Comparable Interface in Salesforce

The Comparable interface adds sorting support for Lists that contain non-primitive types, that is, Lists of user-defined types.

To add List sorting support for your Apex class, you must implement the Comparable interface with its compareTo method in your class.

When a class implements the Comparable interface it has to implement a method called compareTo(). This method returns an integer value that is the result of the comparison.

compareTo(objectToCompareTo)
Returns an integer value that is the result of the comparison.

The implementation of this method returns the following values:

0 if this instance and objectToCompareTo are equal
> 0 if this instance is greater than objectToCompareTo
< 0 if this instance is less than objectToCompareTo

If this object instance and objectToCompareTo are incompatible, a System.TypeException is thrown.

Example:

global class Employee implements Comparable {

    public Long id;
    public String name;
    public String phone;
    
    // Constructor
    public Employee(Long i, String n, String p) {
        id = i;
        name = n;
        phone = p;
    }
    
    // Implement the compareTo() method
    global Integer compareTo(Object compareTo) {
        Employee compareToEmp = (Employee)compareTo;
        if (id == compareToEmp.id) return 0;
        if (id > compareToEmp.id) return 1;
        return -1;        
    }
}

Sort the List using compareTo(object) method.

List<Employee> empList = new List<Employee>();
empList.add(new Employee(101,'Joe Smith', '4155551212'));
empList.add(new Employee(101,'J. Smith', '4155551212'));
empList.add(new Employee(25,'Caragh Smith', '4155551000'));
empList.add(new Employee(105,'Mario Ruiz', '4155551099'));

// Sort using the custom compareTo() method
empList.sort();

// Write list contents to the debug log
for (Employee emp : empList){
 system.debug(emp);
}

Output

Format Dates and Time using Apex in Salesforce

This post explains how to format dates and times using apex.
The below table contains the formatting codes.

Letter	Date or Time Piece	Examples
G	Era	G = AD
y	Year	yy = 09, yyyy = 2009
M	Month	MM = 08, MMM = Aug, MMMMM = August
w	Week in year	w = 35
W	Week in month	W = 3
D	Day in year	D = 235
d	Day in month	dd = 27
F	Day of week in month	F = 2
E	Day in week	E = Thu, EEEEE = Thursday
a	AM/PM	a = AM or PM
H	Hour in day (0-23)	HH = 23
k	Hour in day (1-24)	kk = 24
K	Hour in am/pm (0-11)	KK=11
h	Hour in am/pm (1-12)	hh = 12
m	Minutes in hour	mm = 30
s	Second in minute	ss = 55
S	Millisecond in second	SSS = 888
z	Time zone	z = EDT, zzzzz = Eastern Daylight Time
Z	Time zone offset	Z = -0400

Examples

DateTime dt = Datetime.now();
String strTimeInAMorPM = dt.format('MMMMM dd, yyyy hh:mm:ss a');
System.debug('time in am and pm ==> '+strTimeInAMorPM); 

String strTimeInWeek = dt.format('MMMMM dd, yyyy EEEE');
System.debug('strTimeInWeek ==> '+strTimeInWeek); 

String strTimezone = dt.format('MMMMM dd, yyyy z');
System.debug('strTimezone ==> '+strTimezone); 

Output

Handle Custom Validations in Lightning Web Components(lwc)

When we working with input values some times users enter the bad data, In this situation we need to validate the data and show the custom error message to the user to correct the data.

Use the setCustomValidity() and reportValidity() methods to validate and dsiplay custom error message.

Demo:
HTML Code

<template>
    <lightning-card title="Custom Validations In Lightning Web Components">
        <lightning-input class="nameCmp" label="Enter Name" type="string"></lightning-input>
        <lightning-input class="dateCmp" label="Enter Date" type="date"></lightning-input><br/><br/>
        <lightning-button class="slds-align_absolute-center" label="Search" variant="brand" onclick={searchTheData}></lightning-button>
    </lightning-card>
</template>

Javascript Code

import { LightningElement, track } from 'lwc';

export default class DemoApp extends LightningElement {

    searchTheData() {
        let searchCmp = this.template.querySelector(".nameCmp");
        let dateCmp = this.template.querySelector(".dateCmp");
        let searchvalue = searchCmp.value;
        let dtValue = dateCmp.value;
       
        if (!searchvalue) {
            searchCmp.setCustomValidity("Name value is required");
        } else {
            searchCmp.setCustomValidity(""); // clear previous value
        }
        searchCmp.reportValidity();

        if (!dtValue) {
            dateCmp.setCustomValidity("Date value is required");
        } else {
            dateCmp.setCustomValidity(""); // clear previous value
        }
        dateCmp.reportValidity();
    }
}

Output