bcquality/microsoft/knowledge/style/api-page-delayedinsert-true.md
Jesper Schulz-Wedde a9f3c50863 Regenerate microsoft/knowledge from upstream BCApps instructions
The previous LLM-generated knowledge files contained factual
hallucinations. The most visible was the claim that `FindFirst` /
`FindLast` "forces a full-table scan" on an unfiltered record - it does
not; those APIs return a single row via the current key.

Other inaccuracies the audit found and fixed:

* `FindSet(true)` was described as "taking a LockTable". The correct
  upstream phrasing is that `FindSet(true)` sets
  `ReadIsolation::UpdLock` on the read. UpdLock and LockTable are
  related but distinct mechanisms.
* The list of production-scale tables had been invented beyond the
  upstream source (e.g. "Detailed Cust. Ledg. Entry") without a
  citation. The regenerated list matches the ten tables upstream lists
  with their P95 row counts.
* `SetLoadFields` guidance had been augmented with an extra mechanism
  claim ("the database resolves the filter using the index without
  hydrating the value") not present in upstream.

Approach: full regeneration of `microsoft/knowledge/` from the six
upstream BCApps Code Review instruction files, with Microsoft Learn /
the AL language reference as a secondary source. Every claim in every
regenerated file is anchored to a verbatim upstream quote (or a Learn
URL); the audit trail lives in artifacts/trace-<domain>.json on the
session workspace.

The PR #11 transaction/error-handling cluster is preserved verbatim:

* performance/understand-implicit-transaction-boundary.md
* performance/codeunit-run-as-atomic-sub-operation.{md,good.al,bad.al}
* performance/codeunit-run-requires-prior-commit-inside-transaction.{md,good.al,bad.al}
* performance/use-tryfunction-for-error-catching-not-rollback.{md,good.al,bad.al}
* performance/avoid-commit-inside-loops.{md,good.al,bad.al}
* security/commitbehavior-attribute-scopes-explicit-commits.{md,good.al,bad.al}
* testing/transactionmodel-attribute-governs-test-transactions.{md,good.al,bad.al}

These articles already cite Microsoft Learn and were carefully
cross-referenced; the regeneration skips their topics rather than
duplicating them.

File counts after regeneration:

  performance   35 .md  (5 preserved + 30 new)
  privacy       17 .md
  security      18 .md  (1 preserved + 17 new)
  style         33 .md
  testing        1 .md  (preserved)
  ui            19 .md
  upgrade       18 .md

Total 141 atomic knowledge files, each strictly one rule. All pass
.github/scripts/validate_frontmatter.py with 0 errors and 0 warnings.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
2026-05-21 09:53:09 +02:00

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1.5 KiB
Markdown

---
bc-version: [all]
domain: style
keywords: [api-page, delayedinsert, insert-trigger, validation]
technologies: [al]
countries: [w1]
application-area: [all]
---
# Set `DelayedInsert = true` on API pages
## Description
On a normal page, `DelayedInsert = false` is the default: the record is inserted into the table as soon as the user enters the first field, and subsequent fields are written via `Modify` triggers. That model does not work for an API endpoint, where the consumer sends a complete JSON payload in a single request and expects exactly one `Insert` to fire with all fields already populated. `DelayedInsert = true` defers the insert until every field on the page has been assigned, so the `OnInsert` trigger runs once with the full record and `OnValidate` triggers on individual fields run in a predictable order. The convention is that API pages always set `DelayedInsert = true`.
## Best Practice
Declare `DelayedInsert = true` on every page with `PageType = API`. The setting plays well with `Modify(true)` and `Insert(true)` calls inside `OnInsert` and avoids the half-populated record states that otherwise reach validation logic.
See sample: `api-page-delayedinsert-true.good.al`.
## Anti Pattern
Omitting `DelayedInsert` (which defaults to `false`) on an API page. Validation triggers fire on a partially populated record, mandatory-field errors come back to the caller for fields the JSON payload was about to supply, and the API surface produces failures that have no analogue in the UI page model.
See sample: `api-page-delayedinsert-true.bad.al`.