File yui3/src/recordset/js/recordset-base.js
/**
The Recordset utility provides a standard way for dealing with
a collection of similar objects.
@module recordset
@main recordset
@submodule recordset-base
**/
var ArrayList = Y.ArrayList,
Lang = Y.Lang,
/**
The Recordset utility provides a standard way for dealing with
a collection of similar objects.
Provides the base Recordset implementation, which can be extended to add
additional functionality, such as custom indexing. sorting, and filtering.
@class Recordset
@extends Base
@uses ArrayList
@param config {Object} Configuration object with initial attribute values
@constructor
**/
Recordset = Y.Base.create('recordset', Y.Base, [], {
/**
* Publish default functions for events. Create the initial hash table.
*
* @method initializer
* @protected
*/
initializer: function() {
// The reason the conditional is needed is because of two scenarios:
// 1. Instantiating new Y.Recordset() will not go into the setter of "records", and so it is necessary to create this._items in the initializer.
// 2. Instantiating new Y.Recordset({records: [{...}]}) will call the setter of "records" and create this._items. In this case, we don't want that to be overwritten by [].
if (!this._items) {
this._items = [];
}
//set up event listener to fire events when recordset is modified in anyway
this.publish({
/**
* <p>At least one record is being added. Additional properties of
* the event are:</p>
* <dl>
* <dt>added</dt>
* <dd>Array of new records to be added</dd>
* <dt>index</dt>
* <dd>The insertion index in the Recordset's internal
* array</dd>
* </dl>
*
* <p>Preventing this event will cause the new records NOT to be
* added to the Recordset's internal collection.</p>
*
* @event add
* @preventable _defAddFn
*/
add: { defaultFn: this._defAddFn },
/**
* <p>At least one record is being removed. Additional properties of
* the event are:</p>
* <dl>
* <dt>removed</dt>
* <dd>Array of records to be removed</dd>
* <dt>range</dt>
* <dd>Number of records to be removed</dd>
* <dt>index</dt>
* <dd>The starting index in the Recordset's internal
* array from which to remove records</dd>
* </dl>
*
* <p>Preventing this event will cause the records NOT to be
* removed from the Recordset's internal collection.</p>
*
* @event remove
* @preventable _defRemoveFn
*/
remove: { defaultFn: this._defRemoveFn },
/**
* The Recordset is being flushed of all records.
*
* @event empty
* @preventable _defEmptyFn
*/
empty: { defaultFn: this._defEmptyFn },
/**
* <p>At least one record is being updated. Additional properties of
* the event are:</p>
* <dl>
* <dt>updated</dt>
* <dd>Array of records with updated values</dd>
* <dt>overwritten</dt>
* <dd>Array of current records that will be replaced</dd>
* <dt>index</dt>
* <dd>The starting index in the Recordset's internal
* array from which to update will apply</dd>
* </dl>
*
* <p>Preventing this event will cause the records NOT to be
* updated in the Recordset's internal collection.</p>
*
* @event update
* @preventable _defUpdateFn
*/
update: { defaultFn: this._defUpdateFn }
});
this._buildHashTable(this.get('key'));
this.after([
'recordsChange',
'add',
'remove',
'update',
'empty'], this._updateHash);
},
/**
* Returns the record with particular ID or index
*
* @method getRecord
* @param i {String, Number} The ID of the record if a string, or the index if a number.
* @return {Record} A Y.Record instance
*/
getRecord: function(i) {
if (Lang.isString(i)) {
return this.get('table')[i];
}
else if (Lang.isNumber(i)) {
return this._items[i];
}
return null;
},
/**
* Returns the record at a particular index
*
* @method getRecordByIndex
* @param i {Number} Index at which the required record resides
* @return {Record} A Y.Record instance
*/
getRecordByIndex: function(i) {
return this._items[i];
},
/**
* Returns a range of records beginning at particular index
*
* @method getRecordsByIndex
* @param index {Number} Index at which the required record resides
* @param range {Number} (Optional) Number of records to retrieve. The default is 1
* @return {Array} An array of Y.Record instances
*/
getRecordsByIndex: function(index, range) {
var i = 0,
returnedRecords = [];
//Range cannot take on negative values
range = (Lang.isNumber(range) && (range > 0)) ? range: 1;
for (; i < range; i++) {
returnedRecords.push(this._items[index + i]);
}
return returnedRecords;
},
/**
* Returns the length of the recordset
*
* @method getLength
* @return {Number} Number of records in the recordset
*/
getLength: function() {
return this.size();
},
/**
Gets an array of values for a data _key_ in the set's records. If no _key_
is supplied, the returned array will contain the full data object for each
record.
@method getValuesByKey
@param {String} [key] Data property to get from all records
@return {Array} An array of values for the given _key_ if supplied.
