dataschema-json.js revision 3a38d5b7ad9ebee258ce6cb2ebe712f058ea27c5
69N/AYUI.add('dataschema-json', function(Y) {
69N/A
69N/A/**
69N/A * The DataSchema utility provides a common configurable interface for widgets to
69N/A * apply a given schema to a variety of data.
69N/A *
69N/A * @module dataschema
69N/A */
69N/Avar LANG = Y.Lang,
69N/A
69N/A/**
69N/A * JSON subclass for the YUI DataSchema utility.
69N/A * @class DataSchema.JSON
69N/A * @extends DataSchema.Base
69N/A * @static
69N/A */
69N/ASchemaJSON = {
69N/A
69N/A /////////////////////////////////////////////////////////////////////////////
69N/A //
69N/A // DataSchema.JSON static methods
69N/A //
69N/A /////////////////////////////////////////////////////////////////////////////
69N/A /**
69N/A * Returns string name.
69N/A *
69N/A * @method toString
69N/A * @return {String} String representation for this object.
69N/A */
69N/A toString: function() {
69N/A return "DataSchema.JSON";
69N/A },
69N/A
69N/A /**
69N/A * Utility function converts JSON locator strings into walkable paths
69N/A *
69N/A * @method DataSchema.JSON.getPath
69N/A * @param locator {String} JSON value locator.
69N/A * @return {String[]} Walkable path to data value.
69N/A * @static
69N/A */
69N/A getPath: function(locator) {
69N/A var path = null,
69N/A keys = [],
69N/A i = 0;
69N/A
69N/A if (locator) {
69N/A // Strip the ["string keys"] and [1] array indexes
69N/A locator = locator.
69N/A replace(/\[(['"])(.*?)\1\]/g,
69N/A function (x,$1,$2) {keys[i]=$2;return '.@'+(i++);}).
69N/A replace(/\[(\d+)\]/g,
69N/A function (x,$1) {keys[i]=parseInt($1,10)|0;return '.@'+(i++);}).
69N/A replace(/^\./,''); // remove leading dot
69N/A
69N/A // Validate against problematic characters.
69N/A if (!/[^\w\.\$@]/.test(locator)) {
69N/A path = locator.split('.');
69N/A for (i=path.length-1; i >= 0; --i) {
69N/A if (path[i].charAt(0) === '@') {
69N/A path[i] = keys[parseInt(path[i].substr(1),10)];
69N/A }
69N/A }
69N/A }
69N/A else {
69N/A }
69N/A }
69N/A return path;
69N/A },
69N/A
69N/A /**
69N/A * Utility function to walk a path and return the value located there.
69N/A *
69N/A * @method DataSchema.JSON.getLocationValue
69N/A * @param path {String[]} Locator path.
69N/A * @param data {String} Data to traverse.
72N/A * @return {Object} Data value at location.
69N/A * @static
69N/A */
69N/A getLocationValue: function (path, data) {
69N/A var i = 0,
69N/A len = path.length;
69N/A for (;i<len;i++) {
69N/A data = data[path[i]];
69N/A }
69N/A return data;
69N/A },
69N/A
69N/A /**
69N/A * Applies a given schema to given JSON data.
69N/A *
69N/A * @method apply
69N/A * @param schema {Object} Schema to apply.
69N/A * @param data {Object} JSON data.
69N/A * @return {Object} Schema-parsed data.
69N/A * @static
69N/A */
69N/A apply: function(schema, data) {
69N/A var data_in = data,
69N/A data_out = {results:[],meta:{}};
69N/A
69N/A // Convert incoming JSON strings
69N/A if(!LANG.isObject(data)) {
69N/A try {
69N/A data_in = Y.JSON.parse(data);
69N/A }
69N/A catch(e) {
69N/A data_out.error = e;
69N/A return data_out;
69N/A }
69N/A }
69N/A
69N/A if(LANG.isObject(data_in) && schema) {
69N/A // Parse results data
69N/A if(!LANG.isUndefined(schema.resultsLocator)) {
69N/A data_out = SchemaJSON._parseResults(schema, data_in, data_out);
69N/A }
69N/A
69N/A // Parse meta data
69N/A if(!LANG.isUndefined(schema.metaFields)) {
69N/A data_out = SchemaJSON._parseMeta(schema.metaFields, data_in, data_out);
69N/A }
69N/A }
69N/A else {
69N/A data_out.error = new Error(this.toString() + " Schema parse failure");
69N/A }
69N/A
69N/A return data_out;
72N/A },
72N/A
69N/A /**
69N/A * Schema-parsed list of results from full data
69N/A *
69N/A * @method _parseResults
69N/A * @param schema {Object} Schema to parse against.
