/*
* $Id: src_triplestore.js.html,v 1.1 2013/06/28 16:10:02 hitoshi Exp $
* This library enables web applications to easily store triples into Web Storage.
* See Copyright for the status of this software.
* uchida@w3.org
*/
/**
* Triplestore wrapper for HTML5 WebStorage.
* @main Triplestore
* @class Triplestore
* @constructor
* @uses localStorage
*/
var Triplestore = function() {
this.st = localStorage;
this.prefixMapping = {};
this.appPrefix = "<W3C>";
this.appPrefixLen = this.appPrefix.length;
};
(function(){
resolveQName = function(prefixMapping, qname) {
if(!qname) {
return null;
}
var resolved = null;
if(isAbsoluteURI(qname)) {
resolved = qname;
} else {
var index = qname.indexOf(":");
if(index == -1) {
resolved = qname;
} else {
var prefix = qname.substr(0, index);
var iri = prefixMapping[prefix];
if(iri) {
resolved = iri + qname.substr(index + 1);
} else {
resolved = qname;
}
}
}
return resolved;
};
isAbsoluteURI = function(url_str) {
var index = url_str.indexOf("://");
return index == -1 ? false : true;
};
/**
* Sets a mapping given a mapping and a URI to map.
* @method setMapping
* @param mapping {String} mapping
* @param iri {String} iri
* @example
* st.setMapping("foaf", "http://xmlns.com/foaf/0.1/");
*/
Triplestore.prototype.setMapping = function(mapping, iri) {
this.prefixMapping[mapping] = iri;
};
/**
* Retrieves a list of DOMStrings which are IRI identifiers for
* subjects given an optional property and value to match against.
* @method getSubjects
* @param [property] {String} property
* @param [value] {String} value
* @return {Array} Sequence<DOMString>
* @example
* st.getSubjects("foaf:name", "Bob");
*/
Triplestore.prototype.getSubjects = function(property, value) {
var hasValue = function(list, value) {
for(var i = 0; list && i < list.length; i++) {
if(list[i] == value) {
return true;
}
}
return false;
};
//init
property = resolveQName(this.prefixMapping, property);
value = resolveQName(this.prefixMapping, value);
var res = [];
for(var subject in this.st) {
var props_str = this.st.getItem(subject);
var props = JSON.parse(props_str);
if(property) {
if(value) {
if(hasValue(props[property], value)) {
res.push(subject.substr(this.appPrefixLen));
}
} else {
if(props[property]) {
res.push(subject.substr(this.appPrefixLen));
}
}
} else {
for(var prop in props) {
if(!value || hasValue(props[prop], value)) {
res.push(subject.substr(this.appPrefixLen));
break;
}
}
}
}
return res;
};
/**
* Retrieves a list of DOMStrings which are IRI identifiers for
* properties given an optional subject to match against.
* @method getProperties
* @param [subject] {String} subject
* @return {Array} Sequence<DOMString>
* @example
* st.getProperties("http://sample.org/bob");
*/
Triplestore.prototype.getProperties = function(subject) {
if(subject) {
//init
subject = resolveQName(this.prefixMapping, subject);
subject = subject ? this.appPrefix + subject: null;
var props_str = this.st.getItem(subject);
var props = JSON.parse(props_str);
var res = [];
for(var prop in props) {
res.push(prop);
}
return res;
} else {
var map = {};
for(subject in this.st) {
if(subject.substr(0, this.appPrefixLen) == this.appPrefix) {
var props_str = this.st.getItem(subject);
var props = JSON.parse(props_str);
for(var prop in props) {
map[prop] = null;
}
}
}
var res = [];
for(var key in map) {
res.push(key);
}
return res;
}
};
/**
* Retrieves a list of mixed types given an optional subject
* and property to match against.
* @method getValues
* @param [subject] {String} subject
* @param [property] {String} property
* @return {Array} Sequence<any>
* @example
* st.getValues("http://sample.org/bob", "foaf:name");
*/
Triplestore.prototype.getValues = function(subject, property) {
//init
subject = resolveQName(this.prefixMapping, subject);
property = resolveQName(this.prefixMapping, property);
subject = subject ? this.appPrefix + subject: null;
var subjects = [];
if(subject) {
subjects.push(subject);
} else {
for(var subject in this.st) {
subjects.push(subject);
}
}
var res = [];
for(var i = 0; i < subjects.length; i++) {
var subject = subjects[i];
var props_str = this.st.getItem(subject);
if(props_str) {
var props = JSON.parse(props_str);
if(property) {
if(props[property]) {
res = res.concat(props[property]);
}
} else {
for(var prop in props) {
res = res.concat(props[prop]);
}
}
}
}
return res;
};
/**
* Set a triple to localStorage. The old value of the property is overwritten.