Otherwise, an array of each record's data hash.
**/
getValuesByKey: function(key) {
var i = 0,
len = this._items.length,
retVals = [];
for (; i < len; i++) {
retVals.push(this._items[i].getValue(key));
}
return retVals;
},
/**
* Adds one or more Records to the RecordSet at the given index. If index is null, then adds the Records to the end of the RecordSet.
*
* @method add
* @param {Record|Object|Array} oData A Y.Record instance, An object literal of data or an array of object literals
* @param [index] {Number} [index] Index at which to add the record(s)
* @return {Recordset} The updated recordset instance
*/
add: function(oData, index) {
var newRecords = [],
idx,
i = 0;
idx = (Lang.isNumber(index) && (index > -1)) ? index: this._items.length;
//Passing in array of object literals for oData
if (Lang.isArray(oData)) {
for (; i < oData.length; i++) {
newRecords[i] = this._changeToRecord(oData[i]);
}
} else if (Lang.isObject(oData)) {
newRecords[0] = this._changeToRecord(oData);
}
this.fire('add', {
added: newRecords,
index: idx
});
return this;
},
/**
Removes one or more Records to the RecordSet at the given index. If index
is null, then removes a single Record from the end of the RecordSet.
@method remove
@param {Number} [index] Index at which to remove the record(s) from
@param {Number} [range] Number of records to remove (including the one
at the index)
@return {Recordset} The updated recordset instance
**/
remove: function(index, range) {
var remRecords = [];
//Default is to only remove the last record - the length is always 1 greater than the last index
index = (index > -1) ? index: (this._items.length - 1);
range = (range > 0) ? range: 1;
remRecords = this._items.slice(index, (index + range));
this.fire('remove', {
removed: remRecords,
range: range,
index: index
});
//this._recordRemoved(remRecords, index);
//return ({data: remRecords, index:index});
return this;
},
/**
* Empties the recordset
*
* @method empty
* @return {Recordset} The updated recordset instance
*/
empty: function() {
this.fire('empty', {});
return this;
},
/**
Updates the recordset with the new records passed in. Overwrites existing
records when updating the index with the new records.
@method update
@param {Record|Object|Array} data A Y.Record instance, An object literal of
data or an array of object literals
@param {Number} [index] The index to start updating from.
@return {Recordset} The updated recordset instance
**/
update: function(data, index) {
var rec,
arr,
i = 0;
// Whatever is passed in, we are changing it to an array so that it can
// be easily iterated in the _defUpdateFn method
arr = (!(Lang.isArray(data))) ? [data] : data;
rec = this._items.slice(index, index + arr.length);
for (; i < arr.length; i++) {
arr[i] = this._changeToRecord(arr[i]);
}
this.fire('update', {
updated: arr,
overwritten: rec,
index: index
});
return this;
},
/**
* Default behavior for the "add" event. Adds Record instances starting from
* the index specified in `e.index`.
*
* @method _defAddFn
* @param {EventFacade} e The add event
* @private
*/
_defAddFn: function(e) {
this._items.splice.apply(this._items, [e.index, 0].concat(e.added));
},
/**
* Default behavior for the "remove" event. Removes Records from the
* internal array starting from `e.index`. By default, it will remove one
* Record. But if `e.range` is set, it will remove that many Records.
*
* @method _defRemoveFn
* @param {EventFacade} e The remove event
* @private
*/
_defRemoveFn: function(e) {
this._items.splice(e.index, e.range || 1);
},
/**
* Default behavior for the "update" event. Sets Record instances for each
* item in `e.updated` at indexes starting from `e.index`.
*
* @method _defUpdateFn
* @param {EventFacade} e The update event
* @private
*/
_defUpdateFn: function(e) {
for (var i = 0; i < e.updated.length; i++) {
this._items[e.index + i] = this._changeToRecord(e.updated[i]);
}
},
/**
* Default behavior for the "empty" event. Clears the internal array of
* Records.
*
* @method _defEmptyFn
* @param {EventFacade} e The empty event
* @private
*/
_defEmptyFn: function(e) {
this._items = [];
Y.log('empty fired');
},
/**
Updates the internal hash table.
@method _defUpdateHash
@param {EventFacade} e Event triggering the hash table update
@private
**/
_updateHash: function (e) {
var handler = "_hash",
type = e.type.replace(/.*:/,''),
newHash;
// _hashAdd, _hashRemove, _hashEmpty, etc
// Not a switch or else if setup to allow for external expansion.
handler += type.charAt(0).toUpperCase() + type.slice(1);
newHash = this[handler] &&
this[handler](this.get('table'), this.get('key'), e);
if (newHash) {
this.set('table', newHash);
}
},
/**
Regenerates the hash table from the current internal array of Records.
