@InvocableMethod Annotation

I’m using the @InvocableMethod annotation in my Apex class to allow a Flow to update accounts, but I’m encountering an issue when trying to pass multiple input parameters. Salesforce is throwing an error saying, “Methods defined with @InvocableMethod must have a single parameter of type List.” How can I structure my method to accept multiple parameters, such as account names and industries, while adhering to the @InvocableMethod constraints? Here’s the code I’m working with during my Salesforce training in India, which isn’t functioning as expected:

Code:

---

public with sharing class AccountUpdater {
    @InvocableMethod
    public static void updateAccounts(String accountName, String accountIndustry) { // Error: Multiple parameters not allowed
        List<Account> accountsToUpdate = [SELECT Id FROM Account WHERE Name = :accountName];
        for (Account acc : accountsToUpdate) {
            acc.Industry = accountIndustry;
        }
        update accountsToUpdate;
    }
}

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How can I modify this code to meet the requirements of the @InvocableMethod annotation?

To resolve the issue and adhere to the constraints of the @InvocableMethod annotation, which requires a single parameter of type List, you need to encapsulate the input parameters (accountName and accountIndustry) into a custom class. This custom class can then be passed as a single List parameter to the updateAccounts method.

Here’s how you can modify your code:

Solution: Use a Wrapper Class for Input Parameters

Code:

---

public with sharing class AccountUpdater {
    // Wrapper class to encapsulate input parameters
    public class AccountUpdateRequest {
        @InvocableVariable(required = true)
        public String accountName; // Name of the Account
        @InvocableVariable(required = true)
        public String accountIndustry; // New Industry for the Account
    }

    @InvocableMethod
    public static void updateAccounts(List<AccountUpdateRequest> requests) {
        // Collect account names from the requests
        Map<String, String> nameToIndustryMap = new Map<String, String>();
        for (AccountUpdateRequest request : requests) {
            nameToIndustryMap.put(request.accountName, request.accountIndustry);
        }

        // Query Accounts based on provided names
        List<Account> accountsToUpdate = [SELECT Id, Name FROM Account WHERE Name IN :nameToIndustryMap.keySet()];
       
        // Update the Industry field for the queried Accounts
        for (Account acc : accountsToUpdate) {
            acc.Industry = nameToIndustryMap.get(acc.Name);
        }
       
        // Perform the DML update
        if (!accountsToUpdate.isEmpty()) {
            update accountsToUpdate;
        }
    }
}

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Explanation

1. Wrapper Class:

A public class AccountUpdateRequest is defined to hold the two input parameters (accountName and accountIndustry).

The @InvocableVariable annotation is used to make the variables accessible to Salesforce Flow or Process Builder.



2. Method Signature:

The updateAccounts method now accepts a single List parameter of type AccountUpdateRequest, satisfying the constraints of the @InvocableMethod annotation.



3. Processing the Input:

The method iterates through the list of requests, creating a mapping of account names to industries.

Accounts are queried based on the names provided in the requests.



4. Updating Accounts:

The industry of each account is updated based on the mapping, and then all updates are applied in a single DML statement.




How to Use in Flow

In the Flow, you can create a collection variable where each element is an instance of the AccountUpdateRequest class.

Pass this collection to the updateAccounts method.


This structure ensures that your method is compatible with the @InvocableMethod constraints while supporting multiple input parameters.