This is the third article in a series of articles about the Batch API in Drupal. The Batch API is a system in Drupal that allows data to be processed in small chunks in order to prevent timeout errors or memory problems.
So far in this series we have looked at creating a batch process using a form and then creating a batch class so that batches can be run through Drush. Both of these examples used the Batch API to run a set number of items through a set number of process function callbacks. When setting up the batch run we created a list of items that we wanted to process and then split this list up into chunks, each chunk being sent to a batch process callback.
There is another way to set up the Batch API that will run the same number of operations without defining how many times we want to run them first. This is possible by using the "finished" setting in the batch context.
Let's create a batch process that we can run and control using the finished setting.
Setting Up
First we need to create a batch process that will accept the array we want to process. This is the same array as we have processed in the last two articles, but in this case we are passing the entire array to a single callback via the addOperation() method of the BatchBuilder class.