@method _hashRecordsChange
@param {Object} hash The hash map before replacement
@param {String} key The key by which to add items to the hash
@param {Object} e The event or object containing the items to be added.
Items are expected to be stored in an array assigned to
the `added` property.
@return {Object} The updated hash map
@private
**/
_hashRecordsChange: function (hash, key, e) {
return this._buildHashTable(key);
},
/**
Builds a hash table from the current internal array of Records.
@method _buildHashTable
@param {String} key The Record key to hash the items by
@return {Object} A new hash map of Records keyed by each Records' key
@private
**/
_buildHashTable: function (key) {
return this._hashAdd({}, key, { added: this._items });
},
/**
Adds items to the hash table. Items are the values, and the keys are the
values of the item's attribute named in the `key` parameter.
@method _hashAdd
@param {Object} hash The hash map before adding items
@param {String} key The key by which to add the items to the hash
@param {Object} e The event or object containing the items to be added.
Items are expected to be stored in an array assigned to
the `added` property.
@return {Object} The updated hash map
@private
**/
_hashAdd: function(hash, key, e) {
var items = e.added,
i, len;
for (i = 0, len = e.added.length; i < len; ++i) {
hash[items[i].get(key)] = items[i];
}
return hash;
},
/**
Removes items from the hash table.
@method _hashRemove
@param {Object} hash The hash map before removing items
@param {String} key The key by which to remove the items from the hash
@param {Object} e The event or object containing the items to be removed.
Items are expected to be stored in an array assigned to
the `removed` property.
@return {Object} The updated hash map
@private
**/
_hashRemove: function(hash, key, e) {
for (var i = e.removed.length - 1; i >= 0; --i) {
delete hash[e.removed[i].get(key)];
}
return hash;
},
/**
Updates items in the hash table.
@method _hashUpdate
@param {Object} hash The hash map before updating items
@param {String} key The key by which to update the items to the hash
@param {Object} e The event or object containing the items to be updated.
Items are expected to be stored in an array assigned to
the `updated` property. Optionally, items can be
identified for being overwritten by including them in an
array assigned to the `overwritten` property.
@return {Object} The updated hash map
@private
**/
_hashUpdate: function (hash, key, e) {
if (e.overwritten && e.overwritten.length) {
hash = this._hashRemove(hash, key, { removed: e.overwritten });
}
return this._hashAdd(hash, key, { added: e.updated });
},
/**
Clears the hash table.
@method _hashEmpty
@param {Object} hash The hash map before adding items
@param {String} key The key by which to remove the items from the hash
@param {Object} e The event or object containing the items to be removed.
Items are expected to be stored in an array assigned to
the `removed` property.
@return {Object} An empty hash
@private
**/
_hashEmpty: function() {
return {};
},
/**
* Sets up the hashtable with all the records currently in the recordset
*
* @method _initHashTable
* @private
*/
_initHashTable: function() {
return this._hashAdd({}, this.get('key'), { added: this._items || [] });
},
/**
* Helper method - it takes an object bag and converts it to a Y.Record
*
* @method _changeToRecord
* @param obj {Object|Record} Any objet literal or Y.Record instance
* @return {Record} A Record instance.
* @private
*/
_changeToRecord: function(obj) {
return (obj instanceof Y.Record) ? obj : new Y.Record({ data: obj });
},
/**
Ensures the value being set is an array of Record instances. If array items
are raw object data, they are turned into Records.
@method _setRecords
@param {Record[]|Object[]} items The Records or data Objects to store as
Records.
@return {Record[]}
**/
_setRecords: function (items) {
if (!Y.Lang.isArray(items)) {
return Y.Attribute.INVALID_VALUE;
}
var records = [],
i, len;
// FIXME: This should use the flyweight pattern if possible
for (i = 0, len = items.length; i < len; ++i) {
records[i] = this._changeToRecord(items[i]);
}
return (this._items = records);
}
}, {
ATTRS: {
/**
* An array of Records that the Recordset is storing. Passing an array
* of raw record data is also accepted. The data for each item will be
* wrapped in a Record instance.
*
* @attribute records
* @type {Record[]}
*/
records: {
// TODO: necessary? valueFn?
lazyAdd: false,
getter: function() {
// give them a copy, not the internal object
return Y.Array(this._items);
},
setter: "_setRecords"
},
/**
A hash table where the ID of the record is the key, and the record
instance is the value.
@attribute table
@type object
**/
table: {
valueFn: '_initHashTable'
},
/**
The ID to use as the key in the hash table.
@attribute key
@type string
**/
key: {
value: 'id',
readOnly: true
}
}
});
Y.augment(Recordset, ArrayList);
Y.Recordset = Recordset;