OP-HAS-FORM-FIELDS: Has form fields

Reports whether a submitted PDF contains form fields, using the caller-selected inspection client.

Field	Value
Operation ID	OP-HAS-FORM-FIELDS
Trigger	Client submits POST v1/info/fields/exist with PDF bytes
Entry endpoint	POST v1/info/fields/exist
Owning component	InfoController.HasFormFields(byte[], bool) → PdfClientService.HasFormFields | PdfHelper (Syncfusion)
Inputs	Request body: byte[] PDF; query: useClient (default true)
Outputs	Bare bool
Failure response	No try/catch on this action — any exception produces framework exception detail (IncludeErrorDetailPolicy.Always) before ApiResponseHandler runs; the final client-visible envelope is unknown** (see Endpoints: Error response shape)

Steps

1. useClient (default true) selects the inspection implementation (BR-PDFAPI-021):
2. true (default): PdfClientService.HasFormFields (iTextSharp) is invoked, which first validates the %PDF- signature (BR-PDFAPI-005).
3. false: PdfHelper.HasFormFields (Syncfusion) is invoked instead.

PdfClientService.HasFormFields is implemented in PdfAPI.Core, documented in full at Detect form fields (OP-06). PdfHelper.HasFormFields is implemented in PdfApi.SyncFusionCore, documented in full at Inspect and flatten PDF form fields (OP-SFC-013). Both behaviors are summarized here only as observed on this request path.

Origin: The useClient = true detection behavior in this step is implemented in PdfAPI.Core; the useClient = false detection behavior is implemented in PdfApi.SyncFusionCore. See the linked operation pages for the full delegated logic. 2. On the useClient = true path, a non-PDF payload raises PdfException, which escapes uncaught to the framework, producing exception detail before ApiResponseHandler runs; the final client-visible envelope is unknown**. 3. The bare bool result is returned — HTTP 200.

Process flow

The following diagram shows the client-selection and validation sequence for the form-fields existence check.

flowchart TD
    A["POST v1/info/fields/exist"] --> B{"useClient?"}
    B -->|true default| C["PdfClientService.HasFormFields: iTextSharp"]
    B -->|false| D["PdfHelper.HasFormFields: Syncfusion"]
    C --> E{"Valid PDF?"}
    E -->|No| F["PdfException escapes to framework: 500"]
    E -->|Yes| G["Return bool, 200"]
    D --> G

Transaction and side effects

Aspect	Finding
Unit of work	None
Commit point	Not applicable — no database access
Records written	None
Downstream calls	None
Repeat-call behavior	Read-only; safe to repeat

Logging

Surface	Written content
—	No dedicated logging observed on this path beyond framework-level exception logging on an uncaught failure

Error handling

• Non-PDF payload on the useClient = true path: PdfException escapes uncaught, producing framework exception detail before ApiResponseHandler runs; the final client-visible envelope is unknown** (BR-PDFAPI-005; see Endpoints: Error response shape).

Related documentation

• API index
• Overview
• Architecture
• Endpoints
• Authentication and authorization
• Dependencies
• Configuration
• Operations and processes
• Business rules
• Data model
• Operational runbook
• Tech debt

Note: Statements marked with ** could not be confirmed; treat as unknown until verified.

Sources

• PdfAPI\Controllers\v1\InfoController.cs
• PdfAPI.Core\Services\PdfClientService.cs
• PdfApi.SyncFusionCore\PdfHelper.cs