Template Engine

When you write ${date + 3} in a template, TemplateLocalDate knows how to add an integer. When you write ${3 + date}, the roles are swapped: the number is on the left, and TemplateNumber has never heard of dates. Historically FreshMarker only dispatched operators on the left operand, which meant that a new type could never opt into being the right operand of an operator without patching every other type. This post walks through the design and implementation of the new symmetric operator dispatch that fixes exactly that.

FreshMarker has introduced the ~ operator, which concatenates values with a space. With FreshMarker 3.0.0, ~~ is introduced: the same concept, but this time non-textual primitives are passed through the configured formatter before concatenation—numbers, dates, and other primitives thus appear exactly as they do in the rest of the template. The Problem with Simple Concatenation FreshMarker has … Read more

Macro-based templates often need a sensible default body for the common case, while still allowing customization at the call site. FreshMarker 3.0.0 will support exactly that: <#nested/> can carry inline fallback content that renders automatically when no caller body is provided.

This article explains how the feature is implemented, from grammar to runtime, and includes a design note on one carefully chosen trade-off.

Memory management is a major challenge when it comes to improving the performance of Java applications. When many objects are created, memory must be allocated for them; these objects must be managed and eventually deleted, and their memory released. This comes at a cost, and an application that consistently works with fresh objects will suffer from reduced performance.

With Freshmarker 2.7.0, the PooledTemplateProcessor has been added, which guarantees a performance boost in template processing; however, this comes at the cost of compromises elsewhere.