Task 825: .X3D File Format
Task 825: .X3D File Format
1. List of all the properties of this file format intrinsic to its file system
Based on the official X3D specifications for the XML encoding (which is the primary format for .x3d files), the intrinsic properties include the XML declaration details, DOCTYPE identifiers, root element attributes, and standardized metadata fields from the optional <head> section. These are structural elements inherent to the file format's definition and validation schema.
- XML Version (e.g., "1.0")
- Encoding (e.g., "UTF-8")
- DOCTYPE Public Identifier (e.g., "ISO//Web3D//DTD X3D 4.0//EN")
- DOCTYPE System Identifier (e.g., "https://www.web3d.org/specifications/x3d-4.0.dtd")
- X3D Profile (e.g., "Full", "Immersive")
- X3D Version (e.g., "4.0", "3.3")
- xmlns:xsd (XML namespace for schema instance, e.g., "http://www.w3.org/2001/XMLSchema-instance")
- xsd:noNamespaceSchemaLocation (Schema URL, e.g., "https://www.web3d.org/specifications/x3d-4.0.xsd")
- Metadata Title (from )
- Metadata Description (from )
- Metadata Created (from )
- Metadata Modified (from )
- Metadata Creator (from )
- Metadata Image (from )
- Metadata Reference (from ; may have multiple)
- Metadata Identifier (from )
- Metadata License (from )
- Metadata Generator (from )
Note: Metadata fields are optional and based on recommended names in the specification. Not all files will have all fields, and some (like "reference") can appear multiple times. The file extension is .x3d, and the MIME type is model/x3d+xml, but these are not extracted from the file contents themselves.
2. Two direct download links for files of format .X3D
- https://people.math.sc.edu/Burkardt/data/x3d/hello_world.x3d
- https://people.math.sc.edu/Burkardt/data/x3d/triangle.x3d
(These are simple sample .x3d files hosted publicly for data format examples.)
3. Ghost blog embedded html javascript that allows a user to drag n drop a file of format .X3D and it will dump to screen all these properties
Assuming "ghost blog embedded" means embeddable HTML/JS code (e.g., for a Ghost blog post), here's a self-contained HTML snippet with JavaScript for drag-and-drop functionality. It reads the file, parses it, extracts the properties listed in #1, and displays them on screen. It handles multiple metadata values where applicable.
Drag and drop .x3d file here
4. Python class that can open any file of format .X3D and decode read and write and print to console all the properties from the above list
Here's a Python class using xml.etree.ElementTree for parsing and re for header extraction. It loads the file, extracts/prints properties, and can write a modified version (e.g., with the same properties but an empty scene for simplicity).
import xml.etree.ElementTree as ET
import re
class X3DParser:
def __init__(self):
self.xml_ver = None
self.encoding = None
self.pub_id = None
self.sys_id = None
self.profile = None
self.x3d_ver = None
self.xmlns_xsd = None
self.schema_loc = None
self.metadata = {}
self.tree = None
self.root = None
def load(self, filename):
with open(filename, 'r', encoding='utf-8') as f:
text = f.read()
xml_match = re.search(r'<\?xml version="([^"]+)" encoding="([^"]+)"\?>', text)
if xml_match:
self.xml_ver = xml_match.group(1)
self.encoding = xml_match.group(2)
doc_match = re.search(r'<!DOCTYPE X3D PUBLIC "([^"]+)" "([^"]+)"\>', text)
if doc_match:
self.pub_id = doc_match.group(1)
self.sys_id = doc_match.group(2)
self.tree = ET.parse(filename)
self.root = self.tree.getroot()
self.profile = self.root.attrib.get('profile', 'N/A')
self.x3d_ver = self.root.attrib.get('version', 'N/A')
self.xmlns_xsd = self.root.attrib.get('xmlns:xsd', 'N/A')
self.schema_loc = self.root.attrib.get('xsd:noNamespaceSchemaLocation', 'N/A')
head = self.root.find('head')
if head:
for meta in head.findall('meta'):
name = meta.attrib.get('name')
content = meta.attrib.get('content')
if name and content:
if name in self.metadata:
if not isinstance(self.metadata[name], list):
self.metadata[name] = [self.metadata[name]]
self.metadata[name].append(content)
else:
self.metadata[name] = content
def print_properties(self):
print(f"XML Version: {self.xml_ver or 'N/A'}")
print(f"Encoding: {self.encoding or 'N/A'}")
print(f"DOCTYPE Public Identifier: {self.pub_id or 'N/A'}")
print(f"DOCTYPE System Identifier: {self.sys_id or 'N/A'}")
print(f"X3D Profile: {self.profile}")
print(f"X3D Version: {self.x3d_ver}")
print(f"xmlns:xsd: {self.xmlns_xsd}")
print(f"xsd:noNamespaceSchemaLocation: {self.schema_loc}")
for key, val in self.metadata.items():
if isinstance(val, list):
print(f"{key}: {', '.join(val)}")
else:
print(f"{key}: {val}")
def write(self, filename):
if not self.root:
raise ValueError("No data loaded to write.")
