Validate mass action column

Question

I am using Magento ver. 2.1.7 CE .

I added new button "Validate" in UI component layout as follows

<item name="buttons" xsi:type="array">          
<item name="print" xsi:type="array">
    <item name="name" xsi:type="string">print</item>
    <item name="label" xsi:type="string" translate="true">Validate</item>
    <item name="sortOrder" xsi:type="number">0</item>
    <item name="class" xsi:type="string">primary</item>
    <item name="url" xsi:type="string">*/*/save</item>
</item>
<item name="add" xsi:type="array">
    <item name="name" xsi:type="string">add</item>
    <item name="label" xsi:type="string" translate="true">Add New</item>
    <item name="class" xsi:type="string">primary</item>
    <item name="url" xsi:type="string">*/*/add</item>
</item></item>

I want to validate the checkbox for limit the selection not more than two items before submission.

If more than two selection, show popup message to user.

Thanks.

Answer 1

Instead of placing validate button you can validate records in mass action file.I think it is better option because if user forgot to click on validate and direct click on mass action then all selected record operation will be performed

Answer 2

Create a custom js in view->web->js->customname.js

require([
    "jquery",
    "customname"
    ], function($){
    $(document).ready(function() {

            $("#buttonid").click(function()
            {

                $(".admin__form-field-control .admin__control-select").val(this.id);        
                //call ajax here
            });

   });

in js file handle click event and get id of selected row and lastly include this js file in head section of your xml file