Magento 2 : Display Loader While Ajax call in custom Knockout js

Question

I am using this extension which adds extra fee to quote after select a particular payment. After selecting any payment option it is making an ajax call, I want to show loader until the ajax request is completed. below is my js file

define(
    [
        'ko',
        'jquery',
        'Magento_Checkout/js/model/quote',
        'Magento_Checkout/js/model/resource-url-manager',
        'Magento_Checkout/js/model/payment-service',
        'mage/storage',
        'mage/url',
        'Magento_Checkout/js/action/get-totals',
        'mage/translate',
        'Magento_Checkout/js/model/payment/method-list'
    ],
    function(
        ko,
        $,
        quote,
        urlManager,
        paymentService,
        storage,
        urlBuilder,
        getTotalsAction
    ) {
        'use strict';

        return function (isLoading, payment) {
            var serviceUrl = urlBuilder.build('paymentfee/checkout/totals');
            return storage.post(
                serviceUrl,
                JSON.stringify({payment: payment})
            ).done(
                function(response) {
                    if(response) {
                        var deferred = $.Deferred();
                        isLoading(false);
                        getTotalsAction([], deferred);
                    }
                }
            ).fail(
                function (response) {
                    isLoading(false);
                    //var error = JSON.parse(response.responseText);
                }
            );
        }
    }
);

I tried injecting 'Magento_Checkout/js/model/full-screen-loader' class and then use fullScreenLoader.startLoader(); but it is not working.

Can anyone suggest me how to show loader image on checkout page ?

Answer 1

You can show default loader in magento by using the following code

var body = $('body').loader();
body.loader('show'); 

If you want to hide use the following code

var body = $('body').loader();
body.loader('hide');

OR

jQuery('body').loader('destroy');

OR

var body = $('body').loader();
body.loader('destroy');

Answer 2

You can try for start:

jQuery('body').trigger('processStart');

OR

$('body').trigger('processStart');

And for remove:

jQuery('body').trigger('processStop');

OR

$('body').trigger('processStop');

See example

Answer 3

All answers on this page are wrong. You need to add the model 'Magento_Checkout/js/model/full-screen-loader' to your define section, and then use it to show/hide the loader.

The code below is from vendor/magento/module-negotiable-quote/view/frontend/web/js/action/set-payment-information-mixin.js. Note how it calls fullScreenLoader.startLoader() and then fullScreenLoader.stopLoader() after the storage.post is complete:

define([
    'mage/utils/wrapper',
    'mage/storage',
    'Magento_Checkout/js/model/quote',
    'Magento_Checkout/js/model/url-builder',
    'Magento_Checkout/js/model/error-processor',
    'Magento_Checkout/js/model/full-screen-loader'
], function (wrapper, storage, quote, urlBuilder, errorProcessor, fullScreenLoader) {
    'use strict';

    return function (setPaymentInformation) {
        return wrapper.wrap(setPaymentInformation, function (originalAction, messageContainer, paymentData) {
            var serviceUrl, payload;

            if (window.checkoutConfig.isNegotiableQuote) {
                serviceUrl = urlBuilder.createUrl('/negotiable-carts/:cartId/set-payment-information', {
                    cartId: quote.getQuoteId()
                });
                payload = {
                    cartId: quote.getQuoteId(),
                    paymentMethod: paymentData,
                    billingAddress: quote.billingAddress()
                };

                fullScreenLoader.startLoader();

                return storage.post(
                    serviceUrl, JSON.stringify(payload)
                ).fail(function (response) {
                    errorProcessor.process(response, messageContainer);
                }).always(fullScreenLoader.stopLoader);
            }

            return originalAction(messageContainer, paymentData);
        });
    };
});