Implementing Batch Apex Using Custom Iterables

Imagine having the power to effortlessly handle millions of records without hitting the governor limits or facing timeouts. Well, Batch Apex, a remarkable feature of Salesforce’s Apex programming language, makes this possible.

Batch Apex operates on the same principle as traditional batch processing in computer systems, breaking down hefty tasks into smaller, more manageable chunks. This allows you to process enormous volumes of data asynchronously, ensuring smooth execution without overwhelming system resources.

The beauty of Batch Apex lies in its ability to tackle the most demanding data processing tasks. By harnessing its capabilities, you can efficiently process massive data volumes that would otherwise cause timeouts or other issues in your Salesforce environment. Whether you’re working with extensive customer records, sales data, or any other dataset, Batch Apex becomes your trusted ally in swiftly and seamlessly managing the processing workload.

In this blogpost, you’ll learn about implementing Batch Apex using custom iterables.

But before we learn that, let’s first understand what custom iterables are.

Understanding Custom Iterables

Have you ever found yourself in a situation where you needed to traverse a collection of records in Salesforce but the standard iteration methods just didn’t cut it? Well, that’s where custom iterables come to the rescue!

In Salesforce, custom iterables provide developers with the power to iterate over records in a highly customized manner. They allow you to define a specific sequence for traversing records within a Salesforce object and give you the freedom to customize how these records are retrieved, sorted, and filtered.

To implement custom iterators, Salesforce provides Apex, its proprietary programming language. With Apex, developers can create custom iterable for any Object within the Salesforce platform. This means you have the flexibility to perform complex operations on collection of records such as applying specific filtering criteria, sorting based on particular fields, and even implementing custom logic to determine the order in which records are retrieved.

The possibilities offered by custom iterables are truly remarkable. They empower developers who work with large datasets or need to perform intricate calculations on collections of records. Whether you’re engaged in data analysis, business logic, or process automation, you can count on custom iterables.

Implementing custom iterables typically involves defining a class that implements two essential interfaces: Iterable and Iterator. The Iterable interface features a single method called iterator(), which returns an instance of the Iterator interface. The Iterator interface, on the other hand, encompasses three vital methods: hasNext(), next(), and remove(). The hasNext() method lets you check if there are more elements in the collection, next() retrieves the next element in the collection, and remove() allows you to remove the last element returned by the next() method.

Use Cases: When Should Batch Apex be Implemented with Iterables ?

The need for implementing Batch Apex using iterables arises when you have specific requirements that cannot be fulfilled by the traditional approach of using a query locator.

Here are some key reasons why you might choose to implement Batch Apex using iterables:

Additional Processing and Filtering: If you need to perform additional processing or apply custom filtering logic to the records returned by a query, implementing Batch Apex using iterables provides the necessary flexibility. With iterables, you have full control over the iteration logic, allowing you to easily incorporate custom processing or filtering logic into your batch operation. This enables you to modify records, perform complex calculations, or apply specific business rules during the iteration process.

Granular Control over Iteration: Using iterables in Batch Apex implementation allows you to define the sequence in which records are processed, providing granular control over the order of operations. This level of control is particularly valuable when you have specific dependencies or requirements that dictate the order in which records should be processed. By implementing your own custom iterable, you can ensure that the iteration occurs according to your specific needs.

Reusing Existing Lists or Collections: In scenarios where you already have a pre-existing list or collection of records that you want to process in batches, implementing Batch Apex using iterables can be highly efficient. Instead of executing a new query using a query locator, you can leverage the power of iterables to process the existing data structure directly. This approach eliminates the need to re-query the database and can significantly improve performance.

Complex Data Structures or External Data Sources: When working with complex data structures or integrating with external data sources, using iterables in Batch Apex allows you to handle the data in a customized way. By implementing your own iterable logic, you can traverse and process the data in a manner that aligns with the specific requirements of your application or integration. This is particularly valuable while dealing with hierarchical data structures, nested relationships, or external APIs.

How to Implement Batch Apex Using Custom Apex?

Let’s understand the steps with an example.

This is an example of a custom iterator with a batch class in Salesforce Apex that cannot be implemented with a query locator:

Implement the Custom Iterator:

• Create a class that implements the Iterable and Iterator interfaces.
• Define the Iterable interface’s iterator() method to return an instance of the Iterator interface.
• Implement the Iterator interface’s hasNext(), next(), and remove() methods as per your requirements.

Understand the Batch Class Integration:

• Create a CustomBatch class that implements the Database.Batchable interface as well as the Iterable and Iterator interfaces.
• Use the CustomBatch class’s constructor to receive an array of integers, which will serve as the basis for iteration.
• Implement the start() method to initialize the batch and return an instance of the CustomBatch class as an iterable.
• Use the execute() method to process the batch in chunks, iterating over the elements within the iterable.
• Leverage the finish() method for any post-batch processing tasks.

Utilize the Custom Iterator With a Batch Class:

• Instantiate an instance of the CustomBatch class, passing the required array of integers to its constructor.
• Invoke the Database.executeBatch() method, providing the CustomBatch instance as the parameter.

This will run the batch job in chunks of two elements and output the values 1, 2, 3, 4, and 5 to the debug log.

Final Takeaway

By following these steps, you can successfully implement Batch Apex using custom iterators. Take advantage of the flexibility and control they offer to efficiently process large datasets, perform complex operations, and unlock the full potential of your Salesforce records.

Start Optimizing Your Data Processing Today! Let’s Get Started.