header = f'<?xml version="{self.xml_ver or "1.0"}" encoding="{self.encoding or "UTF-8"}"?>\n'
header += f'<!DOCTYPE X3D PUBLIC "{self.pub_id or ""}" "{self.sys_id or ""}">\n'
# Rebuild head if metadata changed
head = self.root.find('head')
if head is None:
head = ET.SubElement(self.root, 'head')
else:
for child in list(head):
head.remove(child)
for key, val in self.metadata.items():
vals = val if isinstance(val, list) else [val]
for v in vals:
meta = ET.SubElement(head, 'meta')
meta.attrib['name'] = key
meta.attrib['content'] = v
# Ensure Scene exists
if self.root.find('Scene') is None:
ET.SubElement(self.root, 'Scene')
xml_str = ET.tostring(self.root, encoding='unicode', method='xml')
with open(filename, 'w', encoding='utf-8') as f:
f.write(header + xml_str)
# Example usage:
# parser = X3DParser()
# parser.load('example.x3d')
# parser.print_properties()
# parser.write('output.x3d')
5. Java class that can open any file of format .X3D and decode read and write and print to console all the properties from the above list
Here's a Java class using javax.xml.parsers for parsing and regex for header extraction. It loads, extracts/prints, and writes (with Transformer for output).
import java.io.*;
import java.util.*;
import java.util.regex.*;
import javax.xml.parsers.*;
import javax.xml.transform.*;
import javax.xml.transform.dom.*;
import javax.xml.transform.stream.*;
import org.w3c.dom.*;
public class X3DParser {
private String xmlVer;
private String encoding;
private String pubId;
private String sysId;
private String profile;
private String x3dVer;
private String xmlnsXsd;
private String schemaLoc;
private Map<String, List<String>> metadata = new HashMap<>();
private Document doc;
public void load(String filename) throws Exception {
BufferedReader br = new BufferedReader(new FileReader(filename));
String line;
StringBuilder sb = new StringBuilder();
while ((line = br.readLine()) != null) {
sb.append(line).append("\n");
}
br.close();
String text = sb.toString();
Pattern xmlPat = Pattern.compile("<\\?xml version=\"([^\"]+)\" encoding=\"([^\"]+)\"\\?>");
Matcher xmlMat = xmlPat.matcher(text);
if (xmlMat.find()) {
xmlVer = xmlMat.group(1);
encoding = xmlMat.group(2);
}
Pattern docPat = Pattern.compile("<!DOCTYPE X3D PUBLIC \"([^\"]+)\" \"([^\"]+)\"\\>");
Matcher docMat = docPat.matcher(text);
if (docMat.find()) {
pubId = docMat.group(1);
sysId = docMat.group(2);
}
DocumentBuilderFactory dbf = DocumentBuilderFactory.newInstance();
DocumentBuilder db = dbf.newDocumentBuilder();
doc = db.parse(new File(filename));
Element root = doc.getDocumentElement();
profile = root.getAttribute("profile");
x3dVer = root.getAttribute("version");
xmlnsXsd = root.getAttribute("xmlns:xsd");
schemaLoc = root.getAttribute("xsd:noNamespaceSchemaLocation");
NodeList heads = root.getElementsByTagName("head");
if (heads.getLength() > 0) {
Node head = heads.item(0);
NodeList metas = ((Element) head).getElementsByTagName("meta");
