dataparser/js/dataparser-json.js

	dataparser-json.js revision 6608a5406cae6b74c06f0a501e189d1fc173dc21
0N/A/**
3909N/A * The DataParser utility provides a common configurable interface for widgets to
0N/A * parse a variety of data against a given schema.
0N/A *
0N/A * @module dataparser
0N/A */
2362N/Avar LANG = Y.Lang,
0N/A
2362N/A/**
0N/A * JSON subclass for the YUI DataParser utility.
0N/A * @class DataParser.JSON
0N/A * @extends DataParser.Base
0N/A * @static
0N/A */
0N/ADPJSON = {
0N/A
0N/A    /////////////////////////////////////////////////////////////////////////////
0N/A    //
0N/A    // DataParser.JSON static methods
0N/A    //
2362N/A    /////////////////////////////////////////////////////////////////////////////
2362N/A
2362N/A    /**
0N/A     * Utility function converts JSON locator strings into walkable paths
0N/A     *
0N/A     * @method DataParser.JSON.buildPath
0N/A     * @param locator {String} JSON value locator.
0N/A     * @return {String[]} Walkable path to data value.
0N/A     * @static
0N/A     */
0N/A    buildPath: function(locator) {
0N/A        var path = null,
0N/A            keys = [],
0N/A            i = 0;
0N/A
0N/A        if (locator) {
0N/A            // Strip the ["string keys"] and [1] array indexes
0N/A            locator = locator.
0N/A                replace(/\[(['"])(.*?)\1\]/g,
0N/A                function (x,$1,$2) {keys[i]=$2;return '.@'+(i++);}).
0N/A                replace(/\[(\d+)\]/g,
0N/A                function (x,$1) {keys[i]=parseInt($1,10)|0;return '.@'+(i++);}).
0N/A                replace(/^\./,''); // remove leading dot
0N/A
0N/A            // Validate against problematic characters.
0N/A            if (!/[^\w\.\$@]/.test(locator)) {
0N/A                path = locator.split('.');
0N/A                for (i=path.length-1; i >= 0; --i) {
0N/A                    if (path[i].charAt(0) === '@') {
1676N/A                        path[i] = keys[parseInt(path[i].substr(1),10)];
1676N/A                    }
0N/A                }
0N/A            }
0N/A            else {
0N/A                Y.log("Invalid locator: " + locator, "error", this.toString());
0N/A            }
0N/A        }
0N/A        return path;
0N/A    },
0N/A
0N/A    /**
0N/A     * Utility function to walk a path and return the value located there.
0N/A     *
0N/A     * @method DataParser.JSON.walkPath
0N/A     * @param path {String[]} Locator path.
0N/A     * @param data {String} Data to traverse.
0N/A     * @return {Object} Data value at location.
0N/A     * @static
0N/A     */
0N/A    walkPath: function (path, data) {
0N/A        var i = 0,
0N/A            len = path.length;
0N/A        for (;i<len;i++) {
0N/A            data = data[path[i]];
0N/A        }
0N/A        return data;
0N/A    },
0N/A
0N/A    /**
0N/A     * Overriding parse method traverses JSON data according to given schema.
0N/A     *
0N/A     * @method _parse
0N/A     * @param schema {Object} Schema to parse against.
0N/A     * @param data {Object} Data to parse.
0N/A     * @return {Object} Schema-parsed data.
0N/A     * @static
0N/A     * @protected
0N/A     */
0N/A    _parse: function(schema, data) {
0N/A        var data_in = (data.responseText && Y.JSON.parse(data.responseText)) || data,
0N/A            data_out = {results:[],meta:{}};
0N/A
0N/A        if(LANG.isObject(data_in) && schema) {
0N/A            // Parse results data
0N/A            data_out = this._parseResults(schema, data_in, data_out);
0N/A
0N/A            // Parse meta data
0N/A            if(LANG.isObject(schema.metaFields)) {
0N/A                data_out = this._parseMeta(schema.metaFields, data_in, data_out);
0N/A            }
0N/A        }
0N/A        else {
0N/A            Y.log("JSON data could not be parsed: " + Y.dump(data_in), "error", this.toString());
0N/A            data_out.error = true;
0N/A        }
0N/A
0N/A        return data_out;
0N/A    },
0N/A
0N/A    /**
0N/A     * Schema-parse list of results from full data
0N/A     *
0N/A     * @method _parseResults
0N/A     * @return {Array} Array of results.
