I have tried to bring multi selection for one2many field in the form view, Version 12.0. But didn't find any helpful thread. And later i have tried with a custom module for the same purpose which was in version 10.0. I have made a few changes in the js file and after installing it. I can find that everything else in that module works fine but not the multi selection checkbox.

odoo.define('web_one2many_selectable_10.form_widgets', function (require) {

	"use strict";



	var core = require('web.core');

	

	console.log(core)

	var _t = core._t;

	var QWeb = core.qweb;

	var field_registry = require('web.field_registry');

	

	var FieldOne2Many = field_registry.get('one2many');





	var One2ManySelectable = FieldOne2Many.extend({

		

		template: 'One2ManySelectable', 

		multi_selection: true,

		supportedFieldTypes: ['one2many'],

		

		events: {

			"click .cf_button_confirm": "action_selected_lines",

		},

		start: function() 

	    {

	    	this._super.apply(this, arguments);

			var self=this;			

		   },

		

		action_selected_lines: function()

		{		

			var self=this;

			var selected_ids = self.get_selected_ids_one2many();

			if (selected_ids.length === 0)

			{

				this.do_warn(_t("You must choose at least one record."));

				return false;

			}

			var model_obj=new Model(this.dataset.model); 



			model_obj.call('bulk_verify',[selected_ids],{context:self.dataset.context})

			.then(function(result){

			});

		},

		
		get_selected_ids_one2many: function ()

		{

			var ids =[];

			this.$el.find('td.o_list_record_selector input:checked')

					.closest('tr').each(function () {

						

						ids.push(parseInt($(this).context.dataset.id));

						console.log(ids);

			});

			return ids;

		},





	});


	field_registry.add('one2many_selectable', One2ManySelectable);

});

This is the file in which i have made changes. Is there any way to solve the issue.

Thanks in advance