/backend/composer-view.js"  (in Salien theme go to file "salient/wpbakery/js_composer/assets/js/backend/composer-view.js") line #689 search code like:
  ------
  
  getParams: function() {
	var attributes_settings = this.mapped_params,
	    params = jQuery.extend(true, {}, this.model.get('params'));
	_.each(attributes_settings, function (param) {
	    params[param.param_name] = vc.atts.parse.call(this, param);
	}, this);
	return params;
  }
  
  ------
  then replace code in "getParams" function:
  ------
  
   var attributes_settings = this.mapped_params,
	    params = jQuery.extend(true, {}, this.model.get('params'));
	_.each(attributes_settings, function (param) {
	    params[param.param_name] = vc.atts.parse.call(this, param);
	}, this);
	return params;
	
   ------
   to:
   ------
   
	var attributes_settings = this.mapped_params;
	this.params = jQuery.extend(true, {}, this.model.get('params'));
	_.each(attributes_settings, function (param) {
		this.params[param.param_name] = vc.atts.parse.call(this, param);
	}, this);
	_.each(vc.edit_form_callbacks, function(callback){
		callback.call(this);
	}, this);
	return this.params;