You did not provide any parameters in the URL. We therefore
provide the default service, which is the automatic documentation of this tool (the Generic Query Tool). ';
// if the tool's URL is called without any parameters, we return the
// documentation in TAPIR XML format.
$output_string .= ' Generic Query Tool ';
$output_string .= ' 0.001 beta ';
$output_string .= ' bart.meganck@africamuseum.be ';
$output_string .= ' The Generic Query Tool allows you to contact most types of
data servers in TDWG/BioCASE context. You talk to this tool with HTTP GET statements,
and you get the answers back in a TAPIR response XML. The minimal information you need to provide
is the URL of the server you want to contact, in the "endpoint" variable. This will give you
the information about that server (protocol, data schema, ...). For more functionality, see
the parameter descriptions. ';
$output_string .= ' endpoint ';
$output_string .= ' op ';
$output_string .= ' timeout ';
$output_string .= ' start ';
$output_string .= ' limit ';
$output_string .= ' filter ';
$output_string .= ' count ';
$output_string .= ' responseschema ';
} else { //non-empty parameter string
// If parameters are passed, the endpoint parameter should be there
if ( !isset($_GET['endpoint']) || empty($_GET['endpoint']) ) {
$error_string .= ' "endpoint" parameter not specified, or empty. This parameter is required.
If you want a short manual for this tool, simply point your browser at
the base URL : '.$GQT_server_url.'';
} else { //ok : endpoint provided
$server_endpoint = urldecode($_GET['endpoint']);
// check endpoint syntax, add "http://" if necessary
if (substr($server_endpoint,0,7) != "http://") {
$error_string .= ' The URL you specified in the "endpoint" parameter did not begin
with "http://". We will add "http://" automatically, but if that does not
work you should check your URL again : "'.$server_endpoint.'" ';
$server_endpoint = "http://".$server_endpoint;
}
$req_destination = $server_endpoint;
// now check all other (optional) parameters
if (isset($_GET['op'])) {
$operation_name = urldecode($_GET['op']);
} else {
$error_string .= ' An "endpoint" parameter was given without an "op" (operation) parameter.
We therefore use the default operation "getEndpointInfo".
If you want a short overview of all parameters, simply point your browser at
the base URL of this tool : '.$GQT_server_url.'';
$operation_name = 'getEndpointInfo';
}
if (isset($_GET['timeout'])) {
$request_timeout = urldecode($_GET['timeout']);
}
ini_set('default_socket_timeout',$request_timeout);
if (isset($_GET['start'])) {
$req_start = urldecode($_GET['start']);
}
if (isset($_GET['limit'])) {
$req_limit = urldecode($_GET['limit']);
}
if (isset($_GET['filter'])) {
$req_filter = urldecode($_GET['filter']);
}
if (isset($_GET['count'])) {
$req_count = urldecode($_GET['count']);
}
if (isset($_GET['responseschema'])) {
$req_response_schema = urldecode($_GET['responseschema']);
}
// at this point we have a (hopefully valid) endpoint, so we send a request
// to get the endpoint's information. In case of the "getEndpointInfo"
// operation, that's all we need. For search operations, this will provide
// the basic information needed for constructing the query string.
// Build the HTTP POST datastring, with a single (and empty) parameter
$post_data = http_build_query(
array('request' => '')
);
$post_options = array('http' =>
array(
'method' => 'POST',
'header' => 'Content-type: application/x-www-form-urlencoded',
'content' => $post_data
)
);
// Build context and try server for response, catch any exceptions
$post_context = stream_context_create($post_options);
try {
$response = file_get_contents($server_endpoint, false, $post_context);
}
catch (Exception $error1) {
$error_string .= '';
}
// Try to put the response in an XML object, catch any errors
try {
$response_xml = new SimpleXMLElement($response);
} catch (Exception $error2) {
$error_string .= ' Server response could not be interpreted as XML. Usually, this
is due to a bad URL, or a server that is not (or too slowly) responding.
Try (1) checking the URL. (2) If the URL seems ok, try pointing at it
in another browser window : does the server respond ? how long does it take ?
