Extensibility: Collabra Share, Lotus Notes, and Microsoft Exchange
In this series I've looked at the basics of groupware and discussed the capabilities, installation, and administration of Collabra Share, Lotus Notes, and Microsoft Exchange. This article will focus on their extensibility.
Collabra Share
Share uses the forum metaphor for its environment (see Screen 1). Forums are collections of shared documents on a particular subject that are organized into topics or discussion threads. Forums can store a wide variety of data, including simple and rich text as well as Object Linking and Embedding (OLE) objects. Rather than generate source code or ask you to write code for your application, Share lets you manipulate properties to regulate your forum's behavior.
These properties are stored internally to Share and are accessed via the forum properties menu. Creating a forum in Share is easy: You simply click the new forum button on the library toolbar, enter a forum name, choose an icon, and click on OK. You can customize it by adding a forum description, announcement text, access policy, encryption policies, thread and message duration, and an indexing and enrollment policy. Although setting up these forums is painless, you must stay within certain limits; you don't have the flexibility offered by Exchange or Notes.
Lotus Notes
Notes is a database-centric development environment. Every application in Notes uses at least one database. Each database is represented as an icon on a user's desktop (see Screen 2). You can design Notes applications from scratch, but Lotus includes more than 25 ready-to-use templates. A template in Notes parlance is a Notes database with a predefined structure (see Screen 3). This structure can consist of forms, views, macros, etc. Templates contain no documents. Creating a Notes application is easiest when you use the templates and then customize the resulting form.
Databases: The information stored in every Notes database is organized using four basic components: Forms, Fields, Documents, and Views.
Forms--Forms define the way a document will look. Forms can contain fields, static or label text, graphics, and even special Notes objects.
Fields--A field is an area on the form that contains a single type of data. The field's type determines its content: text, rich text (including multimedia), numbers, or time and date.
Documents--A document is what you get when you enter data into a form. When you open a database, you choose a form from the Compose menu. When the form is saved, the data is stored in the database.
Views--View displays documents in tabular format. Most databases will have several views that organize information in the ways most meaningful to you. For example, you could have a database of text documents stored in a reference application. You could create a view to show documents by author, date, and time created. You could also create a view to show documents by subject and category.
Applications: These can be divided into five major categories:
Broadcast--These applications are for information that needs to be available to a large audience. They are well suited to minutes from company meetings or to data from newswire services such as the Associated Press or Reuters. The information may initially be time-critical, but it generally becomes static.
Reference--These applications are similar to broadcast applications, except that the data stored in their databases is generally used for on-line reference.
Tracking--These applications contain data that is continually updated. The data comes from a variety of sources and is updated in real-time. An example would be customer-service tracking or project-status reports.
Discussion--These applications support both structured and unstructured dialog. If you have used a bulletin-board system or a CompuServe forum, then they will be familiar to you. Some sample applications are on-line customer support and a company-feedback section.
Workflow--These applications use special features of Notes (macros, functions, formulas, etc.) to automate everyday tasks such as form-routing and batch updates. Sample applications include conference-room scheduling and automatically routing purchase requests.
Formulas: Although you generally don't have to worry about formulas, you do have to think about them when you want to customize a database. Notes formulas are similar to mathematical formulas and include variables, constants, and operators. Notes uses formulas for six purposes:
- Calculate values displayed in documents
- Validate and translate new data in documents
- Select documents for views
- Change, add, or delete data in documents
- Determine correct form for data display
- Perform an action or task
@functions: Notes uses the @functions to provide specialized calculations and actions. These @functions are similar to those in Lotus 1-2-3. Unlike number-oriented spreadsheet @functions, Notes @functions are text-oriented. There are more than 100 Notes @functions. For example:
@DocChildren--Returns the number of direct-descendant documents for a document or category
@Accessed--Determines the last date/time a document was read or edited
@DDEInitiate--Initiates a conversation with a Dynamic Data Exchange (DDE) application and returns a conversation identification
Formula Keywords: Notes also provides keywords that perform special functions within a formula. They are:
DEFAULT--Assigns a default value to a field. This can be used to assign value to a missing field in a database for the duration of any computation. DEFAULT can also be used to assign dynamic defaults to fields.
ENVIRONMENT--Assigns a particular value to an ENVIRONMENT variable: ENVIRONMENT variables are stored on a per-user basis, and the values are maintained across Notes sessions. This can be useful if you want to generate sequential numbers or pass inherited information from one database to another.
FIELD--Changes the contents of an existing field or creates new fields. Make sure you use the FIELD keyword only with fields you store in the document, not with temporary fields.
REM--Allows you to add comments to your code. As convoluted as some of these @functions get, you'll need it.
SELECT--Defines criteria to be displayed in a view, copied by replication, or processed in a macro. If you use SELECT in a formula, you eliminate the need to select all the documents in a given database.
Although Notes doesn't have as full a programming language as Visual Basic (VB), its development environment is adequate for most applications. You can develop them rapidly if you base them on the design templates. Notes really shines in its cross-platform interoperability. The functions described all work with UNIX, Macintosh, PC, and other platforms that Notes supports.
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