feat: HttpClient, String&Date Utility classes, Transformer + updates …

…to QueryBuilder and SObjectSelector (#70)

* add generic httpclient

* update QueryBuilder with filter list

* Add utility classes for strings and dates

* add httpclient test class

* add transformer class and interface

* update sobjectselector

src/apex/utils/classes/DateFormatUtility.cls

@@ -0,0 +1,55 @@
+public class DateFormatUtility {
+    public class FormattingException extends Exception {
+    }
+
+    public static String formatDateTimeToString(DateTime inputDate) {
+        String formattedDate = DateTime.ValueOf(inputDate)
+            .format('dd MMM yyyy HH:mm');
+        return formattedDate;
+    }
+
+    public static String formatDateToString(Date inputDate, String dateFormat) {
+        return DateTime.newInstance(
+                inputDate.year(),
+                inputDate.month(),
+                inputDate.day()
+            )
+            .format(dateFormat);
+    }
+
+    public static DateTime parseDateTimeFromString(String dateString) {
+        if (dateString != null) {
+            return (DateTime) JSON.deserialize(
+                '"' + dateString + '"',
+                DateTime.class
+            );
+        }
+        return null;
+    }
+
+    public static Date parseDateFromString(String dateString) {
+        if (dateString != null) {
+            return (Date) JSON.deserialize('"' + dateString + '"', Date.class);
+        }
+        return null;
+    }
+
+    /**
+     * @description Takes in a list of strings and returns a date object. The list should contain the day, month and year in that order.
+     *
+     * @param dateList - A list of strings containing the day, month and year in that order.
+     */
+    public static Date parseDateFromString(String dateString, String format) {
+        if (format == 'dd.MM.yyyy') {
+            List<String> dateList = dateString.split('\\.');
+
+            return Date.newInstance(
+                Integer.valueOf(dateList[2]),
+                Integer.valueOf(dateList[1]),
+                Integer.valueOf(dateList[0])
+            );
+        }
+
+        return parseDateFromString(dateString);
+    }
+}

src/apex/utils/classes/DateFormatUtility.cls-meta.xml

@@ -0,0 +1,5 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<ApexClass xmlns="http://soap.sforce.com/2006/04/metadata">
+    <apiVersion>60.0</apiVersion>
+    <status>Active</status>
+</ApexClass>