SemanticScuttle/includes/js/dojox/rpc/JsonReferencing.js

265 lines
11 KiB
JavaScript

if(!dojo._hasResource["dojox.rpc.JsonReferencing"]){ //_hasResource checks added by build. Do not use _hasResource directly in your code.
dojo._hasResource["dojox.rpc.JsonReferencing"] = true;
dojo.provide("dojox.rpc.JsonReferencing");
dojo.require("dojo.date.stamp");
dojo.require("dojo._base.Deferred");
// summary:
// Adds advanced JSON {de}serialization capabilities to the base json library.
// This enhances the capabilities of dojo.toJson and dojo.fromJson,
// adding referencing support, date handling, and other extra format handling.
// On parsing, references are resolved. When references are made to
// ids/objects that have been loaded yet, a Deferred object will be used as the
// value and as soon as a callback is added to the Deferred object, the target
// object will be loaded.
dojox.rpc._index={}; // the global map of id->object
dojox.rpc.onUpdate = function(/*Object*/ object, /* attribute-name-string */ attribute, /* any */ oldValue, /* any */ newValue){
// summary:
// This function is called when an existing object in the system is updated. Existing objects are found by id.
};
dojox.rpc.resolveJson = function(/*Object*/ root,/*Object?*/ schema){
// summary:
// Indexes and resolves references in the JSON object.
// A JSON Schema object that can be used to advise the handling of the JSON (defining ids, date properties, urls, etc)
//
// root:
// The root object of the object graph to be processed
//
// schema: A JSON Schema object that can be used to advise the parsing of the JSON (defining ids, date properties, urls, etc) //
// Currently this provides a means for context based id handling
//
// return:
// An object, the result of the processing
var ref,reWalk=[];
function makeIdInfo(schema){ // find out what attribute and what id prefix to use
if (schema){
var attr;
if (!(attr = schema._idAttr)){
for (var i in schema.properties){
if (schema.properties[i].unique){
schema._idAttr = attr = i;
}
}
}
if (attr || schema._idPrefix){
return {attr:attr || 'id',prefix:schema._idPrefix};
}
}
return false;
}
function walk(it,stop,schema,idInfo,defaultId){
// this walks the new graph, resolving references and making other changes
var val,i;
var id = it[idInfo.attr];
id = (id && (idInfo.prefix + id)) || defaultId; // if there is an id, prefix it, otherwise inherit
var target = it;
if (id){ // if there is an id available...
it._id = id;
if (dojox.rpc._index[id]){ // if the id already exists in the system, we should use the existing object, and just update it
target = dojox.rpc._index[id];
delete target.$ref; // remove this artifact
}
dojox.rpc._index[id] = target; // add the prefix, set _id, and index it
if (schema && dojox.validate && dojox.validate.jsonSchema){ // if json schema is activated, we can load it in the registry of instance schemas map
dojox.validate.jsonSchema._schemas[id] = schema;
}
}
for (i in it){
if (it.hasOwnProperty(i) && (typeof (val=it[i]) =='object') && val){
ref=val.$ref;
if (ref){ // a reference was found
var stripped = ref.replace(/\\./g, '@').replace(/"[^"\\\n\r]*"/g, '');// trim it
if(/[\w\[\]\.\$ \/\r\n\t]/.test(stripped) && !/=|((^|\W)new\W)/.test(stripped)){ // make sure it is a safe reference
var path = ref.match(/(^\.*[^\.\[]+)([\.\[].*)?/); // divide along the path
if ((ref=path[1]=='$' ? root:dojox.rpc._index[new dojo._Url(idInfo.prefix,path[1])]) && // a $ indicates to start with the root, otherwise start with an id
(ref = path[2] ? eval('ref' + path[2]) : ref)){// starting point was found, use eval to resolve remaining property references
// otherwise, no starting point was found (id not found), if stop is set, it does not exist, we have
// unloaded reference, if stop is not set, it may be in a part of the graph not walked yet,
// we will wait for the second loop
val = ref;
}
else{
if (!stop){
if (!rewalking)
reWalk.push(it); // we need to rewalk it to resolve references
var rewalking = true; // we only want to add it once
}
else {
ref = val.$ref;
val = new dojo.Deferred();
val._id = idInfo.prefix + ref;
(function(val,ref){
var connectId = dojo.connect(val,"addCallbacks",function(){
dojo.disconnect(connectId);
dojox.rpc.services[idInfo.prefix.substring(0,idInfo.prefix.length-1)](ref) // otherwise call by looking up the service
.addCallback(dojo.hitch(val,val.callback));
});
})(val,ref);
}
}
}
}
else {
if (!stop){ // if we are in stop, that means we are in the second loop, and we only need to check this current one,
// further walking may lead down circular loops
var valSchema = val.schema || // a schema can be self-defined by the object,
(schema && schema.properties && schema.properties[i]); // or it can from the schema sub-object definition
if (valSchema){
idInfo = makeIdInfo(valSchema)||idInfo;
}
val = walk(val,reWalk==it,valSchema,idInfo,id && (id + ('[' + dojo._escapeString(i) + ']')));
}
}
}
if (dojo.isString(val) && schema && schema.properties && schema.properties[i] && schema.properties[i].format=='date-time'){// parse the date string
val = dojo.date.stamp.fromISOString(val); // create a date object
}
it[i] = val;
var old = target[i];
if (val !== old){ // only update if it changed
target[i] = val; // update the target
propertyChange(i,old,val);
}
}
function propertyChange(key,old,newValue){
setTimeout(function(){
dojox.rpc.onUpdate(target,i,old,newValue); // call the listener for each update
});
}
if (target != it){ // this means we are updating, we need to remove deleted
for (i in target){
if (!it.hasOwnProperty(i) && i != '_id' && !(target instanceof Array && isNaN(i))){
propertyChange(i,target[i],undefined);
delete target[i];
}
}
}
return target;
}
var idInfo = makeIdInfo(schema)||{attr:'id',prefix:''};
if (!root){ return root; }
root = walk(root,false,schema,idInfo,dojox._newId && (new dojo._Url(idInfo.prefix,dojox._newId) +'')); // do the main walk through
walk(reWalk,false,schema,idInfo); // re walk any parts that were not able to resolve references on the first round
return root;
};
dojox.rpc.fromJson = function(/*String*/ str,/*Object?*/ schema){
// summary:
// evaluates the passed string-form of a JSON object.
