fdf_get_value

(PHP 4, PHP 5, PHP 7)

fdf_get_valueGet the value of a field

说明

mixed fdf_get_value ( resource $fdf_document , string $fieldname [, int $which = -1 ] )

Gets the value for the requested field.

参数

fdf_document

The FDF document handle, returned by fdf_create(), fdf_open() or fdf_open_string().

fieldname

Name of the FDF field, as a string.

which

Elements of an array field can be retrieved by passing this optional parameter, starting at zero. For non-array fields, this parameter will be ignored.

返回值

Returns the field value.

更新日志

版本 说明
4.3.0 Support for arrays and the which parameter were added.

参见

User Contributed Notes

mclinden at informed dot net 17-Sep-2002 11:35
(i filed a bug report/feature request for this on bugs.php.net and assigned it to myself hartmut@php.net)

The default behavior for the FDF Toolkit is to return an FDFErcNoValue for the FDFGetValue when the field exists but has no value.

Whether or not this is truly an error is debateable. It seems to become an issue in documents created by Acrobat 5 when optional fields are included in a form with required fields since the default behavior seems to be to populate the HTTP_FDF_DATA with the results of the FDFNextFieldName enumerator, which would include the fields which have no value.

This would not be a problem except that the PHP function fdf_get_value() does not specifically test for the FDFErcNoValue condition but, instead, tests for the more general FDFErcOK. If this value is not the result of the error code, the system issues warnings (the display of which could be turned off), but the broader question is, should this be a warning condition at all?

Put another way, should a return of FDFErcNoValue for FDFGetValue be considered an event worth generating a warning?