在PHP中通过Pdftk使用FDF填充FieldType:Choice字段和多个选项

我在用 Pdftk pdftk-php (基于forge-fdf)。我想生成一个可以与PDF合并的FDF来填写一个带有多个选项的下拉文本框。默认情况下,pdftk php的工作方式是只使用一个值填充下拉列表;向它传递数组不起作用。

以下是pdftk filename dump_data_字段的相关输出。

FieldType: Choice
FieldName: VehicleIDData1
FieldFlags: 4587520
FieldJustification: Left

根据PDF 1.2规范中的这个示例,下拉菜单似乎需要FDF中的/Opt选项。

%FDF-1.2
1 0 obj <<
/FDF <<
/Fields
[
<<
/T (My Children)
/V (Tali)
/Opt [(Maya) (Adam) (Tali)]
November 12, 1996
: 379
>>
]
/F (Dependents.pdf)
>>
>>
endobj
trailer
<</Root 1 0 R>>
%%EOF

specification

Opt
array
(Required; choice fields only) An array of options to be presented to the user. Each element of the array can take either of two forms:
•A text string representing one of the available options
•A two-element array consisting of a text string representing one of the available options and a default appearance string for constructing the item’s appearance dynamically at viewing time (see “Variable Text” on page 677)

pdftk php不使用/Opt;如果向它传递字段的值数组,它将使用/Kids,这不会填充其他下拉项。我试图修改程序以使用/Opt代替,但是得到的pdf没有区别。我做错什么了?

protected function forge_fdf_fields( &$fdf,
          &$fdf_data,
          &$fields_hidden,
          &$fields_readonly,
          $accumulated_name,
          $strings_b ) // true <==> $fdf_data contains string data
    //
    // string data is used for text fields, combo boxes and list boxes;
    // name data is used for checkboxes and radio buttons, and
    // /Yes and /Off are commonly used for true and false
{
    if( 0< strlen( $accumulated_name ) ) {
        $accumulated_name.= '.'; // append period seperator
    }

    foreach( $fdf_data as $key => $value ) {
    // we use string casts to prevent numeric strings from being silently converted to numbers
        $fdf.= "<< "; // open dictionary

        if( gettype($value)== 'array' ) { // parent; recurse
            $fdf.= "/T (".$this->escape_pdf_string( (string)$key ).") "; // partial field name
            $fdf .= "/V (" . $this->escape_pdf_string((string)$value[0]) . ") ";

            $fdf .= "/Opt [";
            foreach ($value as $option) {
                $fdf .= "(" . $this->escape_pdf_string((string)$option) . ") ";
            }

            /* This is the older code I'm replacing.
            $fdf.= "/Kids [ ";                                    // open Kids array

            // recurse
            $this->forge_fdf_fields( $fdf,
                $value,
                $fields_hidden,
                $fields_readonly,
                $accumulated_name. (string)$key,
                $strings_b );
            */

            $fdf.= "] "; // close Kids array
        } else {

            // field name
            $fdf.= "/T (".$this->escape_pdf_string( (string)$key ).") ";

            // field value
            if( $strings_b ) { // string
                $fdf.= "/V (".$this->escape_pdf_string( (string)$value ).") ";
            }
            else { // name
                $fdf.= "/V /".$this->escape_pdf_name( (string)$value ). " ";
            }

            // field flags
            $this->forge_fdf_fields_flags( $fdf,
                        $accumulated_name. (string)$key,
                        $fields_hidden,
                        $fields_readonly );
        }
        $fdf.= ">> \x0d"; // close dictionary
    }
}