for (int i = 0; i < metas.getLength(); i++) {
Element meta = (Element) metas.item(i);
String name = meta.getAttribute("name");
String content = meta.getAttribute("content");
metadata.computeIfAbsent(name, k -> new ArrayList<>()).add(content);
}
}
}
public void printProperties() {
System.out.println("XML Version: " + (xmlVer != null ? xmlVer : "N/A"));
System.out.println("Encoding: " + (encoding != null ? encoding : "N/A"));
System.out.println("DOCTYPE Public Identifier: " + (pubId != null ? pubId : "N/A"));
System.out.println("DOCTYPE System Identifier: " + (sysId != null ? sysId : "N/A"));
System.out.println("X3D Profile: " + (profile != null ? profile : "N/A"));
System.out.println("X3D Version: " + (x3dVer != null ? x3dVer : "N/A"));
System.out.println("xmlns:xsd: " + (xmlnsXsd != null ? xmlnsXsd : "N/A"));
System.out.println("xsd:noNamespaceSchemaLocation: " + (schemaLoc != null ? schemaLoc : "N/A"));
for (Map.Entry<String, List<String>> entry : metadata.entrySet()) {
System.out.println(entry.getKey() + ": " + String.join(", ", entry.getValue()));
}
}
public void write(String filename) throws Exception {
if (doc == null) {
throw new IllegalStateException("No data loaded to write.");
}
// Rebuild metadata in head
NodeList heads = doc.getElementsByTagName("head");
Element head;
if (heads.getLength() == 0) {
head = doc.createElement("head");
doc.getDocumentElement().appendChild(head);
} else {
head = (Element) heads.item(0);
while (head.hasChildNodes()) {
head.removeChild(head.getFirstChild());
}
}
for (Map.Entry<String, List<String>> entry : metadata.entrySet()) {
for (String val : entry.getValue()) {
Element meta = doc.createElement("meta");
meta.setAttribute("name", entry.getKey());
meta.setAttribute("content", val);
head.appendChild(meta);
}
}
// Ensure Scene
if (doc.getElementsByTagName("Scene").getLength() == 0) {
Element scene = doc.createElement("Scene");
doc.getDocumentElement().appendChild(scene);
}
TransformerFactory tf = TransformerFactory.newInstance();
Transformer transformer = tf.newTransformer();
transformer.setOutputProperty(OutputKeys.INDENT, "yes");
if (pubId != null) transformer.setOutputProperty(OutputKeys.DOCTYPE_PUBLIC, pubId);
if (sysId != null) transformer.setOutputProperty(OutputKeys.DOCTYPE_SYSTEM, sysId);
DOMSource source = new DOMSource(doc);
StreamResult result = new StreamResult(new File(filename));
transformer.transform(source, result);
}
// Example usage:
// public static void main(String[] args) throws Exception {
// X3DParser parser = new X3DParser();
// parser.load("example.x3d");
// parser.printProperties();
// parser.write("output.x3d");
// }
}
6. Javascript class that can open any file of format .X3D and decode read and write and print to console all the properties from the above list
Here's a JavaScript class (for Node.js or browser; assumes FileReader or fs for reading). It parses with DOMParser, extracts/prints to console, and has a toString method for writing output.
