org.json.ld.EcLinkedData Maven / Gradle / Ivy
package org.json.ld;
import com.eduworks.ec.array.EcArray;
import com.eduworks.ec.array.EcObject;
import js.jsonld;
import org.stjs.javascript.*;
import org.stjs.javascript.functions.Callback1;
import org.stjs.javascript.functions.Callback2;
import org.stjs.javascript.functions.Callback3;
/**
* Represents a JSON-LD linked data object and performs serialization.
* Note: Serialization and deserialization remove parameters that begin with '@'.
* Note: This Linked Data Object is not assumed to have an @id field.
*
* @author [email protected]
* @module org.json.ld
* @class EcLinkedData
*/
public class EcLinkedData {
public static Array atProperties = JSCollections.$array("id", "type", "schema", "context", "graph");
/**
* JSON-LD @type field.
*
* @property type
* @type string
*/
public String type;
/**
* JSON-LD @context field.
*
* @property context
* @type string
*/
public String context;
/**
* Create a linked data object.
*
* @param {string} context JSON-LD Context.
* @param {string} type JSON-LD Type.
* @constructor
*/
public EcLinkedData(String context, String type) {
setContextAndType(context, type);
}
/**
* Determines which fields to serialize into @fields.
*
* @param {string} key Property name to check if it should be an @property.
* @return {boolean} True if property is in the set of atProperties.
* @internal
* @static
* @method isAtProperty
*/
public static boolean isAtProperty(String key) {
for (int i = 0; i < atProperties.$length(); i++)
if (atProperties.$get(i).equals(key))
return true;
return false;
}
/**
* Helper function to determine if a piece of data is probably a JSON
* object.
*
* @param {string} probableJson JSON to test.
* @return {boolean} True if it is probably JSON. False if not.
* @method isProbablyJson
* @static
*/
public static boolean isProbablyJson(String probableJson) {
return probableJson.trim().startsWith("{") && probableJson.trim().endsWith("}");
}
/**
* Set the JSON-LD @context and @type.
*
* @param {string} context JSON-LD Context.
* @param {string} type JSON-LD Type.
* @method setContextAndType
*/
protected void setContextAndType(String context, String type) {
this.context = context;
this.type = type;
if (type != null) {
this.type = type.replace(context, "");
if (this.type.startsWith("/"))
this.type = this.type.substring(1);
}
}
/**
* Serializes this object to JSON.
*
* @return {string} JSON formatted object (with JSON-LD fields).
* @method toJson
*/
public String toJson() {
// This method serializes the fields in alphabetical order.
// This is to prevent signature based errors.
Object o = atIfy();
return JSGlobal.JSON.stringify(o);
}
/**
* Forces Javascript to encode the object in alphabetical order in order to
* make signature based actions more viable. Also places @(at) symbols in
* front of appropriate fields.
*
* @return {Object} Serializable JSON object.
* @internal
* @method atIfy
*/
public Object atIfy() {
return atIfyObject(this);
}
protected Object atIfyArray(Array o) {
Array a = new Array();
for (int i = 0; i < o.$length(); i++) {
if (EcObject.isObject(o.$get(i))) {
if (o.$get(i) instanceof EcLinkedData)
a.$set(i, atIfyObject(o.$get(i)));
else {
a.$set(i, o.$get(i));
}
} else if (EcArray.isArray(o.$get(i)))
a.$set(i, atIfyArray((Array) o.$get(i)));
else
a.$set(i, o.$get(i));
}
return a;
}
protected Object atIfyObject(Object o) {
Array keys = new Array();
Map me = JSObjectAdapter.$properties(o);
for (String key : me) {
if (me.$get("type") != null)
if (isAtProperty(key))
key = "@" + key;
keys.push(key);
}
keys.sort(new SortFunction() {
@Override
public int $invoke(String a, String b) {
return a.compareTo(b);
}
});
Map op = JSObjectAdapter.$properties(new Object());
for (int i = 0; i < keys.$length(); i++) {
String key = keys.$get(i);
Object value = me.$get(key.replace("@", ""));
if (value != null)
if (value instanceof EcLinkedData)
value = ((EcLinkedData) value).atIfy();
else if (EcArray.isArray(value))
value = atIfyArray((Array) value);
if (value != null)
op.$put(key, value);
else
value = me.$get(key);
if (value != null)
op.$put(key, value);
}
return op;
}
/**
* Uses the object's fully qualified type name and compares it to the
* provided type.
*
* @param {string} type Fully qualified type name uri.
* @return {boolean} True if match, False if not.
* @method isA
*/
public boolean isA(String type) {
String computedType = getFullType();
return computedType.equals(type) || this.type.equals(type);
}
/**
* Uses the object's fully qualified type name and compares it to the
* provided type.
*
* @param {string[]} type Fully qualified type name uris.
* @return {boolean} True if match, False if not.
* @method isAny
*/
public boolean isAny(Array type) {
String computedType = getFullType();
if (type.$length() == 0)
return true;
for (int i = 0; i < type.$length(); i++)
if (type.$get(i).equals(computedType) || type.$get(i).equals(this.type))
return true;
return false;
}
/**
* Gets the fully qualified type name, as JSON-LD allows the "namespace" of
* the type to be defined in @context.
*
* @return {string} Fully qualified type name.