0N/A     * @static
0N/A     * @protected
0N/A     */
0N/A    _parseResults: function(schema, data_in, data_out) {
0N/A        if(schema.resultsList) {
0N/A            var bError = false,
0N/A                results = [],
0N/A                path;
0N/A
0N/A            path = DPJSON.buildPath(schema.resultsList);
0N/A            if(path) {
0N/A                results = DPJSON.walkPath(path, data_in);
0N/A                if (results === undefined) {
0N/A                    bError = true;
0N/A                }
0N/A                else {
0N/A                    if(LANG.isArray(schema.fields)) {
0N/A                        if(LANG.isArray(schema.fields)) {
0N/A                            results = this._filterFieldValues(schema.fields, results);
0N/A                        }
0N/A                        else {
0N/A                            bError = true;
0N/A                        }
0N/A                    }
0N/A                }
0N/A            }
0N/A            else {
0N/A                bError = true;
0N/A            }
0N/A
0N/A            if (bError) {
0N/A                Y.log("JSON data could not be parsed: " + Y.dump(data_in), "error", this.toString());
0N/A                data_out.error = true;
0N/A            }
0N/A
0N/A            data_out.results = results;
0N/A        }
0N/A        return data_out;
0N/A    },
1676N/A
1676N/A    /**
1676N/A     * Schema-parse field data out of list of full results
1676N/A     *
1676N/A     * @method _filterFieldValues
1676N/A     * @return {Array} Array of field-filtered results.
1676N/A     * @static
1676N/A     * @protected
1676N/A     */
1676N/A    _filterFieldValues: function(fields, results) {
1676N/A        var data_out = [],
1676N/A            len = fields.length,
1676N/A            i, j,
1676N/A            field, key, path, parser,
1676N/A            simplePaths = [], complexPaths = [], fieldParsers = [],
1676N/A            result, record;
1676N/A
0N/A        // First collect hashes of simple paths, complex paths, and parsers
0N/A        for (i=0; i<len; i++) {
1676N/A            field = fields[i]; // A field can be a simple string or a hash
1676N/A            key = field.key || field; // Find the key
1676N/A
1676N/A            // Validate and store locators for later
1676N/A            path = DPJSON.buildPath(key);
1676N/A            if (path) {
1676N/A                if (path.length === 1) {
1676N/A                    simplePaths[simplePaths.length] = {key:key, path:path[0]};
1676N/A                } else {
1676N/A                    complexPaths[complexPaths.length] = {key:key, path:path};
1676N/A                }
0N/A            } else {
1676N/A                Y.log("Invalid key syntax: " + key, "warn", this.toString());
1676N/A            }
1676N/A
3480N/A            // Validate and store parsers for later
3480N/A            parser = (LANG.isFunction(field.parser)) ? field.parser : Y.DataParser[field.parser+''];
3480N/A            if (parser) {
1676N/A                fieldParsers[fieldParsers.length] = {key:key, parser:parser};
1676N/A            }
0N/A        }
1676N/A
1676N/A        // Traverse list of results, creating records of simple fields,
1676N/A        // complex fields, and applying parsers as necessary
0N/A        for (i=results.length-1; i>=0; --i) {
0N/A            record = {};
0N/A            result = results[i];
0N/A            if(result) {
0N/A                // Cycle through simpleLocators
0N/A                for (j=simplePaths.length-1; j>=0; --j) {
0N/A                    // Bug 1777850: The result might be an array instead of object
0N/A                    record[simplePaths[j].key] =
0N/A                            LANG.isUndefined(result[simplePaths[j].path]) ?
0N/A                            result[j] : result[simplePaths[j].path];
0N/A                }
0N/A
0N/A                // Cycle through complexLocators
0N/A                for (j=complexPaths.length - 1; j>=0; --j) {
0N/A                    record[complexPaths[j].key] = DPJSON.walkPath(complexPaths[j].path, result);
0N/A                }
0N/A
0N/A                // Cycle through fieldParsers
0N/A                for (j=fieldParsers.length-1; j>=0; --j) {
0N/A                    key = fieldParsers[j].key;
0N/A                    record[key] = fieldParsers[j].parser(record[key]);
0N/A                    // Safety net
0N/A                    if (LANG.isUndefined(record[key])) {
0N/A                        record[key] = null;
0N/A                    }
0N/A                }
0N/A            }
0N/A            data_out[i] = record;
0N/A        }
0N/A
0N/A        return data_out;
0N/A    },
0N/A
0N/A    /**
0N/A     * Parses results data according to schema
0N/A     *
0N/A     * @method _parseMeta
0N/A     * @return {Object} Schema-parsed meta data.
0N/A     * @static
0N/A     * @protected
0N/A     */
    _parseMeta: function(metaFields, data_in, data_out) {
        var key, path;
        for(key in metaFields) {
            if (metaFields.hasOwnProperty(key)) {
                path = DPJSON.buildPath(metaFields[key]);
                if (path && data_in) {
                    data_out.meta[key] = DPJSON.walkPath(path, data_in);
                }
            }
        }
        return data_out;
    }
};
Y.mix(DPJSON, Y.DataParser.Base);

Y.DataParser.JSON = DPJSON;