Edge Cases & Limits

How ZeroExport behaves at the edges — missing data, malformed rules, limits, and formatting fallbacks — so generated documents stay predictable.

ZeroExport is built to fail safe and stay predictable: missing data renders empty rather than breaking, malformed rules hide content rather than leaking it, and every value has a defined fallback. This page is the reference for that behavior.

Merge field edge cases

Situation	Behavior
Field is empty / blank	Renders as empty text — no `{{...}}` braces printed
Alias or field not in the template's data sources	Rejected on save with an error naming the token and the field to add
Token names a data source with no field (`{{Contacts}}`, `{{Account}}`)	Rejected on save; in an older saved template it prints nothing
Related record is missing (`{{A.B.C}}` where B is null)	Renders empty
Unknown system variable (e.g. `{todya}`)	Rejected on save, listing the valid names
Unclosed or unmatched braces (`{{Field`, `Field}}`, `{toda`)	Rejected on save
Merge syntax needed as plain text	Escape each brace with a backslash: `\{\{Field\}\}` prints `{{Field}}`
Field name casing differs	Matched case-insensitively — `{{account.name}}` = `{{Account.Name}}`

Iteration edge cases

Situation	Behavior
Parent has no child records	Repeating rows/items produce no output (no empty row)
Table grouped by a list with no rows	Prints its header rows only
Need a "no records" message	Add a separate element with a visibility rule for the empty case
Builder preview row count	Child collections are capped in preview for speed; full data renders on generation
List nesting depth	Nested lists are limited to 3 levels deep

Conditional visibility edge cases

Visibility is fail-closed — when in doubt, the element is hidden:

Situation	Result
Rule references a missing field	Element hidden
Condition has no rows	Element hidden
Rule is malformed / errors during evaluation	Element hidden
A shared condition references an ID that no longer exists	Element hidden
Ordering comparison (`>`, `<`, `>=`, `<=`) on non-numeric values	Condition is false (fail-closed)
Checkbox field with an operator other than `=` / `!=`	Condition is false

Limits

Limit	Value
Conditions per visibility rule	10
Parenthesis nesting in custom logic	5 levels

Exceeding either limit hides the element rather than partially evaluating.

Null and empty handling

Is Null treats a truly empty compound field (Address / Geolocation with all sub-fields blank) as empty.
Explicit = or != against an empty field still evaluates deterministically (e.g. Field = is true when the field is blank).

Formatting fallbacks

Case	Behavior
Date with no format spec	Rendered in the running user's locale
Datetime with no time zone	Converted to the running user's time zone
Date-only field with a time zone in the spec	Time zone ignored — the date never shifts across zones
Number with no spec	Locale-aware grouping separators
Percent field (`0–100`)	`%` appended without re-scaling
Currency in a multi-currency org	Uses the record's own currency symbol, not the user's default
Unsupported currency glyph	Substituted with a PDF-safe form (e.g. INR → `Rs.` , THB → `THB` ) so it never renders as a blank box
Checkbox / Boolean value	Rendered as `[X]` (true) or `[ ]` (false)
Multi-select picklist	Semicolons become commas: `Red;Blue` → `Red, Blue`
Compound Address	Rendered multi-line, blank parts omitted

Large records and debug logs

A record with thousands of child rows is queued instead of generated in the calling transaction when its fetched rows are not expected to fit in the CPU time left (about 3 ms of Apex CPU per row). An active debug log makes Apex take about 2.5 times the CPU, which Apex cannot detect, so test large documents with debug logs off.

PDF rendering constraints

The PDF engine supports a focused subset of CSS. Keep these in mind when styling:

Not supported: JavaScript, external stylesheets, CSS classes (inline styles only), flexbox/grid, advanced selectors, and pseudo-elements.
Some currency and script glyphs are missing from default PDF fonts — ZeroExport already substitutes PDF-safe currency symbols for you (see above).
Preview in HTML first to catch layout issues quickly, then confirm in PDF.