Using metadata and files¶

Grabbing a single object¶

In many cases it will makes sense to only request a single known object. Objects are identified by their GUID. We can grab a single object by its GUID with PortalClient::Object()::GetByObjectGUID():

<?php
$serviceResult = $client->Object()->GetByObjectGUID(
  "00000000-0000-0000-0000-00004e040016" // objectGUID
  , $accessPointGUID // accessPointGuid
  , true                          // includeMetadata
  , true                          // includeFiles
  , true                          // includeObjectRelations
  , false                         // includeAccessPoints
);
$object = $serviceResult->MCM()->Results()[0];
echo "Grabbed object (GUID): " . $object->GUID;
?>

Files¶

Files belonging to an object can be of different types – video, audio, images and basically any other kind of file. The files can be found in the Files attribute of the objects in serviceResult->MCM()->Results():

<table id="file-table">
  <thead>
    <tr>
      <th>FormatType</th>
      <th>Filename</th>
      <th>URL</th>
      <th>Representation</th>
    </tr>
  </thead>
  <tbody>
<?php
$serviceResult = $client->Object()->GetByObjectGUID(
  "00000000-0000-0000-0000-00004e040016" // objectGUID
  , $accessPointGUID // accessPointGuid
  , true                          // includeMetadata
  , true                          // includeFiles
  , true                          // includeObjectRelations
  , false                         // includeAccessPoints
);
$object = $serviceResult->MCM()->Results()[0];

for ($i = 0; $i < count($object->Files); $i++) {
  $tr = "";
  $tr .= "<tr>";
  $tr .= "<td>" . $object->Files[$i]->FormatType . "</td>";
  $tr .= "<td>" . $object->Files[$i]->Filename . "</td>";
  $tr .= "<td>" . $object->Files[$i]->URL . "</td>";
  if ($object->Files[$i]->FormatType == "Image") {
    $tr .= "<td><img src=\"" . $object->Files[$i]->URL . "\"></td>";
  } else {
    $tr .= "<td>No representation</td>";
  }
  $tr .= "</tr>";
  echo $tr;
}
?>
  </tbody>
</table>

Running the code you should get the output:

FormatType	Filename	URL	Representation
Image	db_fo_sa_00564.jpg	http://www.kb.dk/imageService//online_master_arkiv_9/non-archival/Images/BLADTE_VANDMAERKER//db_fo_sa_00564.jpg
Image	db_fo_sa_00564.jpg	http://www.kb.dk/imageService/w150/online_master_arkiv_9/non-archival/Images/BLADTE_VANDMAERKER/db_fo_sa_00564.jpg

Metadata¶

Now, we have an object and possibly some files related to it. But we might still have some questions: What’s the name of the object? What color does it have? What length? Texture? Taste?
– and what noise does it make when it’s out of paper?
These are questions for the metadata.

The CHAOS database can be filled with all kinds of objects. What kind of objects you can expect to get from your specific database should be known to you already. Or at the latest when you start working with your CHAOS database.

The metadata of an object is a list of XML documents with related XML schemas. Again, the structure of these XML document is specific to your database, and I recommend that you familiarize yourself the structure of these documents before you begin doing serious work with CHAOS. In this case we’re just experimenting and getting to know the interface - so let’s have a look. The metadata can be found in the Metadatas attribute of the objects in serviceResult->MCM()->Results():

Metadatas is an array of strings containing XML documents. Let’s have a look:

<?php
$serviceResult = $client->Object()->GetByObjectGUID(
  "00000000-0000-0000-0000-00004e040016" // objectGUID
  , $accessPointGUID // accessPointGuid
  , true                          // includeMetadata
  , true                          // includeFiles
  , true                          // includeObjectRelations
  , false                         // includeAccessPoints
);
$object = $serviceResult->MCM()->Results()[0];

echo "<pre>" . $object->Metadatas[1]->MetadataXML . "</pre>";
?>

Our object’s metadata:

<DKA>
  <Title>Uden titel</Title>
  <Abstract>En mand i profil med sideskilning og et mut ansigtsudtryk</Abstract>
  <Description />
  <Organization>Det Kongelige Bibliotek</Organization>
  <Type />
  <CreatedDate>2010-10-06T00:00:00</CreatedDate>
  <FirstPublishedDate>2010-10-06T00:00:00</FirstPublishedDate>
  <Identifier>108593</Identifier>
  <Contributor />
  <Creator>
    <Person Name="ukendt" Role="Creator" />
  </Creator>
  <TechnicalComment />
  <Location />
  <RightsDescription>Billedet er beskyttet af loven om ophavsret</RightsDescription>
  <Categories />
</DKA>

Parsing XML with PHP can be done in a number of ways. In the following example I will use SimpleXML to parse and access the XML.

<?php
$serviceResult = $client->Object()->GetByObjectGUID(
  "00000000-0000-0000-0000-00004e040016" // objectGUID
  , $accessPointGUID // accessPointGuid
  , true                          // includeMetadata
  , true                          // includeFiles
  , true                          // includeObjectRelations
  , false                         // includeAccessPoints
);
$object = $serviceResult->MCM()->Results()[0];

$xmlstr = $object->Metadatas[1]->MetadataXML;

$xmlDoc = new SimpleXMLElement($xmlstr);

$obj_title = $xmlDoc->Title;
$obj_desc = $xmlDoc->Abstract;

echo "Title: " . $obj_title . "<br>";
echo "Abstract: " . $obj_desc;
?>

The result should be:

Title: Uden titel
Abstract: En mand i profil med sideskilning og et mut ansigtsudtryk

The next section will teach you about handling errors when dealing with CHAOS.Portal.