Method: PDFium::Document#metadata

Defined in:
ext/pdfium_ext/document.cc

#metadata ⇒ Hash

Retrieves and optionally sets the metadata on a document. Returns a hash with the following keys:

:title, :author :subject, :keywords, :creator, :producer, :creation_date, :mod_date

An empty Hash will be returned if the metadata cannot be read

All values in the hash are encoded as UTF-16LE strings.

If caled with a block, the values will be passed to it and updates written back to the Document

Example

pdf = PDFium::Document.new( "test.pdf" )
pdf.metadata do | md |
    md[:title]  = "My Awesome PDF"
    md[:author] = "Nathan Stitt"
end
pdf.metadata[:author] # => "Nathan Stitt"

Returns:

  • (Hash) 


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# File 'ext/pdfium_ext/document.cc', line 205

VALUE
document_metadata(int argc, VALUE *argv, VALUE self)
{
    auto doc = RB2DOC(self);
    VALUE metadata = rb_hash_new();
    CPDF_Dictionary* info = doc->GetInfo();
    if (!info)
        return metadata;

    VALUE block;
    rb_scan_args(argc, argv, "0&", &block);

    std::map<std::string, std::string> keys = {
        { "Title",        "title"  },
        { "Author",       "author" },
        { "Subject",      "subject" },
        { "Keywords",     "keywords"},
        { "Creator",      "creator" },
        { "Producer",     "producer"},
        { "CreationDate", "creation_date" },
        { "ModDate",      "mod_date" }
    };

    for (auto& kv : keys) {
        rb_hash_aset(metadata,
                     ID2SYM( rb_intern( kv.second.c_str() ) ),
                     RB::to_string( info->GetUnicodeText( kv.first.c_str() ) )
                     );
    }

    if (RTEST(block)){
        rb_yield( metadata );
        for (auto& kv : keys) {
            VALUE value = RB::get_option(metadata, kv.second);
            auto bs = CFX_ByteString( RSTRING_PTR(value), RSTRING_LEN(value) );
            info->SetAtString(kv.first.c_str(), bs);
        }
    }

    return metadata;
}