* @method getFullType
*/
public String getFullType() {
if (context == null)
return this.type;
if (this.type.indexOf("http") != -1)
return this.type;
String computedType = context;
if (EcObject.isObject(context)) {
Array typeParts = (Array) (Object) this.type.split(":");
if (typeParts.$length() == 2) {
computedType = (String) JSObjectAdapter.$get(context, typeParts.$get(0));
if (!computedType.endsWith("/"))
computedType += "/";
computedType += typeParts.$get(1);
return computedType;
} else if (JSObjectAdapter.$get(context, "@vocab") != null)
computedType = (String) JSObjectAdapter.$get(context, "@vocab");
}
if (!computedType.endsWith("/"))
computedType += "/";
computedType += this.type;
return computedType;
}
/**
* Also could be called "upcast", for those in the know.
*
* Ghetto method of copying properties from some other object. As freshly
* deserialized javascript objects do not inherently attach the functions of
* their type, it is this or factory hell.
*
* @param that The freshly deserialized object, or the object to upcast into this object.
* @method copyFrom
*/
public void copyFrom(Object that) {
Map me = JSObjectAdapter.$properties(this);
for (String key : me) {
if (JSGlobal.typeof(me.$get(key)) != "function")
me.$delete(key);
}
Map you = JSObjectAdapter.$properties(that);
for (String key : you) {
if (JSGlobal.typeof(you.$get(key)) != "function") {
if (you.$get("@type") != null)
me.$put(key.replace("@", ""), you.$get(key));
else
me.$put(key, you.$get(key));
}
}
String stripNamespace = null;
String newContext = null;
if (type != null && context != null && EcObject.isObject(context)) {
Array typeParts = (Array) (Object) this.type.split(":");
if (typeParts.$length() == 2) {
newContext = (String) JSObjectAdapter.$get(context, typeParts.$get(0));
stripNamespace = typeParts.$get(0);
if (!newContext.endsWith("/"))
newContext += "/";
} else if (JSObjectAdapter.$get(context, "@vocab") != null)
newContext = (String) JSObjectAdapter.$get(context, "@vocab");
}
if (stripNamespace != null)
for (String key : me) {
if (JSGlobal.typeof(me.$get(key)) != "function") {
if (key.startsWith(stripNamespace + ":")) {
if (EcArray.isArray(me.$get(key))) {
JSObjectAdapter.$put(me, key.replace(stripNamespace + ":", ""), Global.JSON.parse(Global.JSON.stringify(me.$get(key)).replaceAll(stripNamespace + ":", "")));
} else if (EcObject.isObject(me.$get(key))) {
JSObjectAdapter.$put(me, key.replace(stripNamespace + ":", ""), Global.JSON.parse(Global.JSON.stringify(me.$get(key)).replaceAll(stripNamespace + ":", "")));
} else
JSObjectAdapter.$put(me, key.replace(stripNamespace + ":", ""), me.$get(key));
me.$delete(key);
}
}
}
if (newContext != null)
context = newContext;
upgrade();
if (!isAny(getTypes()))
throw new RuntimeException("Incompatible type: " + getFullType());
}
public void recast(String translationContext, String targetContext, final Callback1 success, final Callback1 failure) {
final EcLinkedData me = this;
Object json = JSGlobal.JSON.parse(toJson());
if (targetContext == null)
targetContext = (String) JSObjectAdapter.$get(json, "@context");
JSObjectAdapter.$put(json, "@context", translationContext);
final String finalTargetContext = targetContext;
jsonld.expand(json, new Object(), new Callback2() {
@Override
public void $invoke(final Object error, Object actual) {
if (error != null) {
failure.$invoke((String)JSObjectAdapter.$get(error, "message"));
return;
}
jsonld.compact(actual, finalTargetContext, new Object(), new Callback3() {
@Override
public void $invoke(String s, Object o, Object o2) {
if (s != null)
{
failure.$invoke(s);
return;
}
me.copyFrom(o);
JSObjectAdapter.$put(me,"@context",finalTargetContext);
success.$invoke(me);
}
});
}
});
}
/***
* Upgrades the object to the latest version, performing transforms and the like.
*
* @method upgrade
*/
protected void upgrade() {
}
/**
* Removes the @ symbol from properties in order to make them more
* accessible in Javascript.
*
* @return {EcLinkedData} This object, with @ properties converted to @-less properties.
* @method deAtify
* @internal
*/
public EcLinkedData deAtify() {
Map me = JSObjectAdapter.$properties(this);
boolean typeFound = false;
if (me.$get("@type") != null)
typeFound = true;
for (String key : me) {
if (me.$get(key) == null) {
if (typeFound) {
Object value = me.$get(key);
if (value != null)
if (value instanceof EcLinkedData)
value = ((EcLinkedData) value).deAtify();
me.$put(key.replace("@", ""), value);
} else {
Object value = me.$get(key);
if (value != null)
if (value instanceof EcLinkedData)
value = ((EcLinkedData) value).deAtify();
me.$put(key, value);
}
}
}
return this;
}
/**
* Gets all versions of JSON-LD type strings for this type of object.
*
* @return {string[]} Array of URIs.
* @method getTypes
*/
public Array getTypes() {
Array a = new Array<>();
if (context != null && type != null) {
if (!EcObject.isObject(context)) {
String context = (!this.context.endsWith("/") ? this.context + "/" : this.context);
if (type.indexOf(context) == 0)
a.push(type);
else
a.push(context + type);
}
}
return a;
}
public void compact(String remoteContextUrl, final Callback1