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jssource/src_files/include/javascript/yui3/build/dataschema/dataschema-json.js

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+/*
+Copyright (c) 2009, Yahoo! Inc. All rights reserved.
+Code licensed under the BSD License:
+http://developer.yahoo.net/yui/license.txt
+version: 3.0.0
+build: 1549
+*/
+YUI.add('dataschema-json', function(Y) {
+
+/**
+ * Provides a DataSchema implementation which can be used to work with JSON data.
+ *
+ * @module dataschema
+ * @submodule dataschema-json
+ */
+
+/**
+ * JSON subclass for the DataSchema Utility.
+ * @class DataSchema.JSON
+ * @extends DataSchema.Base
+ * @static
+ */
+var LANG = Y.Lang,
+
+    SchemaJSON = {
+
+        /////////////////////////////////////////////////////////////////////////////
+        //
+        // DataSchema.JSON static methods
+        //
+        /////////////////////////////////////////////////////////////////////////////
+        /**
+         * Utility function converts JSON locator strings into walkable paths
+         *
+         * @method DataSchema.JSON.getPath
+         * @param locator {String} JSON value locator.
+         * @return {String[]} Walkable path to data value.
+         * @static
+         */
+        getPath: function(locator) {
+            var path = null,
+                keys = [],
+                i = 0;
+
+            if (locator) {
+                // Strip the ["string keys"] and [1] array indexes
+                locator = locator.
+                    replace(/\[(['"])(.*?)\1\]/g,
+                    function (x,$1,$2) {keys[i]=$2;return '.@'+(i++);}).
+                    replace(/\[(\d+)\]/g,
+                    function (x,$1) {keys[i]=parseInt($1,10)|0;return '.@'+(i++);}).
+                    replace(/^\./,''); // remove leading dot
+
+                // Validate against problematic characters.
+                if (!/[^\w\.\$@]/.test(locator)) {
+                    path = locator.split('.');
+                    for (i=path.length-1; i >= 0; --i) {
+                        if (path[i].charAt(0) === '@') {
+                            path[i] = keys[parseInt(path[i].substr(1),10)];
+                        }
+                    }
+                }
+                else {
+                }
+            }
+            return path;
+        },
+
+        /**
+         * Utility function to walk a path and return the value located there.
+         *
+         * @method DataSchema.JSON.getLocationValue
+         * @param path {String[]} Locator path.
+         * @param data {String} Data to traverse.
+         * @return {Object} Data value at location.
+         * @static
+         */
+        getLocationValue: function (path, data) {
+            var i = 0,
+                len = path.length;
+            for (;i<len;i++) {
+                if(!LANG.isUndefined(data[path[i]])) {
+                    data = data[path[i]];
+                }
+                else {
+                    data = undefined;
+                    break;
+                }
+            }
+            return data;
+        },
+
+        /**
+         * Applies a given schema to given JSON data.
+         *
+         * @method apply
+         * @param schema {Object} Schema to apply.
+         * @param data {Object} JSON data.
+         * @return {Object} Schema-parsed data.
+         * @static
+         */
+        apply: function(schema, data) {
+            var data_in = data,
+                data_out = {results:[],meta:{}};
+
+            // Convert incoming JSON strings
+            if(!LANG.isObject(data)) {
+                try {
+                    data_in = Y.JSON.parse(data);
+                }
+                catch(e) {
+                    data_out.error = e;
+                    return data_out;
+                }
+            }
+
+            if(LANG.isObject(data_in) && schema) {
+                // Parse results data
+                if(!LANG.isUndefined(schema.resultListLocator)) {
+                    data_out = SchemaJSON._parseResults(schema, data_in, data_out);
+                }
+
+                // Parse meta data
+                if(!LANG.isUndefined(schema.metaFields)) {
+                    data_out = SchemaJSON._parseMeta(schema.metaFields, data_in, data_out);
+                }
+            }
+            else {
+                data_out.error = new Error("JSON schema parse failure");
+            }
+
+            return data_out;
+        },
+
+        /**
+         * Schema-parsed list of results from full data
+         *
+         * @method _parseResults
+         * @param schema {Object} Schema to parse against.
+         * @param json_in {Object} JSON to parse.
+         * @param data_out {Object} In-progress parsed data to update.
+         * @return {Object} Parsed data object.
+         * @static
+         * @protected
+         */
+        _parseResults: function(schema, json_in, data_out) {
+            var results = [],
+                path,
+                error;
+
+            if(schema.resultListLocator) {
+                path = SchemaJSON.getPath(schema.resultListLocator);
+                if(path) {
+                    results = SchemaJSON.getLocationValue(path, json_in);
+                    if (results === undefined) {
+                        data_out.results = [];
+                        error = new Error("JSON results retrieval failure");
+                    }
+                    else {
+                        if(LANG.isArray(schema.resultFields) && LANG.isArray(results)) {
+                            data_out = SchemaJSON._getFieldValues(schema.resultFields, results, data_out);
+                        }
+                        else {
+                            data_out.results = [];
+                            error = new Error("JSON Schema fields retrieval failure");
+                        }
+                    }
+                }
+                else {
+                    error = new Error("JSON Schema 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("JSON meta data retrieval failure");
+            }
+            return data_out;
+        }
+    };
+
+Y.DataSchema.JSON = Y.mix(SchemaJSON, Y.DataSchema.Base);
+
+
+
+}, '3.0.0' ,{requires:['json', 'dataschema-base']});