(3) If the server does respond (only a bit slow), set the "timeout" parameter
a bit higher. If the server does NOT respond, well then this tool cannot do
its job properly, can it ? ';
}
// Get namespaces from XML response, determine server type from namespaces
if (isset ($response_xml)){
$communication_namespace = $response_xml->getDocNamespaces();
// TODO : response gives back xsi schemas as well : filter them out !
foreach ($communication_namespace as $ns_key => $ns_value){
if (strpos($ns_value,'digir') <> 0) {
$server_type = 'digir';
$server_namespace = $ns_value;
}
if (strpos($ns_value,'biocase') <> 0) {
$server_type = 'biocase';
$server_namespace = $ns_value;
}
if (strpos($ns_value,'tapir') <> 0) {
$server_type = 'tapir';
$server_namespace = $ns_value;
}
// TODO : change this to a switch, add default action
// ("namespace could not be found")
} // foreach
// See which operation is wanted, act accordingly
switch ($operation_name) {
case ('getEndpointInfo') :
// General info
$output_string .= ''.$server_type.'';
$output_string .= ''.$server_endpoint.'';
$output_string .= ''.$server_namespace.'';
// DiGIR-only info
if ($server_type=="digir") {
foreach($response_xml->content->metadata->provider->resource as $resource) {
$output_string .= ''.$resource->code.'';
}
$output_string .= ''
.$response_xml->content->metadata->provider->resource->conceptualSchema
.'';
} // digir server_type
if ($server_type=="biocase") {
// Get all possible error messages and warnings
foreach ($response_xml->diagnostics->diagnostic as $diagnostic) {
$output_string .= ''
.$diagnostic.'';
}
// Get all supported schemas
foreach ($response_xml->content->capabilities->SupportedSchemas as $supp_schema) {
foreach ($supp_schema->attributes() as $schema_key => $schema_value) {
if ($schema_key == "namespace") {
$output_string .= ''
.$schema_value.'';
} // if
} // foreach attribute
} // foreach supported schema
} // biocase server type
break; // case getEndpointInfo
case ('search') :
// Construction of search request
switch ($server_type) {
case ('biocase') :
$myBiocaseRequest = new Biocase_request();
$req_string = $myBiocaseRequest->generateBiocaseRequest($req_GQT_version,
$req_destination,
$req_start,
$req_limit,
$req_response_schema,
$req_filter,
$req_count);
break; // biocase
case ('digir'):
$request_catalogNumberTag = "CatalogNumber";
$myDigirRequest = new Digir_request();
echo("digir");
$req_string = $myDigirRequest->generateDigirRequest($req_resource,
$req_destination,
$req_filter,
$req_start,
$req_limit,
$req_catalogNumberTag);
break; //digir
case ('tapir'):
// TODO : implement TAPIR search query
break;
default :
// no default operation
break;
} // switch server_type
// Fill POST string for search request
$search_post_data = http_build_query(
array('request' => $req_string)
);
$search_post_options = array('http' =>
array(
'method' => 'POST',
'header' => 'Content-type: application/x-www-form-urlencoded',
'content' => $search_post_data
)
);
// Build context and try server for response, catch any exceptions
$search_post_context = stream_context_create($search_post_options);
try {
$search_response = file_get_contents($server_endpoint, false, $search_post_context);
} catch (Exception $error3) {
$error_string .= '';
}
// Build context and try server for response, catch any exceptions
try {
$search_response_xml = new SimpleXMLElement($search_response);
} catch (Exception $error4) {
$error_string .= ' Server response could not be interpreted as XML. Usually, this
is due to a bad URL, or a server that is not (or too slowly) responding.
Try (1) checking the URL. (2) If the URL seems ok, try pointing at it
in another browser window : does the server respond ? how long does it take ?
(3) If the server does respond (only a bit slow), set the "timeout" parameter
a bit higher. If the server does not respond at all, well then this tool
cannot help it, can it ? ';
}
// Extract response content from protocol, write to output
$output_string .= $search_response_xml->content->asXML();
$output_string .= $search_response_xml->content->count->asXML();
$diagnostic_string .= 'Got search response from the endpoint server.
The response content is available here under the "'.$operation_name.'" tag.';
break;
} // switch (operation)
} // if isset $response_xml
} //endpoint is provided
} // parameter string not empty
// Put the response and/or error messages into a TAPIR response XML
echo('');
echo('');
echo('');
echo('');
echo($GQT_server_url);
echo('');
echo('');
echo('');
echo('');
echo('<'.$operation_name.'>');
echo($output_string);
echo('');
echo(' ');
echo('');
echo($error_string);
echo('');
echo($diagnostic_string);
echo('');
echo('');
?>