// A JSON Schema object that can be used to advise the parsing of the JSON (defining ids, date properties, urls, etc)
// which may defined by setting dojox.currentSchema to the current schema you want to use for this evaluation
//
// json:
// a string literal of a JSON item, for instance:
// '{ "foo": [ "bar", 1, { "baz": "thud" } ] }'
// schema: A JSON Schema object that can be used to advise the parsing of the JSON (defining ids, date properties, urls, etc) //
// Currently this provides a means for context based id handling
//
// return:
// An object, the result of the evaluation
root = eval('(' + str + ')'); // do the eval
if (root){
return this.resolveJson(root,schema);
}
return root;
}
dojox.rpc.toJson = function(/*Object*/ it, /*Boolean?*/ prettyPrint, /*Object?*/ schema){
// summary:
// Create a JSON serialization of an object.
// This has support for referencing, including circular references, duplicate references, and out-of-message references
// id and path-based referencing is supported as well and is based on http://www.json.com/2007/10/19/json-referencing-proposal-and-library/.
//
// it:
// an object to be serialized.
//
// prettyPrint:
// if true, we indent objects and arrays to make the output prettier.
// The variable dojo.toJsonIndentStr is used as the indent string
// -- to use something other than the default (tab),
// change that variable before calling dojo.toJson().
//
// schema: A JSON Schema object that can be used to advise the parsing of the JSON (defining ids, date properties, urls, etc) //
// Currently this provides a means for context based id handling
//
// return:
// a String representing the serialized version of the passed object.
var idPrefix = (schema&& schema._idPrefix) || ''; // the id prefix for this context
var paths={};
function serialize(it,path,_indentStr){
if (it && dojo.isObject(it)){
var value;
if (it instanceof Date){ // properly serialize dates
return '"' + dojo.date.stamp.toISOString(it,{zulu:true}) + '"';
}
var id = it._id;
if (id){ // we found an identifiable object, we will just serialize a reference to it... unless it is the root
if (path != '$'){
return serialize({$ref:id.charAt(0)=='$' ? id : // a pure path based reference, leave it alone
id.substring(0,idPrefix.length)==idPrefix ? // see if the reference is in the current context
id.substring(idPrefix.length): // a reference with a prefix matching the current context, the prefix should be removed
'../' + id});// a reference to a different context, assume relative url based referencing
}
path = id;
}
else {
it._id = path; // we will create path ids for other objects in case they are circular
paths[path] = it;// save it here so they can be deleted at the end
}
_indentStr = _indentStr || "";
var nextIndent = prettyPrint ? _indentStr + dojo.toJsonIndentStr : "";
var newLine = prettyPrint ? "\n" : "";
var sep = prettyPrint ? " " : "";
if (it instanceof Array){
var res = dojo.map(it, function(obj,i){
var val = serialize(obj, path + '[' + i + ']', nextIndent);
if(!dojo.isString(val)){
val = "undefined";
}
return newLine + nextIndent + val;
});
return "[" + res.join("," + sep) + newLine + _indentStr + "]";
}
var output = [];
for(var i in it){
var keyStr;
if(typeof i == "number"){
keyStr = '"' + i + '"';
}else if(dojo.isString(i) && i != '_id'){
keyStr = dojo._escapeString(i);
}else{
// skip non-string or number keys
continue;
}
var val = serialize(it[i],path+(i.match(/^[a-zA-Z]\w*$/) ? // can we use simple .property syntax?
('.' + i) : // yes, otherwise we have to escape it
('[' + dojo._escapeString(i) + ']')),nextIndent);
if(!dojo.isString(val)){
// skip non-serializable values
continue;
}
output.push(newLine + nextIndent + keyStr + ":" + sep + val);
}
return "{" + output.join("," + sep) + newLine + _indentStr + "}";
}
return dojo.toJson(it); // use the default serializer for primitives
}
var json = serialize(it,'$','');
for (i in paths){ // cleanup the temporary path-generated ids
delete paths[i]._id;
}
return json;
}
}