Introducing the Prefetch Block

The prefetch block must be the first entry in the action script (other than comments or blank lines). It contains all the download prefetch logic needed to prepare for subsequent action execution, making the action easier to understand. Some of the methods that can be used in a prefetch block include:

Literal downloads

These are ordinary static downloads, which are still available.

Conditional downloads

Only those commands inside TRUE condition pathways are performed.

Variable Substitution

This includes downloads that use relevance substitution to determine which files to collect.

Custom logic

This takes advantage of a plug-in to create download manifests.

Unlike the pre-parsing algorithm used in the traditional downloading actions, prefetch block downloads can be viewed as a top-down approach: the prefetch block comes first and must successfully complete before the rest of the action can continue. This provides greater control, flexibility and power.