class X3DParser {
constructor() {
this.xmlVer = null;
this.encoding = null;
this.pubId = null;
this.sysId = null;
this.profile = null;
this.x3dVer = null;
this.xmlnsXsd = null;
this.schemaLoc = null;
this.metadata = {};
this.originalText = null; // For full write, but simplified
}
// Load from text (e.g., from FileReader.result or fs.readFileSync)
load(text) {
this.originalText = text;
const xmlMatch = text.match(/<\?xml version="([^"]+)" encoding="([^"]+)"\?>/);
this.xmlVer = xmlMatch ? xmlMatch[1] : 'N/A';
this.encoding = xmlMatch ? xmlMatch[2] : 'N/A';
const docMatch = text.match(/<!DOCTYPE X3D PUBLIC "([^"]+)" "([^"]+)"\>/);
this.pubId = docMatch ? docMatch[1] : 'N/A';
this.sysId = docMatch ? docMatch[2] : 'N/A';
const parser = new DOMParser();
const xml = parser.parseFromString(text, "text/xml");
const root = xml.getElementsByTagName('X3D')[0];
if (root) {
this.profile = root.getAttribute('profile') || 'N/A';
this.x3dVer = root.getAttribute('version') || 'N/A';
this.xmlnsXsd = root.getAttribute('xmlns:xsd') || 'N/A';
this.schemaLoc = root.getAttribute('xsd:noNamespaceSchemaLocation') || 'N/A';
const metas = xml.getElementsByTagName('meta');
for (let m of metas) {
const name = m.getAttribute('name');
const content = m.getAttribute('content');
if (name && content) {
if (this.metadata[name]) {
if (!Array.isArray(this.metadata[name])) this.metadata[name] = [this.metadata[name]];
this.metadata[name].push(content);
} else {
this.metadata[name] = content;
}
}
}
}
}
printProperties() {
console.log(`XML Version: ${this.xmlVer}`);
console.log(`Encoding: ${this.encoding}`);
console.log(`DOCTYPE Public Identifier: ${this.pubId}`);
console.log(`DOCTYPE System Identifier: ${this.sysId}`);
console.log(`X3D Profile: ${this.profile}`);
console.log(`X3D Version: ${this.x3dVer}`);
console.log(`xmlns:xsd: ${this.xmlnsXsd}`);
console.log(`xsd:noNamespaceSchemaLocation: ${this.schemaLoc}`);
for (let key in this.metadata) {
const val = Array.isArray(this.metadata[key]) ? this.metadata[key].join(', ') : this.metadata[key];
console.log(`${key}: ${val}`);
}
}
// Write: Generates a basic file string with properties (empty scene; for full, use a library)
toString() {
let header = `<?xml version="${this.xmlVer || '1.0'}" encoding="${this.encoding || 'UTF-8'}"?>\n`;
header += `<!DOCTYPE X3D PUBLIC "${this.pubId || ''}" "${this.sysId || ''}">\n`;
let x3d = `<X3D profile="${this.profile || ''}" version="${this.x3dVer || ''}" xmlns:xsd="${this.xmlnsXsd || ''}" xsd:noNamespaceSchemaLocation="${this.schemaLoc || ''}">\n`;
x3d += `<head>\n`;
for (let key in this.metadata) {
const vals = Array.isArray(this.metadata[key]) ? this.metadata[key] : [this.metadata[key]];
for (let val of vals) {
x3d += `<meta name="${key}" content="${val}"/>\n`;
}
}
x3d += `</head>\n<Scene></Scene>\n</X3D>`;
return header + x3d;
}
}
// Example usage (browser with FileReader or Node with fs):
// const parser = new X3DParser();
// parser.load(fileText);
// parser.printProperties();
// console.log(parser.toString()); // Or fs.writeFileSync('output.x3d', parser.toString());
7. Write a c class that can open any file of format .X3D and decode read and write and print to console all the properties from the above list
Since standard C lacks classes and built-in XML parsing, this is implemented as a C++ class (common for "c class" in such contexts) using <regex> and string operations for simple parsing (no external libs). It loads, extracts/prints, and writes a basic file.
