data_object Class Reference

A data abstraction object that holds methods and attributes. More...

Inheritance diagram for data_object:

Public Member Functions
	__construct ($params=null, $fetch=true)
	Constructor.
	delete ()
	Deletes this object from the database.
	get_record_data ()
	Returns object with fields and values that are defined in database.
	insert ()
	Records this object in the Database, sets its id to the returned value, and returns that value.
	load_optional_fields ()
	Makes sure all the optional fields are loaded.
	notify_changed ($deleted)
	Called immediately after the object data has been inserted, updated, or deleted in the database.
	update ()
	Updates this object in the Database, based on its object variables.
	update_from_db ()
	Using this object's id field, fetches the matching record in the DB, and looks at each variable in turn.

Static Public Member Functions
static	fetch ($params)
	Finds and returns a data_object instance based on params.
static	fetch_all ($params)
	Finds and returns all data_object instances based on params.
static	fetch_all_helper ($table, $classname, $params)
	Factory method - uses the parameters to retrieve all matching instances from the DB.
static	set_properties (&$instance, $params)
	Given an associated array or object, cycles through each key/variable and assigns the value to the corresponding variable in this object.

Public Attributes
int	$completedself
	completed status.
int	$id
array	$optional_fields = array()
	Array of optional fields with default values - usually long text information that is not always needed.
array	$required_fields = array('id')
string	$table
Array	$unique_fields = array()

Static Protected Member Functions
static	fetch_helper ($table, $classname, $params)
	Factory method - uses the parameters to retrieve matching instance from the DB.

Detailed Description

A data abstraction object that holds methods and attributes.

Copyright

2009 Catalyst IT Ltd

Author

Aaron Barnes aaron.nosp@m.b@ca.nosp@m.talys.nosp@m.t.ne.nosp@m.t.nz

License

http://www.gnu.org/copyleft/gpl.html GNU GPL v3 or later

Constructor & Destructor Documentation

__construct()

data_object::__construct	(		$params = null,
			$fetch = true )

Constructor.

Optionally (and by default) attempts to fetch corresponding row from DB.

If $fetch is not false, there are a few different things that can happen:

• true: load corresponding row from the database, using $params as the WHERE clause
• DATA_OBJECT_FETCH_BY_KEY: load corresponding row from the database, using only the $id in the WHERE clause (if set), otherwise using the columns listed in $this->unique_fields.
• array(): load corresponding row from the database, using the columns listed in this array in the WHERE clause

Parameters

array	$params	required parameters and their values for this data object
mixed	$fetch	if false, do not attempt to fetch from the database, otherwise see notes

Member Function Documentation

delete()

data_object::delete

(

)

Deletes this object from the database.

Return values

bool

success

fetch()

static data_object::fetch ( $params )

static

Finds and returns a data_object instance based on params.

This function MUST be overridden by all deriving classes.

Parameters

array

$params

associative arrays varname => value

Exceptions

coding_exception

This function MUST be overridden

Return values

data_object

instance of data_object or false if none found.

Reimplemented in completion_aggregation, completion_completion, completion_criteria_activity, completion_criteria_completion, completion_criteria_course, completion_criteria_date, completion_criteria_duration, completion_criteria_role, completion_criteria_self, and completion_criteria_unenrol.

fetch_all()

static data_object::fetch_all ( $params )

static

Finds and returns all data_object instances based on params.

This function MUST be overridden by all deriving classes.

Parameters

array

$params

associative arrays varname => value

Exceptions

coding_exception

This function MUST be overridden

Return values

array

array of data_object instances or false if none found.

Reimplemented in completion_aggregation, completion_criteria, and completion_criteria_completion.

fetch_all_helper()

static data_object::fetch_all_helper ( $table, $classname, $params )

static

Factory method - uses the parameters to retrieve all matching instances from the DB.

@final

Parameters

string	$table	The table name to fetch from
string	$classname	The class that you want the result instantiated as
array	$params	Any params required to select the desired row

Return values

mixed

array of object instances or false if not found

fetch_helper()

static data_object::fetch_helper ( $table, $classname, $params )

staticprotected

Factory method - uses the parameters to retrieve matching instance from the DB.

@final

Parameters

string	$table	The table name to fetch from
string	$classname	The class that you want the result instantiated as
array	$params	Any params required to select the desired row

Return values

object

Instance of $classname or false.

get_record_data()

data_object::get_record_data

(

)

Returns object with fields and values that are defined in database.

Return values

stdClass

insert()

data_object::insert

(

)

Records this object in the Database, sets its id to the returned value, and returns that value.

If successful this function also fetches the new object data from database and stores it in object properties.

Return values

int	PK ID if successful, false otherwise

load_optional_fields()

data_object::load_optional_fields

(

)

Makes sure all the optional fields are loaded.

If id present (==instance exists in db) fetches data from db. Defaults are used for new instances.

notify_changed()

data_object::notify_changed

(

$deleted

)

Called immediately after the object data has been inserted, updated, or deleted in the database.

Default does nothing, can be overridden to hook in special behaviour.

Parameters

bool

$deleted

Set this to true if it has been deleted.

set_properties()

static data_object::set_properties ( & $instance, $params )

static

Given an associated array or object, cycles through each key/variable and assigns the value to the corresponding variable in this object.

@final

Parameters

data_object	$instance
array	$params

update()

data_object::update

(

)

Updates this object in the Database, based on its object variables.

ID must be set.

Return values

bool

success

update_from_db()

data_object::update_from_db

(

)

Using this object's id field, fetches the matching record in the DB, and looks at each variable in turn.

If the DB has different data, the db's data is used to update the object. This is different from the update() function, which acts on the DB record based on the object.

Return values

bool	True for success, false otherwise.

Member Data Documentation

$optional_fields

array data_object::$optional_fields = array()

Array of optional fields with default values - usually long text information that is not always needed.

If you want to create an instance without optional fields use: new data_object($only_required_fields, false);

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The documentation for this class was generated from the following file:

• completion/data_object.php