69N/A * @param json_in {Object} JSON to parse.
69N/A * @param data_out {Object} In-progress parsed data to update.
69N/A * @return {Object} Parsed data object.
* @static
* @protected
*/
_parseResults: function(schema, json_in, data_out) {
var results = [],
path,
error;
if(schema.resultsLocator) {
path = SchemaJSON.getPath(schema.resultsLocator);
if(path) {
results = SchemaJSON.getLocationValue(path, json_in);
if (results === undefined) {
data_out.results = [];
error = new Error(this.toString() + " Results retrieval failure");
}
if(LANG.isArray(schema.resultsFields) && LANG.isArray(results)) {
data_out = SchemaJSON._getFieldValues(schema.resultsFields, results, data_out);
}
else {
data_out.results = [];
error = new Error(this.toString() + " Fields retrieval failure");
}
}
else {
error = new Error(this.toString() + " Results locator failure");
}
if (error) {
data_out.error = error;
}
}
return data_out;
},
/**
* Get field data values out of list of full results
*
* @method _getFieldValues
* @param fields {Array} Fields to find.
* @param array_in {Array} Results to parse.
* @param data_out {Object} In-progress parsed data to update.
* @return {Object} Parsed data object.
* @static
* @protected
*/
_getFieldValues: function(fields, array_in, data_out) {
var results = [],
len = fields.length,
i, j,
field, key, path, parser,
simplePaths = [], complexPaths = [], fieldParsers = [],
result, record;
// First collect hashes of simple paths, complex paths, and parsers
for (i=0; i<len; i++) {
field = fields[i]; // A field can be a simple string or a hash
key = field.key || field; // Find the key
// Validate and store locators for later
path = SchemaJSON.getPath(key);
if (path) {
if (path.length === 1) {
simplePaths[simplePaths.length] = {key:key, path:path[0]};
} else {
complexPaths[complexPaths.length] = {key:key, path:path};
}
} else {
}
// Validate and store parsers for later
//TODO: use Y.DataSchema.parse?
parser = (LANG.isFunction(field.parser)) ? field.parser : Y.Parsers[field.parser+''];
if (parser) {
fieldParsers[fieldParsers.length] = {key:key, parser:parser};
}
}
// Traverse list of array_in, creating records of simple fields,
// complex fields, and applying parsers as necessary
for (i=array_in.length-1; i>=0; --i) {
record = {};
result = array_in[i];
if(result) {
// Cycle through simpleLocators
for (j=simplePaths.length-1; j>=0; --j) {
// Bug 1777850: The result might be an array instead of object
record[simplePaths[j].key] = Y.DataSchema.Base.parse(
(LANG.isUndefined(result[simplePaths[j].path]) ?
result[j] : result[simplePaths[j].path]), simplePaths[j]);
}
// Cycle through complexLocators
for (j=complexPaths.length - 1; j>=0; --j) {
record[complexPaths[j].key] = Y.DataSchema.Base.parse(
(SchemaJSON.getLocationValue(complexPaths[j].path, result)), complexPaths[j] );
}
// Cycle through fieldParsers
for (j=fieldParsers.length-1; j>=0; --j) {
key = fieldParsers[j].key;
record[key] = fieldParsers[j].parser(record[key]);
// Safety net
if (LANG.isUndefined(record[key])) {
record[key] = null;
}
}
}
results[i] = record;
}
data_out.results = results;
return data_out;
},
/**
* Parses results data according to schema
*
* @method _parseMeta
* @param metaFields {Object} Metafields definitions.
* @param json_in {Object} JSON to parse.
* @param data_out {Object} In-progress parsed data to update.
* @return {Object} Schema-parsed meta data.
* @static
* @protected
*/
_parseMeta: function(metaFields, json_in, data_out) {
if(LANG.isObject(metaFields)) {
var key, path;
for(key in metaFields) {
if (metaFields.hasOwnProperty(key)) {
path = SchemaJSON.getPath(metaFields[key]);
if (path && json_in) {
data_out.meta[key] = SchemaJSON.getLocationValue(path, json_in);
}
}
}
}
else {
data_out.error = new Error(this.toString() + " Meta retrieval failure");
}
return data_out;
}
};
Y.DataSchema.JSON = Y.mix(SchemaJSON, Y.DataSchema.Base);
}, '@VERSION@' ,{requires:['dataschema-base']});