* @method set
* @param subject {String} subject
* @param property {String} property
* @param value {String} value
* @example
* st.set("http://sample.org/bob", "foaf:name", "Bob");
*/
Triplestore.prototype.set = function(subject, property, value) {
//init
subject = resolveQName(this.prefixMapping, subject);
property = resolveQName(this.prefixMapping, property);
value = resolveQName(this.prefixMapping, value);
subject = subject ? this.appPrefix + subject: null;
var props_str = this.st[subject];
if(props_str) {
var props = JSON.parse(props_str);
props[property] = new Array(value);
this.st.setItem(subject, JSON.stringify(props));
} else {
var props = {};
props[property] = new Array(value);
this.st.setItem(subject, JSON.stringify(props));
}
};
/**
* Add a triple to localStorage. If the property has already values,
* the new value is concatenated to them.
* @method add
* @param subject {String} subject
* @param property {String} property
* @param value {String} value
* @example
* st.add("http://sample.org/bob", "foaf:name", "Bob");
*/
Triplestore.prototype.add = function(subject, property, value) {
//init
subject = resolveQName(this.prefixMapping, subject);
property = resolveQName(this.prefixMapping, property);
value = resolveQName(this.prefixMapping, value);
subject = subject ? this.appPrefix + subject: null;
var props_str = this.st[subject];
if(props_str) {//exist
var props = JSON.parse(props_str);
if(props[property]) {
props[property].push(value);
} else {
props[property] = new Array(value);
}
this.st.setItem(subject, JSON.stringify(props));
} else {//not exist
var props = {};
props[property] = new Array(value);
this.st.setItem(subject, JSON.stringify(props));
}
};
/**
* Remove an subject or a property from internal storage to match against.
* @method remove
* @param [subject] {String} subject
* @param [property] {String} property
* @example
* st.remove("http://sample.org/bob", "foaf:name");
*/
Triplestore.prototype.remove = function(subject, property) {
//init
subject = resolveQName(this.prefixMapping, subject);
property = resolveQName(this.prefixMapping, property);
subject = subject ? this.appPrefix + subject: null;
if(subject) {
if(property) {/* remove the property */
var props_str = this.st[subject];
if(props_str) {
var props = JSON.parse(props_str);
delete props[property];
this.st.setItem(subject, JSON.stringify(props));
} else {
throw Error("Not found " + subject + ":" + property);
}
} else {/* remove the subject */
this.st.removeItem(subject);
}
} else {
if(property) {/* remove all matched properties */
for(var subject in this.st) {
var props_str = this.st[subject];
var props = JSON.parse(props_str);
if(props[property]) {
delete props[property];
this.st.setItem(subject, JSON.stringify(props));
}
}
} else {
this.st.clear();
}
}
};
/**
* Retrieves a Projection given a subject
* @method getProjection
* @param subject {String} subject
* @return {Projection} projection
* @example
* st.getProjection("http://sample.org/bob");
*/
Triplestore.prototype.getProjection = function(subject) {
//init
subject = resolveQName(this.prefixMapping, subject);
subject = subject ? this.appPrefix + subject: null;
var props_str = this.st[subject];
var res = null;
if(props_str) {
var props = JSON.parse(props_str);
res = new Projection(this, subject, props);
}
return res;
};
/**
* Print the content of the storage.
* @method show
*/
Triplestore.prototype.show = function() {
for(var i = 0; i < this.st.length; i++) {
var subject = this.st.key(i);
console.log(subject + ":" + this.st.getItem(subject));
}
};
/**
* <a href="http://www.w3.org/TR/rdfa-api/#projections">
* Projection</a> class.
* @class Projection
* @private
* @constructor
*/
var Projection = function(store, subject, props) {
this.store = store;
this.st = store.st;
this.prefixMapping = store.prefixMapping;
this.subject = subject;
this.props = props;
};
/**
* Retrieves the list of properties that are available on
* the Projection. Each property must be an absolute URI.
* @method getProperties
* @return {Array} sequence<String>
*/
Projection.prototype.getProperties = function(value) {
//init
value = resolveQName(this.prefixMapping, value);
var res = [];
for(var prop in this.props) {
if(value) {
if(this.props[prop] == value) {
res.push(prop);
}
} else {
res.push(prop);
}
}
return res;
};
/**
* Retrieves the subject URI of this Projection as a string,
* the value must be an absolute URI.
* @method getSubject
* @return {String}
*/
Projection.prototype.getSubject = function() {
return this.subject.substr(this.store.appPrefixLen);
};
/**
* Retrieves the first property with the given name as a
* language-native datatype.
* @method get
* @param property {String} property
* @return {String}
* @example
* projection.get("foaf:name");
*/
Projection.prototype.get = function(property) {
var values = this.getAll(property);
return values ? values[0] : null;
};
/**
* Retrieves the list of values for a property as an array
* of language-native datatypes.
* @method getAll
* @param property {String} The name of the property to retrieve
* @return {Array} sequence<String>
* @example
* st.getAll("foaf:name");
*/
Projection.prototype.getAll = function(property) {
//init
property = resolveQName(this.prefixMapping, property);
if(property) {
return this.props[property] ? this.props[property] : [];
} else {
var res = [];
for(var prop in this.props) {
res = res.concat(this.props[prop]);
}
return res;
}
};
Projection.prototype.remove = function() {
this.st.removeItem(this.subject);
};
})();
