Added resolve method for @context URLs.

This commit is contained in:
Dave Longley 2011-10-27 19:00:01 -04:00
parent 093e3277d8
commit a7206c8331

View file

@ -70,6 +70,12 @@ function jsonld_compact($ctx, $input)
$tmp = array($input);
}
// merge context if it is an array
if(is_array($ctx))
{
$ctx = jsonld_merge_contexts(new stdClass, $ctx);
}
foreach($tmp as $value)
{
// setup output context
@ -109,9 +115,25 @@ function jsonld_compact($ctx, $input)
*/
function jsonld_merge_contexts($ctx1, $ctx2)
{
// merge first context if it is an array
if(is_array($ctx1))
{
$ctx1 = jsonld_merge_contexts($ctx1, $ctx2);
}
// copy context to merged output
$merged = _clone($ctx1);
if(is_array($ctx2))
{
// merge array of contexts in order
foreach($ctx2 as $ctx)
{
$merged = jsonld_merge_contexts($merged, $ctx);
}
}
else
{
// if the new context contains any IRIs that are in the merged context,
// remove them from the merged context, they will be overwritten
foreach($ctx2 as $key => $value)
@ -156,6 +178,7 @@ function jsonld_merge_contexts($ctx1, $ctx2)
}
}
}
}
return $merged;
}
@ -244,6 +267,114 @@ function jsonld_frame($input, $frame, $options=null)
return $rval;
}
/**
* Resolves external @context URLs. Every @context URL in the given JSON-LD
* object is resolved using the given URL-resolver function. Once all of
* the @contexts have been resolved, the method will return. If an error
* is encountered, an exception will be thrown.
*
* @param input the JSON-LD input object (or array).
* @param resolver the resolver method that takes a URL and returns a JSON-LD
* serialized @context or throws an exception.
*
* @return the fully-resolved JSON-LD output (object or array).
*/
function jsonld_resolve($input, $resolver)
{
// find all @context URLs
$urls = new ArrayObject();
_findUrls($input, $urls, false);
// resolve all URLs
foreach($urls as $url => $value)
{
$result = call_user_func($resolver, $url);
if(!is_string($result))
{
// already deserialized
$urls[$url] = $result;
}
else
{
// deserialize JSON
$tmp = json_decode($result);
if($tmp === null)
{
throw new Exception(
'Could not resolve @context URL ("$url"), ' .
'malformed JSON detected.');
}
$urls[$url] = $tmp;
}
}
// replace @context URLs in input
_findUrls($input, $urls, true);
return $input;
}
/**
* Finds all of the @context URLs in the given input and replaces them
* if requested by their associated values in the given URL map.
*
* @param input the JSON-LD input object.
* @param urls the URLs ArrayObject.
* @param replace true to replace, false not to.
*/
function _findUrls($input, $urls, $replace)
{
if(is_array($input))
{
foreach($input as $v)
{
_findUrls($v);
}
}
else if(is_object($input))
{
foreach($input as $key => $value)
{
if($key === '@context')
{
// @context is an array that might contain URLs
if(is_array($value))
{
foreach($value as $idx => $v)
{
if(is_string($v))
{
// replace w/resolved @context if appropriate
if($replace)
{
$input->{$key}[$idx] = $urls[$v];
}
// unresolved @context found
else
{
$urls[$v] = new stdClass();
}
}
}
}
else if(is_string($value))
{
// replace w/resolved @context if appropriate
if($replace)
{
$input->$key = $urls[$value];
}
// unresolved @context found
else
{
$urls[$value] = new stdClass();
}
}
}
}
}
}
/**
* Gets the keywords from a context.
*