Thoughts on agile software development
“Those who know nothing of foreign languages know nothing of their own.” Johann Wolfgang von Goethe Internationalization, or I18N for short, is a skill that every modern software must master. Long gone are the days when software could only offer an English only interface. Localizable values such as dates and numbers can always be output … Read more
In the last article on FreshMarker Ranges, the Right-limited Exclusive Ranges and Length-limited Ranges were introduced. They were not part of the FreshMarker Ranges support for quite some time. Previously, it was only possible to create regular ranges with the Length-limited Ranges syntax, i.e. ranges that represent monotonically increasing sequences. The reason is simply illustrated … Read more
One of the fundamental design decisions for FreshMarker is always the question of whether a feature is actually needed or whether pre-processing the data can solve the problem. This is always a delicate balancing act, because any unnecessary pre-processing casts a shadow on the attractiveness of the template engine. It’s always a question of whether … Read more
In a Reddit forum, a suggestion was made to support template fragments in FreshMarker. Template fragments are parts of a template that can be used individually. The question that naturally arises is why would you want to use parts of a template individually? After all, many template engines offer the option of construct a template from different sources using include instructions. Such an include can then also be used individually.
FreshMarker as a Template Engine supports a whole range of data types for its model values. This data type are usually a mapping of the corresponding Java types such as String, Boolean, Long, Beans, Records, List and Maps. In addition, FreshMarker has the data type Range, which describes intervals with a lower and an optional upper limit.
In the previous article on operator overloading, the implementation for the numerical addition and multiplication operators was presented. In this article, some other operators will be provided with this feature and some details will be discussed that should be taken into account when operator overloading.
Operator overloading is a programming technique in which an existing operator is extended or adapted to user-defined data types. This makes it possible to design user-defined classes in such a way that they behave syntactically like built-in data types and facilitates intuitive and readable use of these types using the familiar operators. This article presents the integration of operator overloading in FreshMarker.
Sometimes a new feature also needs to be a bit of fun. When updating the FreshMarker Grammar, I noticed that the operators lt, gt, gte and lte were still present. These are variants of the usual <, >, <= and >= operators and are reminiscent of the opcodes of a long-forgotten era when assembler languages still roamed the steppes of programming. Since FreshMarker was given its Unicode capabilities by CongoCC, the question arose as to why not allow ≠ and other operator characters in the template.
It will come as no surprise that FreshMarker, like all other template engines, must take precautions against template injection. Template injection is a security vulnerability that occurs when an application handles templates insecurely. Templates are prefabricated files or strings with placeholders that are replaced by data from users or other sources. Similar to FreeMarker, FreshMarker also has an escape mechanism that detects special characters in the interpolations using a harmless variant. If the standard mechanism is not enough, OWASP can help out.
In the first article on FreshMarker performance, some of the template engine’s speed problems were addressed. The benchmark showed a tripling of the speed for these adjustments. In this article, the use of Reflections will be removed, which is certainly also of interest outside of a template engine.