ParseContext: Smarter Template Building with Build-Time Knowledge

by

FreshMarker has always optimised constant expressions during template parsing. The expression 2 + 3 becomes 5 before the first process(…​) call is ever made. That optimisation, however, had a hard boundary: anything involving the ~~ operator, registered formatters, or context-free built-ins was left untouched because the parser had no access to the configuration that governs them. This post describes the ParseContext, a new concept that hands build-time knowledge to the template builders and what that unlocks.

More Regular Expressions in FreshMarker

by

Every now and then, I look into the capabilities of other template engines for new features. If something offers added value and fits within FreshMarker’s concept, then it gets adapted. Sometimes the result is something completely different, and sometimes it’s very similar to the original. Since FreshMarker 2.3.0, the built-ins find, matches, and split have been available. Why not add a few new built-ins using regular expressions?

Symmetric operators in FreshMarker: reverse dispatch for X op Y

by

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.

REST endpoints with filters

by
Java Bibliotheken

This article is a slightly updated English version of the article “REST Endpunkte mit Filtern”.

In addition to sorting and pagination, filtering is a fairly common action on REST endpoints. In contrast to the first two, however, there is no adequate solution for filtering in the Spring Boot framework. With little effort, however, this can be elegantly implemented with the Spring Boot tools.

The ~~ Operator: Formatted Concatenation in FreshMarker

by

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

Phase 2: schema-aware typed compilation in FreshMarker

by

The previous post looked at the Stage 1 (untyped) compiler and finished with an honest observation: Stage 1 removes fragment-dispatch overhead but still evaluates every expression through TemplateObject. This third and final post explains how the Stage 2 compiler uses a TemplateTypeSchema to emit raw Java that talks directly to your data model — and how that unlocks the ~2.5× AOT speedup from the benchmark chart in the first post.

Nested Directives with Default Content

by

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.