System and Software Architecture Description (SSAD)

Transcription

1 System and Software Architecture Description (SSAD) Early Medieval East Asian Timeline Team 9 Daniel Link Ainsley Chong Priyanka Shetty Aarti Kumar Gupta Abdullah Alkahtani Byron Robert Chan System Architect Project Manager Builder Tester Trainer Quality Focal Point 11/18/2012

2 Version History Date Author Version Changes made Rationale 10/09/09 DL 1.0 Initial version Initial version for Core Foundations Commitment Package 10/16/09 DL 1.1 Added to section 2 and 3 according to Foundations Commitment Package Valuation phase 10/20/09 DL 2.0 Reworked most parts Architecture Review Board 10/28/09 DL 3.0 Corrected errors pointed out in ARB; Reworked the document sections that had to be changed due to our switch from Use NDI to Architected Agile architecture 11/11/09 DL 4.0 Corrected document according to evaluation of Foundations Commitment Package 11/23/09 DL 5.0 Reworked most parts, added process realization diagrams, changed underlying operating system from Linux to Windows Server /02/2009 DL 6.0 Updated most UML diagrams, added sequence diagrams and class diagram 12/07/2009 DL 7.0 Changed Artifacts and Information diagram, Use Cases Overview and Login Sequence Diagram 12/13/2009 DL 7.5 Changed sequence diagram for List Submissions / Recent Changes 2/8/2010 DL 8.0 Made language more clear throughout document Incorporated actionable fixes from DCR ARB comments and peer reviews 2/11/2010 DL 8.5 Changed some diagrams to landscape perspective Fixed bugs from Bugzilla 4/5/2010 DL 9.5 Incorporated changes suggested at RDCR ARB 4/28/2010 DL 10.0 Deleted "Submission Preview" use case Foundations Commitment Package Response to evaluation of Foundations Commitment Package Development Commitment Package Development Commitment Architecture Review Board ARB comments Bugzilla bugs from IIV&V; archiving Re-baselined Development Commitment Review Draft Re-baselined Development Commitment Architecture Review Board IOC package SSAD_IOC2_S10b_T09_V10.0 ii 11/18/12

3 Table of Contents System and Software Architecture Description (SSAD)... i Version History... ii Table of Contents... iii Table of Tables... iv Table of Figures... vi 1. Introduction Purpose of the SSAD Status of the SSAD System Analysis System Analysis Overview System Analysis Rationale Technology-Independent Model Technology-Specific System Design Design Overview Design Rationale Architectural Styles, Patterns and Frameworks SSAD_IOC2_S10b_T09_V10.0 iii 11/18/12

4 Table of Tables Table 1: Actors Summary... 4 Table 2: Artifacts and Information Summary... 6 Table 3: Process Description - Request contributor account... 8 Table 4: Typical Course of Action - Request contributor account... 8 Table 5: Alternate Course of Action - Request contributor account... 9 Table 6: Alternate Course of Action - Request contributor account... 9 Table 7: Exceptional Course of Action - Request contributor account... 9 Table 8: Exceptional Course of Action - Request contributor account Table 9: Process Description - Manage contributor accounts Table 10: Typical Course of Action - Manage contributor accounts Table 11: Typical Course of Action - Manage contributor accounts Table 12: Typical Course of Action - Manage contributor accounts Table 13: Alternate Course of Action - Manage contributor accounts Table 14: Process Description - Manage moderator accounts Table 15: Typical Course of Action - Manage moderator accounts Table 16: Typical Course of Action - Manage moderator accounts Table 17: Alternate Course of Action - Manage moderator accounts Table 18: Process Description - Login Table 19: Typical Course of Action - Login Table 20: Alternate Course of Action - Login Table 21: Alternate Course of Action - Login Table 22: Exceptional Course of Action - Login Table 23: Process Description - Logout Table 24: Typical Course of Action - Logout Table 25: Process Description - Edit Account Information Table 26: Typical Course of Action - Edit Account Information Table 27: Alternate Course of Action - Edit Account Information Table 28: Exceptional Course of Action - Edit Account Information SSAD_IOC2_S10b_T09_V10.0 iv 11/18/12

