John Davidson

Message:

Good day everyone!

I have an RDF file something like:

<?xml version="1.0" encoding="UTF-8"?>

<rdf:RDF xml:lang="en"

  xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#"

  xmlns:rdfs="http://www.w3.org/2000/01/rdf-schema#"

  xmlns:tool="https://www.toptools4learning.com/">

  <rdf:Description rdf:about="YouTube">

    <tool:rank>1</tool:rank>

    <tool:reference rdf:resource="https://www.toptools4learning.com/"/>

    <tool:type>learning</tool:type>

    <tool:category>web-based</tool:category>

    <tool:domain>any</tool:domain>

  </rdf:Description>

  <rdf:Description rdf:about="Wikipedia">

    <tool:rank>11</tool:rank>

    <tool:reference rdf:resource="https://www.toptools4learning.com/"/>

    <tool:type>learning</tool:type>

    <tool:category>web-based</tool:category>

    <tool:domain>any</tool:domain>

  </rdf:Description>

</rdf:RDF>

What I would like to do is I would like to implement a feature for my web application in PHP that would allow the user to upload an RDF File, and after clicking the submit button, it will generate the RDF graph of the uploaded file.

I was taking a look at EasyRDF tutorials, and in one of the tutorials it showed how to visualize an RDF graph by providing a valid URI:

<?php

   require_once __dir__."/autoload.php";

   require_once __DIR__."/html_tag_helper.php";

?>



<div style="margin: 10px">

   <?= form_tag() ?>

     URI: <?= text_field_tag('uri', ' ', array('size'=>80)) ?><br />

     Format: <?= label_tag('format_html', 'HTML').' '.radio_button_tag('format', 'html', true) ?>

             <?= label_tag('format_text', 'Text').' '.radio_button_tag('format', 'text') ?><br />

   <?= submit_tag() ?>

   <?= form_end_tag() ?>

</div>



<?php

   if (isset($_REQUEST['uri'])) {

       $graph = \EasyRdf\Graph::newAndLoad($_REQUEST['uri']);

       if ($graph) {

           if (isset($_REQUEST['format']) && $_REQUEST['format'] == 'text') {

               print "<pre>".$graph->dump('text')."</pre>";

           } else {

               $dump = $graph->dump('html');

               print preg_replace_callback("/ href='([^#][^']*)'/", 'makeLinkLocal', $dump);

           }

       } else {

           print "<p>Failed to create graph.</p>";

       }

   }



   # Callback function to re-write links in the dump to point back to this script

   function makeLinkLocal($matches)

   {

       $href = $matches[1];

       return " href='?uri=".urlencode($href)."#$href'";

   }

?>

My idea is the same but instead of URIs, I'd like to do this by uploading an RDF file. I saw a form tag helper from the Rails API called file_upload_tag(), however I'm not quite sure how to work with it.

Any suggestions would be greatly appreciated!

---

My Answer:


Resource 1
John Doe


Resource 2
Jane Smith



To visualize this RDF graph in PHP, you can use a library like EasyRdf. Here's an example code snippet to load and visualize the RDF graph from the uploaded RDF file:
php
parseFile('path/to/uploaded.rdf');
// Iterate over each triple in the graph and print it
foreach ($graph->toRdfPhp() as $subject => $properties) {
echo "Subject: $subject\n";
foreach ($properties as $predicate => $objects) {
echo " Predicate: $predicate\n";
foreach ($objects as $object) {
echo " Object: $object['value']\n";
}
}
}
?>

This code snippet will load the uploaded RDF file using EasyRdf, iterate over each triple in the graph, and print out the subject, predicate, and object of each triple. You can further customize this code to visualize the RDF graph in a more user-friendly format, such as a graph visualization or a table.