Opal-Estate-Pro/assets/js/mortgage.js

( function ( $ ) {
    'use strict';
    $( document ).ready( function ( $ ) {
        if ( typeof opalestate_mortgage !== 'undefined' ) {
            var currency = opalestate_mortgage.currency;

            $( '.opalestate-mortgage-form input' ).change( function ( e ) {
                e.preventDefault();
                var $el = $( this ),
                    $widget = $el.closest( '.opalestate-mortgage-widget-wrap' );

                var sale_price = $widget.find( 'input[name="sale_price"]' ).val();
                var precent_down = $widget.find( 'input[name="deposit"]' ).val();
                var years = parseInt( $widget.find( 'input[name="years"]' ).val(), 10 );
                var interest_rate = parseFloat( $widget.find( 'input[name="interest_rate"]' ).val(), 10 ) / 100;

                var interest_rate_month = interest_rate / 12;
                var number_of_payments_month = years * 12;

                var loan_amount = sale_price - precent_down;
                var monthly_payment = parseFloat(
                    ( loan_amount * interest_rate_month ) /
                    ( 1 - Math.pow( 1 + interest_rate_month, -number_of_payments_month ) ) )
                    .toFixed( 2 );

                if ( monthly_payment === 'NaN' ) {
                    monthly_payment = 0;
                }

                var total = parseFloat( precent_down ) + parseFloat( monthly_payment * number_of_payments_month );
                var price_percent = loan_amount / total * 100;
                var deposit_percent = precent_down / total * 100;

                $widget.find( '.opalestate-monthly-value' ).html( currency + monthly_payment );

                $widget.find( '.opalestate-loan-amount-value' ).html( currency + loan_amount );

                $widget.find( '.opalestate-mortgage-chart-svg' ).html(
                    '<svg viewBox=\'0 0 64 64\' class=\'pie\'>' +
                    '<circle r=\'25%\' cx=\'50%\' cy=\'50%\' style=\'stroke-dasharray: ' + price_percent + ' 100\'>' +
                    '</circle>' +
                    '<circle r=\'25%\' cx=\'50%\' cy=\'50%\' style=\'stroke-dasharray: ' + deposit_percent + ' 100;' +
                    ' stroke:' + opalestate_mortgage.deposit_color +'; stroke-dashoffset: -' + price_percent + ';animation-delay: 0.25s\'>' +
                    '</circle>' +
                    '</svg>'
                );
            } );
        }
    } );
} )( jQuery );