WebGuide
Project: WebGuide
Author: Gerry
Stahl
Organization: L3D
Description: a collaborative
knowledge-building environment with perspectives and negotiation
Table of Contents
of Components
Index to all defined
Fields and Methods
WebGuide Components:
The Client - Server connection:
- InterfaceState:
stores current state on client side - InterfaceMgrClient:
methods to send messages to server (called from Gulch components) - InterfaceMsgDef:
definitions of message constants - InterfaceDataSerialized:
data object that is sent to server - InterfaceNetClient:
communications object to send serialized object to server - InterfaceNetServer:
communications object on server side; maintains a thread for each client - InterfaceDataSerialized:
data object for transmission back to client (same as for client) - InterfaceMsgDef:
definitions of message constants (same as for client) - InterfaceMgrServer:
methods to send messages back to client (calls DatabaseMgr, ListMgr, ChangeMgr) - InterfaceState:
stores current state on server side (copy also kept on client)
The Client components:
- GulchApp:
main program of the client (user interface) - GulchStandaloneStub:
supplement to GulchApp to create Applet or Application - GulchTabbedPane:
coordinator of Client, displaying tabs for different components - GulchPane:
template for the panes that go into GulchTabbedPane - GulchLogin:
pane for the login procedure; contains GulchLoginPane and GulchWelcomePane - GulchLoginPane:
displays controls for the login procedure, including changing spaces and passwords - GulchWelcomePane:
displays a flashscreen greeting - GulchDiscuss:
pane for the discussion forum content display; contains GulchDiscussPane and GulchTreePane - GulchDiscussPane:
displays controls for creating, editing, deleting, copying, linking notes - GulchTreePane:
displays a hierarchy of notes and controls for navigation - GulchEditing:
pane for the login procedure; contains GulchEditingPane and GulchContentPane - GulchEditingPane:
displays controls for creating and editing notes - GulchContentPane:
displays the content of notes during editing - GulchPerspectives:
pane for perspectives; contains GulchPerspectivesPane and GulchTreePane - GulchPerspectivesPane:
displays controls for creating, editing, deleting, linking perspectives - GulchTreePane:
displays a hierarchy of perspectives and controls for navigation
The Server components:
·
DatabaseMgr:
a component to encapsulate all database access, including defining (extensible)
global constants, definitions of all nodes, link relationships among nodes, and
methods for other components to access specific data.
- ListMgr:
a component to compute the content for most displays. For the highly recursive computation of visibly nodes it caches all needed data. Calls DatabaseMgr. - ChangeMgr:
a component to manage all changes to the database: edits, add, deletes, virtual copies, new perspectives, etc. Calls DatabaseMgr. - TreeDataRow:
class to define row of data for nodeTreeControl or WebTie. - TreePredicate:
class to define comparison for sorted OrderedSet of TreeDataRows. - NodeDataRow:
class to define row of data from nodes table of COLAB database. - NodePredicate:
class to define comparison for sorted OrderedSet of NodeDataRows. - LinkDataRow:
class to define row of data from links table of COLAB database. - LinkPredicate:
class to define comparison for sorted OrderedSet of LinkDataRows.
COLAB Database Schema
- nodes table:
contains basic content of application, including columns with perspectives information and rows defining system global constants.
columns:
nid -- unique row identifier
kind -- kind of node in this item
perspective -- original perspective for this item
table_id -- table with row of additional fields for this item
contents -- row of table with additional fields for this item
name -- name of this item
description -- long text description
seq -- sequence index for this item among other children of its parent
author -- logon of user who created this item
dt_create -- timestamp of when this item was created
- links table:
contains relationships among nodes, such as one is parent or edited version of another.
columns:
lid -- unique row identifier
type -- type of link in this item
perspective -- original perspective for this item
from_node -- first node in relationship
to_node -- second node in relationship
seq -- sequence index for this item among other children of its parent
author -- logon of user who created this item
dt-create -- timestamp of when this item was created
- other tables:
statements -- long textual entries in the system
people -- login and personal information about people authorized to log on
groups -- information about groups that people belong to
decisions -- votes during negotiations
websites -- ur and bookmark for web sites
books -- bibliographic information on publications
multimedia -- gifs, sounds, video, etc.
objects -- Java objects
auxtables -- definitions of fields in auxiliary tables
Details for Building an Application
- selecting a database:
DatabaseMgr includes code to connect directly through JDBC to various SQL databases: Access, Msql, MySQL. The database must have a nodes table, a links table and various supplementary tables -- all defined in a specific way. The system is extensible through the addition of more auxiliary tables and corresponding global constants. - defining standard global
constants:
The following global constants are defined in the nodes database table. This list is extensible. It is initialized by the refreshGlobals method in DatabaseMgr.
