/**
Provides a DataSchema implementation which can be used to work with JSON data.
@module dataschema
@submodule dataschema-json
**/
/**
Provides a DataSchema implementation which can be used to work with JSON data.
See the `apply` method for usage.
@class DataSchema.JSON
@extends DataSchema.Base
@static
**/
// TODO: I don't think the calls to Base.* need to be done via Base since
// Base is mixed into SchemaJSON. Investigate for later.
SchemaJSON = {
/////////////////////////////////////////////////////////////////////////////
//
// DataSchema.JSON static methods
//
/////////////////////////////////////////////////////////////////////////////
/**
* Utility function converts JSON locator strings into walkable paths
*
* @method getPath
* @param locator {String} JSON value locator.
* @return {String[]} Walkable path to data value.
* @static
*/
var path = null,
keys = [],
i = 0;
if (locator) {
// Strip the ["string keys"] and [1] array indexes
// TODO: the first two steps can probably be reduced to one with
// /\[\s*(['"])?(.*?)\1\s*\]/g, but the array indices would be
// stored as strings. This is not likely an issue.
replace(/\[\s*(['"])(.*?)\1\s*\]/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.
// should be safe. I'm not sure what makes a locator invalid.
//if (!/[^\w\.\$@]/.test(locator)) {
}
}
/*}
else {
Y.log("Invalid locator: " + locator, "error", "dataschema-json");
}
*/
}
return path;
},
/**
* Utility function to walk a path and return the value located there.
*
* @method getLocationValue
* @param path {String[]} Locator path.
* @param data {String} Data to traverse.
* @return {Object} Data value at location.
* @static
*/
var i = 0,
for (;i<len;i++) {
} else {
break;
}
}
return data;
},
/**
Applies a schema to an array of data located in a JSON structure, returning
a normalized object with results in the `results` property. Additional
information can be parsed out of the JSON for inclusion in the `meta`
property of the response object. If an error is encountered during
processing, an `error` property will be added.
The input _data_ is expected to be an object or array. If it is a string,
it will be passed through `Y.JSON.parse()`.
If _data_ contains an array of data records to normalize, specify the
_schema.resultListLocator_ as a dot separated path string just as you would
reference it in JavaScript. So if your _data_ object has a record array at
_data.response.results_, use _schema.resultListLocator_ =
"response.results". Bracket notation can also be used for array indices or
object properties (e.g. "response['results']"); This is called a "path
locator"
Field data in the result list is extracted with field identifiers in
_schema.resultFields_. Field identifiers are objects with the following
properties:
* `key` : <strong>(required)</strong> The path locator (String)
* `parser`: A function or the name of a function on `Y.Parsers` used
to convert the input value into a normalized type. Parser
functions are passed the value as input and are expected to
return a value.
If no value parsing is needed, you can use path locators (strings)
instead of field identifiers (objects) -- see example below.
If no processing of the result list array is needed, _schema.resultFields_
can be omitted; the `response.results` will point directly to the array.
If the result list contains arrays, `response.results` will contain an
array of objects with key:value pairs assuming the fields in
_schema.resultFields_ are ordered in accordance with the data array
values.
If the result list contains objects, the identified _schema.resultFields_
will be used to extract a value from those objects for the output result.
To extract additional information from the JSON, include an array of
path locators in _schema.metaFields_. The collected values will be
stored in `response.meta`.
@example
// Process array of arrays
var schema = {
resultListLocator: 'produce.fruit',
resultFields: [ 'name', 'color' ]
},
data = {
produce: {
fruit: [
[ 'Banana', 'yellow' ],
[ 'Orange', 'orange' ],
[ 'Eggplant', 'purple' ]
]
}
};
var response = Y.DataSchema.JSON.apply(schema, data);
// response.results[0] is { name: "Banana", color: "yellow" }
// Process array of objects + some metadata
schema.metaFields = [ 'lastInventory' ];
data = {
produce: {
fruit: [
{ name: 'Banana', color: 'yellow', price: '1.96' },
{ name: 'Orange', color: 'orange', price: '2.04' },
{ name: 'Eggplant', color: 'purple', price: '4.31' }
]
},
lastInventory: '2011-07-19'
};
response = Y.DataSchema.JSON.apply(schema, data);
// response.results[0] is { name: "Banana", color: "yellow" }
// response.meta.lastInventory is '2001-07-19'
// Use parsers
schema.resultFields = [
{
key: 'name',
parser: function (val) { return val.toUpperCase(); }
},
{
key: 'price',
parser: 'number' // Uses Y.Parsers.number
}
];
response = Y.DataSchema.JSON.apply(schema, data);
// Note price was converted from a numeric string to a number
// response.results[0] looks like { fruit: "BANANA", price: 1.96 }
@method apply
@param {Object} [schema] Schema to apply. Supported configuration
properties are:
@param {String} [schema.resultListLocator] Path locator for the
location of the array of records to flatten into `response.results`
@param {Array} [schema.resultFields] Field identifiers to
details.
@param {Array} [schema.metaFields] Path locators to extract extra
non-record related information from the data object.
@param {Object|Array|String} data JSON data or its string serialization.
@return {Object} An Object with properties `results` and `meta`
@static
**/
// Convert incoming JSON strings
try {
}
catch(e) {
return data_out;
}
}
// Parse results data
// Parse meta data
}
}
else {
Y.log("JSON data could not be schema-parsed: " + Y.dump(data) + " " + Y.dump(data), "error", "dataschema-json");
}
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
*/
// Fall back to treat resultListLocator as a simple key
// Or if no resultListLocator is supplied, use the input
// if no result fields are passed in, then just take
// the results array whole-hog Sometimes you're getting
// an array of strings, or want the whole object, so
// resultFields don't make sense.
} else {
}
} else if (schema.resultListLocator) {
}
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
*/
var results = [],
i, j,
// First collect hashes of simple paths, complex paths, and parsers
for (i=0; i<len; i++) {
// Validate and store locators for later
if (path) {
});
} else {
});
}
} else {
}
// Validate and store parsers for later
//TODO: use Y.DataSchema.parse?
if (parser) {
});
}
}
// Traverse list of array_in, creating records of simple fields,
// complex fields, and applying parsers as necessary
record = {};
if(result) {
// Cycle through complexLocators
path = complexPaths[j];
// Fail over keys like "foo.bar" from nested parsing
// to single token parsing if a value is found in
// results["foo.bar"]
});
// Don't try to process the path as complex
// for further results
continue;
}
}
}
// Cycle through simpleLocators
path = simplePaths[j];
// Bug 1777850: The result might be an array instead of object
}
// Cycle through fieldParsers
// Safety net
}
}
}
}
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
*/
if (isObject(metaFields)) {
for(key in metaFields) {
}
}
}
}
else {
}
return data_out;
}
};
// TODO: Y.Object + mix() might be better here