THotPDF Loaded Form Field Methods

Syntax

function GetLoadedAcroForm: THPDFDictionaryObject;
function HasFormFields: Boolean;
function FormFieldExists(const FieldName: AnsiString): Boolean;
function GetFormFieldCount: Integer;
function GetFormFieldName(FieldIndex: Integer): AnsiString;
function GetFormFieldValue(FieldIndex: Integer): AnsiString; overload;
function GetFormFieldValue(const FieldName: AnsiString): AnsiString; overload;
function GetFormFieldType(FieldIndex: Integer): THPDFLoadedFormFieldType; overload;
function GetFormFieldType(const FieldName: AnsiString): THPDFLoadedFormFieldType; overload;
function GetFormFieldDescription(FieldIndex: Integer): AnsiString; overload;
function GetFormFieldDescription(const FieldName: AnsiString): AnsiString; overload;
function GetFormFieldOptionCount(FieldIndex: Integer): Integer; overload;
function GetFormFieldOptionCount(const FieldName: AnsiString): Integer; overload;
function GetFormFieldOptionValue(FieldIndex, OptionIndex: Integer): AnsiString; overload;
function GetFormFieldOptionValue(const FieldName: AnsiString; OptionIndex: Integer): AnsiString; overload;
function IsFormFieldReadOnly(FieldIndex: Integer): Boolean; overload;
function IsFormFieldReadOnly(const FieldName: AnsiString): Boolean; overload;
procedure SetFormFieldValue(FieldIndex: Integer; const Value: AnsiString); overload;
procedure SetFormFieldValue(const FieldName, Value: AnsiString); overload;
procedure SetFormFieldReadOnly(FieldIndex: Integer; ReadOnly: Boolean); overload;
procedure SetFormFieldReadOnly(const FieldName: AnsiString; ReadOnly: Boolean); overload;
procedure RenameFormField(FieldIndex: Integer; const NewName: AnsiString); overload;
procedure RenameFormField(const FieldName, NewName: AnsiString); overload;
procedure RemoveFormField(FieldIndex: Integer); overload;
procedure RemoveFormField(const FieldName: AnsiString); overload;
function RecalculateLoadedFormFields: Integer;
function FlattenLoadedFormFields(const FieldNames: array of AnsiString;
  EnforceSignaturePermissions: Boolean = True): Integer;
function FlattenFormFields: Integer;
procedure SaveLoadedDocument(const TargetFile: TFileName);

Description

These methods inspect and update AcroForm fields that already exist in a PDF loaded with LoadFromFile or BeginIncrementalUpdate. They support text fields (/FT /Tx), button fields (/FT /Btn), choice fields (/FT /Ch), signature fields (/FT /Sig), and unknown field types

GetLoadedAcroForm returns the resolved loaded /AcroForm dictionary for callers that need direct dictionary inspection before using the higher-level field methods

HasFormFields reports whether the loaded PDF or current in-progress document has AcroForm fields. FormFieldExists checks a loaded field tree or the authoring field list by field name without raising when the field is absent

GetFormFieldDescription reads the loaded field's /TU alternate field name, commonly used by PDF viewers as the field tooltip. It returns an empty string when the field has no description

GetFormFieldOptionCount and GetFormFieldOptionValue read the /Opt array on loaded choice fields. Simple string entries are returned directly; two-element option arrays return the first export value

IsFormFieldReadOnly reads bit 1 of the loaded field's /Ff flag. RenameFormField updates the loaded field's local /T name and rejects duplicate fully qualified names in the same loaded form tree

RecalculateLoadedFormFields visits the loaded /AcroForm /CO array in document order and evaluates the bounded AFSimple_Calculate operations SUM, AVG, PRD, MIN, and MAX. Updated values receive regenerated appearances

RemoveFormField deletes a loaded form field from the AcroForm field tree and removes the matching widget annotations from its pages. FlattenLoadedFormFields paints only the named fields into static content on their owning pages, removes their widget annotations, and preserves untouched fields and pages. An empty name array selects every field. The default permission gate refuses any structural change prohibited by DocMDP or FieldMDP signatures

FlattenFormFields retains the all-fields convenience contract and delegates loaded documents to the same signature-aware, page-local path. It returns the number of fields flattened, or zero when no matching form fields were present

Use SaveLoadedDocument to write a fully saved copy of the loaded object graph after direct field edits. For append-only workflows such as signed PDFs, load with BeginIncrementalUpdate, edit fields, and then call SaveIncrementalUpdate

Example

PDF.LoadFromFile('InputForm.pdf');
for I := 0 to PDF.GetFormFieldCount - 1 do
  Writeln(PDF.GetFormFieldName(I), ' = ', PDF.GetFormFieldValue(I));

for I := 0 to PDF.GetFormFieldOptionCount('Plan') - 1 do
  Writeln('Plan option ', I, ': ', PDF.GetFormFieldOptionValue('Plan', I));

Writeln('Customer description: ', PDF.GetFormFieldDescription('CustomerName'));
PDF.SetFormFieldValue('CustomerName', 'Bob');
PDF.SetFormFieldReadOnly('CustomerName', True);
PDF.RenameFormField('CustomerName', 'ClientName');
PDF.RemoveFormField('Approved');
PDF.RecalculateLoadedFormFields;
PDF.SaveLoadedDocument('UpdatedForm.pdf');

PDF.LoadFromFile('UpdatedForm.pdf');
if PDF.HasFormFields then
  Writeln('Plan exists: ', PDF.FormFieldExists('Plan'));
FlattenedCount := PDF.FlattenFormFields;
PDF.SaveLoadedDocument('FlattenedForm.pdf');

PDF.BeginIncrementalUpdate('SignedForm.pdf');
FlattenedCount := PDF.FlattenLoadedFormFields(['CalculatedTotal']);
PDF.SaveIncrementalUpdate('SignedForm-flattened.pdf');

See Also