COLAB_ROOT -- the root of all system information
COLAB_ROOT_CONTENT -- the root of the hierarchy of contents
COLAB_ROOT_PERSPECTIVE -- the root of the hierarchy of perspectives
COLAB_ROOT_CATEGORY -- the root of the hierarchy of global constants
NODE_KIND -- kinds of nodes in the nodes table
LINK_TYPE -- types of links in the links table
VCOPY -- virtual copy link type
EDIT -- edited version link type
DELETE -- deleted node link type
PARENT -- child-parent relationship link type
PERSPECTIVE -- defined perspective
TABLE -- table of additional information about nodes
DISCUSSION -- kind of node for threaded discussions
STATEMENT -- kind of node for textual entry
PERSON -- kind of node for login and personal information about person authorized to log on
GROUP -- kind of node for group that people belong to
DECISION -- kind of node for vote during negotiations
WEBSITE -- kind of node for url and bookmark for web site
BOOK -- kind of node for bibliographic information on publication
MULTIMEDIA -- kind of node for gif, sound, video, etc.
OBJECT -- kind of node for Java object - building dynamic
HTML:
WebTieApplet illustrates how to build an application with dynamic HTML pages by getting the content from the lower level components of COLAB. - building a Java
applet or servlet:
WebGuideApplet illustrates how to build a Java applet or servlet using many components of COLAB.
WebGuide Permissions: buttons and display conditions
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modes: |
group perspective |
discussion (group) |
negotiation (group) |
personal perspective |
other's perspective |
comparison perspective |
archive (deleted) |
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buttons: |
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discuss |
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X |
X |
X |
X |
X |
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propose |
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X |
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vote |
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X |
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private note |
X |
X |
X |
X |
X |
X |
X |
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new note |
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X |
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edit |
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X |
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delete |
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X |
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move |
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X |
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copy |
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X |
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link |
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X |
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copy home |
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X |
X |
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X |
X |
X |
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link home |
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X |
X |
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X |
X |
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email |
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X |
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second |
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XML |
X |
X |
X |
X |
X |
X |
X |
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displays: |
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Statement |
X |
X |
X |
X |
X |
X |
w.
deleted |
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Discussion |
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X |
X |
viewer's |
owner's |
X |
w.
deleted |
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Proposal |
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X |
viewer's |
owner's |
X |
w. deleted |
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Decision |
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X |
viewer's |
owner's |
X |
w.
deleted |
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Private |
viewer's |
viewer's |
viewer's |
viewer's |
viewer's |
viewer's |
viewer's |
X = button active or note kind displayed
exceptions: Administrator can use all buttons in all perspectives; Guest cannot use Discuss, Propose, Vote buttons
The preceding table determines the perspectives in which different kinds of notes can be created or manipulated. At the top of the tree display interface are buttons for each of the "perspectives" listed across the top of the preceding table – except for "other's perspective", which is selected from a pull-down list. For each perspective, the table shows which buttons are active. These buttons create the following kinds of nodes: discuss -> Discussion, propose -> Proposal, vote -> Decision, private note -> Private, new note -> Statement (or sub-kind of Statement).
The lower part of the table shows the perspectives in which each of the kinds of notes is displayed. For instance, a viewer can always see Private notes that were authored by that viewer but can never see Private notes authored by others.
One can view all of one's authored notes in one's own personal perspective. To achieve this, Discussion notes initiated in someone else's personal perspective or in the comparison perspective are actually created in the group perspective (under special headings if the selected note does not appear in the group perspective). One's Discussion, Proposal and Decision notes are then inherited from the group perspective and are displayed in one's own home perspective (but not in other personal perspectives).
The effect of these rules is to change the effective perspectives hierarchy. The discussion and negotiation views are simply the group perspective, including the special node kinds. The archive view is the comparison perspective, including deleted notes. The viewer's individual perspective includes private notes authored by the viewer:
The Discuss Button: Discuss selected note from other's perspective or from comparison perspective: If Nid of selected note appears in group perspective, create a new node in group perspective and link it below that note in the group perspective. Else, virtual copy the selected note into the group perspective below "discussions" note and add a new note below it.