Open Patterns is repository of common application functionality
patterns allowing subsystems and applications provide often
required but difficult to implement features with a minimal
effort. Included functionality patterns usually cover all
application tiers providing reusable persistence implementation,
business logic and user interface design elements.
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This pattern, also known as paged data access pattern,
allows accessing large amount of data in relational database
in small chunks. It allows retrieving data page by page or
directly accessing a specified page. Page represents several
data items retrieved and displayed together. The page size
is user and system configurable.
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If for example your application manages large amount of
items to sell, this pattern allows you to display to user
20 of them at a time and then let user browse the rest of
the items either page by page or jump directly to a certain
page. All of this without extensive coding on your part.
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The pattern allows to define what columns of your data
object should be retrieved, so there is no need to return
the entire record all the time. Retrieved columns may vary
from request to request.
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The pattern supports server side and client side sorting
and filtering using configurable rules and conditions. It
is easy to specify either in your code or in the user
interface what data to display, how to display them and how
should they be sorted.
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Works efficiently on all
supported databases and no SQL coding is required. All
queries are provided out of the box.
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Provides ready to use dynamic user interface for web based
applications as well as asynchronous data loading for
desktop applications. With minimal coding effort you can
create web pages that display portion of your data together
with navigation controls allowing user to access the rest of
the data.
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To make the implementation easier, this pattern provides
persistence tier classes such us
database
schema classes to generate queries to retrieve data
from the database page by page and
database
factory classes to execute the generated queries and
fetch the data. For business logic tier it provides
fully functional
controller
allowing to access previous, next or specific page with your
data or change page definition settings. For user interface
tier this pattern provides reusable
servlet that
processes requests from an user interface and loads and
displays the desired set of data. This pattern also provides
JSP page elements
to easily generate controls that allow user navigate the data.
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See how to use this
pattern.
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Mapped data pattern allows creation, access and management
of relations between data objects in a generic way. It allows
maintaining multiple types of links between the same data
elements and supports one to one, one to many and many to
many relations. Additional data attributes may be associated
with each link. Provided API lets your application
efficiently retrieve related items.
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If you are for example developing application to sell
electronic equipment and you have two related items, such
as flat screen TV and TV stand, you can easily create link
between these two data objects. This allows your application
show related items user might be interested in. You can
associate type with each link to distinguish for example
between items that complement each other or items that can
replace each other. You can also attach certain amount of
data to the link, such as percentage discount the user will
receive if he buys the items together.
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The patterns works efficiently on
all supported databases
with minimal coding effort required to integrate with
existing subsystems. No SQL coding is required.
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This pattern provides data object class representing the
link between your data elements as well as fully functional
database
schema classes for all supported databases and
database
factory class to create, modify and access the data
mappings. The business logic tier is supported by
controller
providing flexible methods allowing the rest of your
application or subsystems to manage and access relations
among your data objects.
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See how to use this
pattern.
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Ordered data pattern simplifies development of subsystems
that have to manage order of their data objects either by
automatically keeping the data object in certain order or
by letting user define and change order of the data objects.
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If your application lets user create for example wishlist
of items he may want to purchase, the user may want to
prioritize the list in an order, in which he would like to
receive them. This pattern lets you easily create user
interface that allows user to reorder the items as well as
provide backend implementation that allows your application
to easily recognize when an order has changed and persist
the changed order.
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The pattern defines simple data object interfaces for
accessing and modifying the order. It provides sets of
utility classes for comparison or ordered data objects as
well as for detection when order of data objects has changed.
The utility classes also simplify coding of web clients that
need to propagate order of the data objects from the server
to the client and vice versa. At last, the pattern provides
set of custom JSP tags and JavaScript methods to speed up
development of web user interface for ordering of data.
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See how to use
this pattern.
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Scrollable table pattern is the easiest way how to add to
the web pages HTML tables that can behave just like the
desktop alternatives. The table has body that can scroll
vertically and horizontally depending on the content size.
The header and footer of the table are always visible and
never scroll outside of the view. The header of the table
is synchronized with the body and scrolls horizontally to
reveal hidden columns whenever the body of the table is
scrolled.
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The pattern supports selection of table rows either using
keyboard or mouse as user would normally do in desktop
application or using check boxes as it is common in web
pages. It also provides JavaScript notification when
selection in the table changes or when user clicks on a
link in the table row.
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The pattern provides templating engine layout to easily
create scrollable table that fills the entire page as well
as it provides set of custom JSP tags that allow to create
pages that contain one or more scrollable tables together
with other content.
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See how to use
this pattern.
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Tabbed dialog pattern is the simplest way how to enhance the
web pages with tabbed dialogs. The HTML tabbed dialogs
created using this pattern behave exactly like their
desktop alternatives. Tabs allow presenting data and gather
information split into multiple areas. Only one of these
areas called tabs is visible at any given time.
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The pattern provides set of custom JSP tags that represent
the tabbed dialog, tab headers, individual tabs, hidden tabs
that can be displayed programmatically, support for mnemonics
for tab headers, JavaScript notification when tabs are
switched or closed and more.
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See how to use
this pattern.
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Dialog layout pattern simplifies creation of web based
dialogs by allowing to easily arrange controls aligned to
single or multiple columns. Each control can have associated
label with full support for mnemonics. The label also acts
as a trigger to display context help associated with the
control. Each control can be also accessed by a hotkey.
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The custom JSP tags provided by this pattern simplify the
coding of the web base dialogs by tying together various
elements each controls consists of: control labels, control
itself, context help, etc.
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The pattern provides custom JSP tags for the common controls
such as edit fields, text areas, checkboxes and lists as
well as more advanced controls such as double selection list,
dynamic list, etc.
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See how to use
this pattern.
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Background task pattern simplifies development of
background or system tasks, which are tasks that are
executed by the subsystem or application independently of
user activities.
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If your application for example allows user to purchase
items online, you may want to have an automated task that
monitors the inventory levels and if the inventory decreases
bellow certain threshold, your background task may send an
reorder request to your suppliers. The pattern allows you
to easily develop a background task that can have multiple
instances running concurrently and each one of them can be
automatically started and configured by your application.
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This pattern provides data object interfaces and utility
classes for configuring background tasks as well as web
application listeners for smooth integration of background
tasks with web applications.
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See how to use
this pattern.
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Over 32 automated JUnit and visual web tests.
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All source code meticulously code reviewed.
