eForms SDK 2.0.0
| This is a pre-release version of this document. The eForms SDK 2.0.0 is still under development. This notice will be removed when the document is finalized. |
Objective
The goal of SDK 2 is to introduce a new version of EFX (the eForms Expression Language) that:
-
enhances the template definition vocabulary to allow more accurate and user-friendly notice visualisation that is easier to maintain and share,
-
improves the ability of the language to express business rules with completeness and simplicity, enabling porting of validation rules to engines other than Schematron and supporting live validation on different target platforms,
-
enhances the language in ways that improve its expressiveness and readability, making it easier to write, read, maintain and interpret.
What’s new
EFX-2 has two distinct language flavors — EFX Templates and EFX Rules — both built on the shared EFX Expressions syntax which they extend for their specific applications.
EFX Expressions
The shared expression syntax has been enhanced with:
-
WITH ... COMPUTEsyntax: Expressions can now be written asWITH context COMPUTE expression, improving readability over the EFX-1 syntax. -
Improved type safety: The grammar enforces a stricter distinction between scalar and sequence types. Ambiguities in late-binding have been removed, and variables and parameters can now be declared with sequence types.
-
Working with sequences: Sequence literal syntax now uses
[…]instead of(…). New conditions allow testing sequences directly (is empty,has duplicates,is unique). Iterations support aDISTINCTmodifier and can return sequences for concatenation. -
New built-in functions for working with numbers, strings, dates/times/durations, sequences, and type conversions.
-
Field properties: Access to privacy-related properties of fields withheld from publication, linked field properties, and raw value access.
-
Node presence testing: Presence conditions can now be applied to node references in addition to field references.
-
The
measuretype has been renamed todurationto free the keyword for other types of measure. Duration functions have been renamed accordingly.
EFX Templates
The template language has been enhanced in three areas:
-
Template syntax and logic: Template lines now use
WITH context DISPLAY template;syntax with optional context and conditional rendering (WHEN/OTHERWISE). Navigation and Summary sections provide better structure for view templates. -
Reuse and maintainability: Callable templates, user-defined functions, and dictionaries reduce duplication and improve performance.
-
Richer output: Hyperlink blocks, character references, escape sequences, and locale-aware formatting functions.
EFX Rules
EFX-2 introduces a complete rules language, allowing business rules to be authored directly in EFX:
-
Rules file structure: Rules are organised into validation stages, with stage-level variables and include directives for composition.
-
Rule syntax: Rule-sets group multiple rules sharing the same context. Rules use
ASSERT(must be true to pass) orREPORT(triggers when true), with conditional branching, severity levels, notice type targeting, and scope annotations. -
Dynamic rules: API endpoint declarations and dynamic functions allow validation to consider information retrieved from other notices through a specialised API.
For details on what has changed in EFX 2, see the dedicated page on "What’s new in EFX 2".
SDK Metadata
SDK 2 focuses its breaking changes exclusively on the EFX language. The metadata file formats and directory layout remain the same as SDK 1, so that applications can migrate to SDK 2 without having to rewrite their metadata import logic. All EFX expressions embedded in SDK metadata use EFX-2 syntax.
SDK 2.0 will be released in alignment with SDK 1.15. With the exception of fields withheld from publication ("unpublished" fields) and dynamic rules, SDK 1.15 will have business equivalence with SDK 2.0, differing only in EFX expression syntax. SDK 1.15 will be the last version of the SDK 1.x series.
Forward-compatible metadata
SDK 2 also introduces forward-compatible metadata files in fwd/ subfolders. These new formats preview the structure planned for SDK 3 and are fully supported. Both backward-compatible and forward-compatible formats describe the same eForms metadata — a notice produced using either format is identical. This allows applications to gradually adopt the new formats during the lifetime of SDK 2. When SDK 3 is released, the backward-compatible files will be removed and replaced by the forward-compatible versions.
