Post 3 – Customizing Salesforce with Lightning Aura Components Series

This will be the third of a series of posts I will be doing over the next few weeks. This particular post will cover working with Salesforce Data. The series will all lead up to the introduction of my new course titled, “Customizing Salesforce with Lightning Aura Components” from Pluralsight. This course is a total re-write of my most popular course, “Customizing Salesforce with Lightning Components: Getting Started“, which was released back in 2017. It will focus on using the new modern toolset that Salesforce offers as part of Salesforce DX.

Working with Controllers

In the last post, I walked you through creating the updateCellNumber Aura component in Visual Studio Code. I also stepped you through how to add a design file so that the placeholder value was easily modifiable in Lightning App Builder.

So far this component will only show a windows alert when the submit button is pressed. I am going to show you how to change that and have it update the Salesforce database instead.

Lightning Components have two ways of dealing with Salesforce data:

1. Using the Lightning Data Service
2. Using Apex

In this post, I will only covering the second method of using Apex to write server-side code.

Working with Apex and DML

Apex is strongly-typed object-oriented proprietary language developed by Salesforce. Since Salesforce is a multi-tenanted environment, Apex is subject to limits.

DML or Data Manipulation Language is what Salesforce uses to insert, update or delete a Salesforce record. To change the updateCellNumber component so that it writes to the Salesforce database, I will need to add a Class that uses both Apex and DML. The class will be named updateCellNumberApex (so that it is not named the same as the client-side JavaScript controller). Any server-side methods used by Lightning components must have the @AuraEnabled annotation. They also must be public and static. The code for the class will be as follows:

public with sharing class updateCellNumberApex {
    @AuraEnabled()
    public static void CellNumberUpdate(String cellNumber) {
        List<User> users = [SELECT MobilePhone FROM User where 
                            Id =: UserInfo.getUserId()];
        
        if ( users.size() > 0 ) {
            users[0].MobilePhone = cellNumber;
            update users;
        }
    }
}

This code also uses a SOQL or Structured Object Query Language statement to select the MobilePhone number for the logged in user.

Once the class has been added, I will need to modify the component markup for updateCellNumber so that it is linked to this class. I do that by adding the following attribute to the aura:component tag, like this:

<aura:component controller="UpdateCellNumberApex"....

I will then need to switch to the client-side JavaScript controller and start by removing the code that produced a windows alert and replace it with the following:

var cellNumber = cmp.find("phone").get("v.value");
var action = cmp.get("c.CellNumberUpdate");
action.setParams({ "cellNumber" : cellNumber });
action.setCallback(this, function(response) {
    var state = response.getState();
    if (state === "SUCCESS") {
         alert(state);
     }
});
$A.enqueueAction(action);

Creating a New Open Cases Component

This component will display a list of open cases and will be named openCases. The final component will look like the following:

This Aura component will utilize the lightning:datatable base lightning component. Here is the code for the component markup:

<aura:component controller="getOpenCasesApex" implements="force:appHostable,flexipage:availableForAllPageTypes" access="global">
    <!-- attributes -->
    <aura:attribute name="caseList" type="Object"/>
    <aura:attribute name="columns" type="List"/>
    <aura:attribute name="numRecords" type="Integer" default="10" />

    <!-- handlers-->
    <aura:handler name="init" value="{! this }" action="{! c.init }"/>

    <lightning:card title="Open Cases">
        <lightning:datatable
                keyField="id"
                data="{! v.caseList }"
                columns="{! v.columns }"
                hideCheckboxColumn="true"/>
    </lightning:card>

</aura:component>	

And here is the JavaScript for the client-side controller:

({
    init : function(cmp, event, helper) {
        var numRecords = cmp.get("v.numRecords")

        cmp.set('v.columns', [
            {label: 'Subject', fieldName: 'linkName', type: 'url',
                typeAttributes: {label: {fieldName: 'Subject'}, target: '_self'}},
            {label: 'Type', fieldName: 'Type', type: 'text'},
            {label: 'Reason', fieldName: 'Reason', type: 'text'},
            {label: 'Status', fieldName: 'Status', type: 'text'},
        ]);

        var action = cmp.get("c.getOpenCases");
        action.setParams({"numRecords" : numRecords });
        action.setCallback(this, function(response) {
            var state = response.getState();
            if (state === "SUCCESS") {
                var records = response.getReturnValue();
                records.forEach(function(record){
                    record.linkName = '/' + record.Id;
                });
                cmp.set('v.caseList', records)
            }
        });
        $A.enqueueAction(action);
    }

})

The first part of this code is used to define the columns that will be used in the datatable. Notice that the first one is of the type url and that it has an additional definition for the typeAttributes. This is because this column will not only display the case subject, but will include a link to the case detail record.

The callback function will get whatever records are returned and then loop through those records and set the linkName so that it references the Cases record Id.

This component will utilize an Apex controller named getOpenCasesApex. It includes code needed to check for the appropriate FLS and CRUD level security. It also includes cacheable=true for the @AuraEnabled annotation in order to take advantage of caching for performance.

public with sharing class getOpenCasesApex {
    @AuraEnabled(cacheable=true)
    public static List<Case> getOpenCases(Integer numRecords) {
        // Code needed to check for proper access
        String [] caseFields = new String[] {'Id','Type','Reason','Subject','Status'};

        Map<String,Schema.SObjectField> caseMap = Schema.SObjectType.Case.fields.getMap();
        for (String fieldToCheck : caseFields) {
            if( !caseMap.get(fieldToCheck).getDescribe().isAccessible()) {
                throw new System.NoAccessException();
            }
        }

        List<Case> caseList = [SELECT Id,Type,Reason,Subject,Status FROM Case
        WHERE IsClosed = false
        LIMIT : numRecords];

        return caseList;
    }

}

And finally, it includes a numRecords input parameter, which is passed in form the value set when the component is configured in Lightning App Builder. The associated design file for this component is as follows:

<design:component label="Configurable Open Cases Component">
    <design:Attribute name="numRecords" label="Number of Records Returned" placeholder="10" />
</design:component>

In the next post, I will go over how to design components that do not require an Apex controller.