#include <iostream>
#include <fstream>
#include <string>
#include <regex>
#include <map>
#include <vector>
#include <sstream>
class X3DParser {
public:
std::string xmlVer;
std::string encoding;
std::string pubId;
std::string sysId;
std::string profile;
std::string x3dVer;
std::string xmlnsXsd;
std::string schemaLoc;
std::map<std::string, std::vector<std::string>> metadata;
void load(const std::string& filename) {
std::ifstream file(filename);
std::stringstream buffer;
buffer << file.rdbuf();
std::string text = buffer.str();
std::regex xmlRegex(R"(<\?xml version="([^"]+)" encoding="([^"]+)"\?>)");
std::smatch match;
if (std::regex_search(text, match, xmlRegex)) {
xmlVer = match[1];
encoding = match[2];
}
std::regex docRegex(R"(<!DOCTYPE X3D PUBLIC "([^"]+)" "([^"]+)"\>)");
if (std::regex_search(text, match, docRegex)) {
pubId = match[1];
sysId = match[2];
}
// Extract root attributes
size_t x3dPos = text.find("<X3D");
if (x3dPos != std::string::npos) {
size_t endPos = text.find(">", x3dPos);
std::string rootStr = text.substr(x3dPos, endPos - x3dPos + 1);
std::regex attrRegex(R"(\s(profile|version|xmlns:xsd|xsd:noNamespaceSchemaLocation)="([^"]*)")");
auto iter = std::sregex_iterator(rootStr.begin(), rootStr.end(), attrRegex);
for (std::sregex_iterator i = iter; i != std::sregex_iterator(); ++i) {
std::smatch m = *i;
std::string attr = m[1];
std::string val = m[2];
if (attr == "profile") profile = val;
else if (attr == "version") x3dVer = val;
else if (attr == "xmlns:xsd") xmlnsXsd = val;
else if (attr == "xsd:noNamespaceSchemaLocation") schemaLoc = val;
}
}
// Extract metadata
size_t headPos = text.find("<head>");
if (headPos != std::string::npos) {
size_t endHead = text.find("</head>", headPos);
std::string headStr = text.substr(headPos, endHead - headPos + 7);
std::regex metaRegex(R"(<meta name="([^"]+)" content="([^"]+)"\s*/?>)");
auto metaIter = std::sregex_iterator(headStr.begin(), headStr.end(), metaRegex);
for (std::sregex_iterator i = metaIter; i != std::sregex_iterator(); ++i) {
std::smatch m = *i;
std::string name = m[1];
std::string content = m[2];
metadata[name].push_back(content);
}
}
}
void printProperties() {
std::cout << "XML Version: " << (xmlVer.empty() ? "N/A" : xmlVer) << std::endl;
std::cout << "Encoding: " << (encoding.empty() ? "N/A" : encoding) << std::endl;
std::cout << "DOCTYPE Public Identifier: " << (pubId.empty() ? "N/A" : pubId) << std::endl;
std::cout << "DOCTYPE System Identifier: " << (sysId.empty() ? "N/A" : sysId) << std::endl;
std::cout << "X3D Profile: " << (profile.empty() ? "N/A" : profile) << std::endl;
std::cout << "X3D Version: " << (x3dVer.empty() ? "N/A" : x3dVer) << std::endl;
std::cout << "xmlns:xsd: " << (xmlnsXsd.empty() ? "N/A" : xmlnsXsd) << std::endl;
std::cout << "xsd:noNamespaceSchemaLocation: " << (schemaLoc.empty() ? "N/A" : schemaLoc) << std::endl;
for (const auto& pair : metadata) {
std::cout << pair.first << ": ";
for (size_t i = 0; i < pair.second.size(); ++i) {
if (i > 0) std::cout << ", ";
std::cout << pair.second[i];
}
std::cout << std::endl;
}
}
void write(const std::string& filename) {
std::ofstream out(filename);
out << "<?xml version=\"" << (xmlVer.empty() ? "1.0" : xmlVer) << "\" encoding=\"" << (encoding.empty() ? "UTF-8" : encoding) << "\"?>\n";
out << "<!DOCTYPE X3D PUBLIC \"" << pubId << "\" \"" << sysId << "\">\n";
out << "<X3D profile=\"" << profile << "\" version=\"" << x3dVer << "\" xmlns:xsd=\"" << xmlnsXsd << "\" xsd:noNamespaceSchemaLocation=\"" << schemaLoc << "\">\n";
out << "<head>\n";
for (const auto& pair : metadata) {
for (const auto& val : pair.second) {
out << "<meta name=\"" << pair.first << "\" content=\"" << val << "\"/>\n";
}
}
out << "</head>\n<Scene></Scene>\n</X3D>";
out.close();
}
};
// Example usage:
// int main() {
// X3DParser parser;
// parser.load("example.x3d");
// parser.printProperties();
// parser.write("output.x3d");
// return 0;
// }