Description
Check the supplied select placeholder-label-option conditions for a direct first empty-valued option; no DOM or validation state inference.
HTML form controls combine attribute values, option state and form-owner references with browser-maintained DOM state. These tools take explicit strings, lists and flags so a particular relationship can be checked in isolation. The supplied-record model does not itself inspect a document or reproduce every browser state transition.
Check the supplied select placeholder-label-option conditions for a direct first empty-valued option; no DOM or validation state inference.
When to use this tool
Use this tool to check the supplied select placeholder-label-option conditions for a direct first empty-valued option; no DOM or validation state inference.
How to use the tool and how it works
- Enter required, multiple, displaySize, optionValues, firstDirectChild using the field definitions below.
- Run the operation. Correct input errors before interpreting an output.
- Read result.placeholder. Use the ordering, boundary rules and absence conditions described below.
Return placeholder only when required is true, multiple is false, displaySize is one, the first option is a direct child and its supplied value is empty.1
| Input field | Meaning and units | Accepted input |
|---|---|---|
| required | Supplied required flag for the select. | A boolean true or false. |
| multiple | Supplied multiple-selection flag. | A boolean true or false. |
| displaySize | Supplied display size as an integer from 1 through 128. | A finite safe integer within the operation’s stated bounds. |
| optionValues | Supplied option values in option order. | Dense list of at most 128 strings, each at most 8,192 UTF-16 code units. |
| firstDirectChild | Whether the first option is a direct child of the select. | A boolean true or false. |
| Output field | Interpretation |
|---|---|
| result | Object containing the named fields below. |
| result.placeholder | Whether the supplied first option satisfies this placeholder-label condition. |
{
"input": {
"required": true,
"multiple": false,
"displaySize": 1,
"optionValues": [
"",
"x"
],
"firstDirectChild": true
},
"output": {
"result": {
"placeholder": true
}
}
}Limitations and assumptions
- The tool evaluates supplied facts without reading a DOM or checking the select’s complete validity state.
- All DOM-related facts are supplied by the caller. No element is queried, no browser state is mutated and no document-wide validity or accessibility audit is performed.
- Every declared top-level input field is required and unexpected fields are rejected. Ordinary strings are limited to 8,192 UTF-16 code units and lists to 128 entries, with tighter operation-specific bounds where stated. JSON text has bounded nesting and node counts.
- Numeric outputs must be finite and no larger in absolute magnitude than the safe-integer limit; operations returning exact large integers use decimal text. Positions are zero-based and spans end exclusively unless the operation explicitly states a different convention.
Alternative or Complementary methods
Use DOM inspection or browser constraint-validation APIs when actual document state matters. The supplied-record checks are useful for focused audits but do not replace a complete browser algorithm.
References
Similar or alternative tools
- HTML Option Selected State Reconciliation
Reconcile explicit option selected flags for a static single/multiple select; last selected wins in single mode and first defaults, excluding disabled-option and live-dirty-state behavior.
- HTML Form Associated Owner Reference
Resolve a supplied explicit form attribute before a supplied ancestor form; missing/duplicate owner evidence is retained, no DOM lookup or first-element claim.