The Recordset utility allows the storage and retrieval of objects with similar properties.
Getting Started
To include the source files for Recordset and its dependencies, first load the YUI seed file if you haven't already loaded it.
<script src="http://yui.yahooapis.com/3.18.1/build/yui/yui-min.js"></script>
Next, create a new YUI instance for your application and populate it with the
modules you need by specifying them as arguments to the YUI().use()
method.
YUI will automatically load any dependencies required by the modules you
specify.
<script> // Create a new YUI instance and populate it with the required modules. YUI().use('recordset', function (Y) { // Recordset is available and ready for use. Add implementation // code here. }); </script>
For more information on creating YUI instances and on the
use()
method, see the
documentation for the YUI Global Object.
Using Recordsets
Recordset basics
A Recordset in its simplest form is a collection of records, where records can be considered to be object literals. Recordset allows the user to handle this collection of records with a consistent API.
Recordset augments the functionality of Y.Arraylist
but goes a
step further, by allowing the developer to quickly store and retrieve
objects with similar properties. Additional submodules can be plugged into
a Y.Recordset
instance to enable sorting, filtering and
indexing by specific keys.
Initializing a Recordset is straight-forward:
YUI().use("recordset-base", function(Y) { var data = [ {a:3, b:2, c:1}, {a:9, b:8, c:7}, {a:1, b:2, c:3} ], //Recordset is created with the objects from the data array myRecordset = new Y.Recordset({records: data}), //Empty Recordsets can also be created anEmptyRecordset = new Y.Recordset(); });
Adding, Removing, Updating and Emptying
A Y.Recordset
can be filled with a single, or an array of
object literals. Under the hood, Recordset will convert these objects into
record
instances - essentially creating a light wrapper around
them.
More information on performing operations on Recordset can be seen the the
documentation for the
recordset-base
sub-module.
Adding Records
var data = [ {key:"a", label:"Column A"}, {key:"b", label:"Column B"}, {key:"c", label:"Column C"} ], myRecordset = new Y.Recordset({records:data}); //Adding a single record to the end of a Recordset myRecordset.add({key:"d", label:"Column D"}); //Adding multiple records at the 2nd index of the Recordset myRecordset.add([ {key:"e", label:"Column E"}, {key:"f", label:"Column F"} ], 2);
Removing Records
var data = [ {key:"a", label:"Column A"}, {key:"b", label:"Column B"}, {key:"c", label:"Column C"} ], myRecordset = new Y.Recordset({records:data}); //removes the record stored at index 2 (in this case {key:"c", label:"Column C"} is removed) myRecordset.remove(2); //Removes 2 records starting at index zero myRecordset.remove(0,2);
Updating Records
var data = [ {key:"a", label:"Column A"}, {key:"b", label:"Column B"}, {key:"c", label:"Column C"} ], myRecordset = new Y.Recordset({records:data}); //overwite the record at index 2 with the following record myRecordset.update({key:"d", label:"Column D"}, 2); //You can also update multiple records at a time. //Here we are updating indices 0 and 1 of the Recordset with the corresponding two objects. myRecordset.update([ {key:"e", label:"Column E"}, {key: "f", label: "Column F"} ], 0);
Emptying a Recordset
var data = [ {key:"a", label:"Column A"}, {key:"b", label:"Column B"}, {key:"c", label:"Column C"} ], myRecordset = new Y.Recordset({records:data}); myRecordset.empty();
Events
The Recordset Utility fires custom events in addition attribute change events. Details on these events are shown below. The sub-module responsible for firing each event is represented in square braces.
Event [sub-module] | Payload |
---|---|
add [base] |
added: an array of new records that were added (can contain a single record) index: index that the addition started at |
remove [base] |
removed: an array of records that were removed (can contain a single record) index: index that the removals started at range: range of records that were removed |
update [base] |
updated: an array of records that updated (added to the Recordset) index: index that the updates started at range: range of records that were updated |
empty [base] |
Empty object bag |
change [base] |
Empty object bag, fired whenever records in the Recordset change (ie: they are added, removed, updated, or emptied) |
sort [sort] |
field: A string representing the key to sort by desc: Boolean representing whether sorting order is descending sorter: The comparison function being used to sort |
Sorting
The RecordsetSort
plugin allows a Recordset to have default
and custom sorting functionality. Various helper methods and attributes are
provided. A brief listing is shown below. Refer to the documentation for
the
RecordsetSort
plugin to see code snippets.
sort(key,desc,function [optional])
-
Sorts a Recordset by the value in the provided key. Recordset is
sorted in descending order if
desc
is truthy. Optional custom comparison function can be supplied to sort by. resort()
- Resorts a Recordset using last-used sorting arguments
reverse()
- Reverses the Recordset without performing any sort operations
flip()
- Resorts the Recordset in ascending order if the last sort arguments specified descending, and vice versa.
lastSortProperties Attribute
-
An object bag with
field
,desc
andsorter
keys listing the last-used arguments to sort by. isSorted Attribute
- A boolean representing if the Recordset is in a sorted state.
Filtering
The RecordsetFilter
plugin allows a Recordset to be filtered,
and returns subsets of that Recordset (as a separate Recordset instance).
Refer to the documentation for the
RecordsetFilter
plugin to see code snippets.
filter(key or function, value)
- If a key/value pair is passed in, returns a Recordset with records that match the key/value pair. Supports a custom function for more advanced filtering. The custom function must return a boolean.
reject(function)
-
The inverse of filter. Executes the supplied function on each item.
Returns a new Recordset containing the items that the supplied
function returned
false
for. grep(pattern)
- Iterates over the Recordset, returning a new Recordset of all the elements that match the supplied regular expression
Indexing
In the recordset-base
submodule, the table
attribute stores an associative array that hashes all records within the
Recordset by their unique YUIDs. This table is kept in sync with the
Recordset through custom events.
To allow for customization when indexing, there is the
RecordsetIndexer
plugin. Refer to the RecordsetIndexer
documentation for full details.
createTable(key)
- Creates a hash table with the given key with all existing records in the Recordset.
getTable(key)
- Get a hash table that hashes records by a given key.
hashTables
attribute- An object bag, with each property referring to a user-created hash table.