bcquality/microsoft/knowledge/data-modeling/dimension-management-wiring.md
Michael Dieringer a28ba1a1d7 Address second round of Jesper Schulz-Wedde's review on PR #156
- dimension-management-wiring.md/.good.al: split into the two distinct
  models the article was conflating - master data (Default Dimension
  records via ValidateDimValueCode/SaveDefaultDim) vs. transactional/
  document data (a single Dimension Set ID assembled via AddDimSource +
  GetDefaultDimID, verified against BCApps' ExchRateAdjmtProcess.Codeunit.al).
  Added a compiling document-table example alongside the existing master
  table one.
- Deleted api-page-flowfields-must-be-calcfields (.md/.good.al/.bad.al):
  Microsoft's own FlowFields documentation states a FlowField used as a
  control's direct source expression is automatically calculated on any
  page - no API-page exception is documented, and none could be
  reproduced.
- prefer-email-module.bad.al/.md: Codeunit Mail has no Send/GetErrorDesc
  members; fixed to the real current 7-argument CreateMessage signature,
  and corrected the claim that the legacy path "still runs" - its base
  implementation no longer sends anything, only raises integration events.
- check-post-line-batch-pattern.md/.good.al: reframed from a universal
  invariant to the standard shape, naming the real Gen./Item/CA/Res./Job/
  Insurance/Mfg. Item/FA Jnl.-Check Line/-Post Line/-Post Batch codeunits
  it's based on. Added the missing Check Line companion codeunit so the
  good fixture is internally complete.
- test-data-must-be-random-and-complete.good.al: removed leftover
  "collision-free" wording contradicting the already-corrected article text.
- fixed-choice-set-must-use-enum-not-integer.md: removed the reintroduced
  state-count heuristic ("the line is the state count"), aligned with
  binary-choice-must-be-boolean.md's semantics-based distinction.
- namespace-must-be-verified-from-source.md: removed the false claim that
  the compiler and AL Language Server use different namespace-resolution
  rules.
- intrinsic-al-functions-must-use-modern-casing.md: removed the unverified
  claim that PascalCase is the VS Code formatter's default output.

Worklist completeness: added cues for the 8 rules in data-modeling,
testing, performance, and web-services that had none (Jesper's explicit
ask), plus the same gap in all 7 style rules from this PR (not explicitly
named this round, but the identical systemic issue) - 15 cues total across
al-data-modeling-review.md, al-testing-review.md, al-performance-review.md,
al-web-services-review.md, and al-style-review.md.

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-09-21 22:26:33 +02:00

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3.2 KiB
Markdown

---
bc-version: [all]
domain: data-modeling
keywords: [dimensions, dimensionmanagement, global-dimension, shortcut-dimension, default-dimension, validatedimvaluecode, getdefaultdimid]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Wire dimension support through DimensionManagement, not ad hoc fields
> Contributions welcome — open a PR to refine or extend this article.
## Description
Adding dimension support to a custom table is not just a matter of adding a `Code[20]` field, and master tables and document/transactional tables wire into `Codeunit "Dimension Management"` through two different models — treating them as one mechanism is itself the mistake this article corrects:
- **Master data** (a custom master table, e.g. "Course") persists **Default Dimension** records: each shortcut dimension field validates through `ValidateDimValueCode`, then the result is saved via `SaveDefaultDim`, and `DeleteDefaultDim` removes them again in `OnDelete`. The master record itself carries no `Dimension Set ID` field.
- **Transactional/document data** (a custom document or journal-line table) carries a single **`Dimension Set ID`** field — a pointer to a shared, deduplicated set of dimension values in `Dimension Set Entry`, assembled from whatever the document inherited plus whatever the user overrode. A document does not acquire that ID by calling `SaveDefaultDim`; it builds a source list with `AddDimSource` (naming the related master table and its key, e.g. `Database::Customer`), then calls `GetDefaultDimID` to compute a new `Dimension Set ID` that inherits the master's Default Dimension records. Editing a shortcut dimension field directly on the document validates through `ValidateShortcutDimValues`, which updates the same `Dimension Set ID` in place rather than writing a separate Default Dimension record.
Skipping the model that actually matches the table's kind produces a field that looks correct in the designer but silently fails to save, validate, or carry through to postings — or, for a document, one that never picks up the customer's/vendor's own dimensions at all.
## Best Practice
For a master table, validate each shortcut dimension field through `ValidateDimValueCode`, save the result with `SaveDefaultDim`, and delete the matching Default Dimension records in `OnDelete`.
For a document table, when the field that attaches the document to a master record changes (e.g. `Customer No.`), call `AddDimSource` naming that master table and key, then `GetDefaultDimID` to compute the document's new `Dimension Set ID`, inheriting the master's Default Dimension records. Validate the document's own Shortcut Dimension fields through `ValidateShortcutDimValues`, which updates that same `Dimension Set ID` rather than persisting a separate Default Dimension record.
See sample: `dimension-management-wiring.good.al`.
## Anti Pattern
Adding a dimension-looking field with only a `TableRelation` to Dimension Value, and no call into `DimensionManagement` at all. The field accepts input but never becomes a real Default Dimension record, so it does not validate against blocked values and does not flow into postings.
See sample: `dimension-management-wiring.bad.al`.