How to Call Apex Class From Salesforce Flow

Sometimes, automating the process using Salesforce flow can be limited by the capabilities for handling complex logic. So, for that, we can use an apex class to automate the process and then call an apex class from a flow.

In this Salesforce tutorial, we will learn how to call an Apex class from Salesforce flow. In this, I will explain what an invocable method is; then, we will create an Apex class and call that Apex class in the flow.

Table of Contents

What is the Invocable Method in Salesforce?

To call Apex code from a flow, we need to create an Invocable method within the Apex class. This method is annotated with @InvocableMethod, which makes it accessible to the flow.

The label attribute in the annotation specifies the display name of the Apex Action. Each class can contain only one Invocable Method and accept a single parameter.

There are some considerations to keep in mind when declaring the invocable method in the Apex class.

Class Visibility: The Apex class must be defined as public or global. So that it can be accessible from the flows.
Method Visibility: The Invocable method must be static and public or global.
Class Type: The class must be an outer class.
Invocable Method Limit: There can be only one Invocable method per class.

Example: Call Apex Class From Salesforce Flow

In the following step, I will explain how to call the Apex class in Salesforce flows. For that, first, we need to create an apex class with an invocable method.

Create Apex Class with @InvocableMethod

Now, we will create a class where we can implement the complex logic that cannot be implemented by a flow. After creating the class, we will call the apex class from the Salesforce flow.

Let’s take a scenario: When an opportunity is created from the account record page, the account’s site field in the account details will be updated with the website value entered in the opportunity object.

Here, we created an Apex class with the @invocableMethod annotation so that we can access this class in the flow.

public class CallApexByFlow {
    
    @InvocableMethod
    public static List<String> updateAccountSite(List<Id> ids) {
        List<Opportunity> oppList = [SELECT AccountId, Website__c FROM Opportunity WHERE Id IN :ids];

        Set<Id> accountIds = new Set<Id>();
        for (Opportunity opp : oppList) {
            if (opp.AccountId != null) {
                accountIds.add(opp.AccountId);
            }
        }

        Map<Id, Account> accountMap = new Map<Id, Account>(
            [SELECT Id, Site FROM Account WHERE Id IN :accountIds]
        );

        List<String> accountSites = new List<String>();
        List<Account> accountsToUpdate = new List<Account>();

        for (Opportunity opp : oppList) {
            if (accountMap.containsKey(opp.AccountId)) {
                Account acc = accountMap.get(opp.AccountId);

                if (String.isEmpty(acc.Site)) {
                    acc.Site = opp.Website__c;
                } else {
                    acc.Site += ', ' + opp.Website__c;
                }

                accountSites.add(acc.Site);
                accountsToUpdate.add(acc);
            }
        }

        if (!accountsToUpdate.isEmpty()) {
            update accountsToUpdate;
        }

        return accountSites;
    }
}

Configure Class in the Flow

In the steps below, I will explain how to create a flow and call an Apex class to automate the process.

1. Create Screen Flow

Go to Setup -> Flows -> New Flow -> Start From Scratch -> Screen Flow.

Add the Screen Element into the flow builder by clicking on (+) Add Element and configure the screen properties by using the API name and label.

Drag the following input from the component section into the screen canvas:

Components	Lable
Text	Opportunity Name
Date	Close Date
Picklist	Stage Name
Text	Website

2. Create Variables in Flow

recordId: This variable is used to store the Account Record ID. When the flow is triggered from an account record page(for example, when a user creates the opportunity record), the current account’s ID is passed into this variable.

OpportunityId: This variable is used to store the opportunity ID after the opportunity record is created within the flow. It is initially empty and will be populated with the ID of the newly created opportunity once the flow executes the “Create Record” action.

3. Create Opportunity Record

Add the ‘Create Record’ element onto the canvas and provide the Label and API name. Select “Opportunity” as the object to create. Set the field values for the opportunity.

Field(Opportunity)	Value(Screen Component)
AccountId	{!recordId} (created Variable)
CloseDate	{!Close_Date}
StageName	{!StageName}
Name	{!Opportunity_Name}
Website	{!Opportunity_Website}

Create Record Element in Salesforce Flow

We also need to store the created opportunity ID into a variable that we created for that. Check the box for ‘Manually assign variables‘. Provide a Variable to store OpportunityId and click Done.

4. Add Action Element

Now, after creating the opportunity record, we need to call the apex class, where we implemented logic for updating the account site.

Add an Action element onto the canvas.
In the Search box, search for the Call Apex By Flow.

Provide a Label and API Name for the action.
In the Set Input Values for the Selected Action, add the OpportunityId variable where we have newly created opportunity ID– {!OpportunityId}.

Then click the Show Advanced Options dropdown.

Now, first, we need to create a variable to store the values that we will be getting from the action, which is the apex class. Here, I created a Text variable named ActionValue.

Now, check the checkbox Manually assign variables from the advanced option. Then, in the Store Output Values, select the created text variable(ActionValue).

Create Salesforce Flow to Call Apex Class

Now, after executing the action element, the link will get into the created variable, and that link will be displayed in the screen element using the Display Text component. So here I added text and the variable in which we have the output value.

After that, click the Done button and save the flow.

For this flow, I provided the ‘Call Apex From Salesforce Flow‘ name and saved the flow. After that, I Activated the flow, and only then can we add screen flow to the record page.

5. Add Screen Flow to Account Record Page

Now, we need to add the created screen flow to the account record page. For that, navigate to the Account object tab and open any record. Click the Gare icon -> Edit Page -> the Account Record Page will open.

To add the flow, in the Component, search for Flow, drag and drop where you want on the record page. In the flow, select the flow label that you provided.

Then, in the OpportunityId field, check the pass record ID into the variable, and the field will automatically take the ID, and the same is true for the recordId variable.

Finally, save the changes and activate the record page.

Output

In the image below, you can see that I have opened an account record in which the Account Site field is blank.

Also, that account only has two related opportunities. Now, I have provided value to the screen flow that we added on the account record page to create an opportunity record. After providing value, click the Next button.

Create Opportunity Record Using Screen Flow

As you click the next button, the opportunity record will get created, and the Action element will also call the Apex class, where we implemented logic to assign the website field value (opportunity) to the Account Site file(account).

Here, you can see, using the display text component, we displayed the Account Website Link, which was provided in the opportunity creation.

Apex Class To create Record in Salesforce

Also, the opportunity that we created is related to the account object.

Create Related Record Using Salesforce Flow

As you open the account details, you will see the Account Site, the same as we provided on the opportunity website.

In this way, we can call the apex class from Salesforce flows. In the Apex class, we can implement complex logic that cannot be created using flow, and then use the flow to call the Apex class.

Conclusion

I hope you have an idea how to call the Apex class from Salesforce flow. In that, I have explained what an invocable method is; then, we created an apex class where we implemented logic to update the accounting field and then called that apex class by using flow.