5 Table 29: Process Description - List Submissions / Recent Changes Table 30: Typical Course of Action - List Submissions / Recent Changes Table 31: Process Description Table 32: Typical Course of Action Table 33: Alternate Course of Action Table 34: Alternate Course of Action Table 35: Process Description - Comment on article Table 36: Typical Course of Action - Comment on article Table 37: Exceptional Course of Action - Comment on article Table 40: Process Description - Edit Article Table 41: Typical Course of Action - Edit Article Table 43: Exceptional Course of Action - Edit Article Table 44: Process Description Table 45: Typical Course of Action - Add Source Table 47: Exceptional Course of Action - Add Source Table 48: Process Description Table 49: Typical Course of Action - Modify Source Table 51: Exceptional Course of Action Table 52: Process Description Table 53: Typical Course of Action Table 54: Alternate Course of Action Table 55: Alternate Course of Action Table 56: Hardware Component Description Table 57: Software Component Description Table 58: Supporting Software Component Description Table 59: Design Class Description Table 60: Architectural Styles, Patterns, and Frameworks SSAD_IOC2_S10b_T09_V10.0 v 11/18/12

6 Table of Figures Figure 1: System Context Diagram... 3 Figure 2: Artifacts and Information Diagram... 5 Figure 3: Process Diagram... 7 Figure 4: Hardware Component Class Diagram Figure 5: Software Component Class Diagram Figure 6: Deployment Diagram Figure 7: Design Class Diagram Figure 8: Login Class Diagram Figure 9: Process Realization Diagram - Login Figure 10: Process Realization Diagram - Read Article Figure 11: Process Realization Diagram - List Submissions / Recent Changes Figure 12: istudio diagram of the new system SSAD_IOC2_S10b_T09_V10.0 vi 11/18/12

7 1. Introduction 1.1 Purpose of the SSAD The purpose of the System and Software Architecture Description is to demonstrate to developers and operational stakeholders how the system to be built will operate and what its operations are. It therefore shows where the system will be situated with relation to others, what functionalities it will have, what data will flow in out of it as well as what is kept; furthermore, what its components will be and how they will interact. A sincere attempt is made to make the language of this document understandable to all stakeholders. 1.2 Status of the SSAD The SSAD is being submitted for the Initial Operational Capacity Package. Input from the Re-baselined Development Commitment Review Architecture Review Board has been processed. The project is in the Development phase and minor changes of the implementation are reflected in the architecture. SSAD_IOC2_S10b_T09_V /18/12

8 2. System Analysis 2.1 System Analysis Overview The main purposes of our new additions to and extensions of the Early Medieval East Asian Timeline system are to make adding and managing content easier as well as creating a platform upon which a community of scholars as well as regular users can regulate itself while contributing valuable content. For this, the new system will keep track of newly submitted articles about historic events as well as edits to and comments about current ones. The fate of submissions will be tracked by the system and all participants will be kept informed at all times. User accounts and privileges will also be tracked by the new system. Instead of the previously employed manual ways of moving information to its destination within the timeline, the new system will make positioning articles possible through an easily understood web-based GUI. SSAD_IOC2_S10b_T09_V /18/12

9 2.1.1 System context Figure 1: System Context Diagram SSAD_IOC2_S10b_T09_V /18/12

10 Table 1: Actors Summary Actor Description Responsibilities Administrator Person who adds or removes moderators; Adds or removes moderators Actor with the highest privilege level in the system Moderator Person who accepts or rejects Reviews new contributions contributions and controls the structure and contents of the website Arranges the contents of the website Manages contributor accounts Contributor Person who contributes one or more articles to the website Fills out template forms in order to edit articles or leave comments Reader Person who is a general reader of the Reads the website New Timeline System Data backup system website; unprivileged The new system that our team will build Manages user accounts Manages content submissions Places content in the timeline A computer that accepts data from the Accepts data for backups system for backup; not part of the system Reports backup results that our team will build SSAD_IOC2_S10b_T09_V /18/12

11 2.1.2 Artifacts & Information Figure 2: Artifacts and Information Diagram SSAD_IOC2_S10b_T09_V /18/12

12 Table 2: Artifacts and Information Summary Artifact ATF-1: Timeline Item ATF-2: Historical Detail ATF-3: Source ATF-4: Journal Source ATF-5: Comment ATF-6: User ATF-7: Personal Name Purpose A structured description of facts Supplemental information about historical articles Information about a source of historic information A source that comes from a scientific journal A message regarding an article. It that aims at prompting a moderator to change the contents of the referenced article or take different action A person who is known to the system and fills out at least one role. The name of a user of the system or of the author of a source SSAD_IOC2_S10b_T09_V /18/12

13 2.1.3 Behavior Figure 3: Process Diagram SSAD_IOC2_S10b_T09_V /18/12

14 Account Management Request contributor account Table 3: Process Description - Request contributor account Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-1: Request contributor account Reader can request a contributor account CR-3: Administrator/Moderators/Contributors need to have accounts to prevent abuse None Reader is on Request Contributor Account page Account database is updated with reader's contributor account and reader is returned to Login page unless request was rejected by system Table 4: Typical Course of Action - Request contributor account 1 On the Request Contributor Account page, the reader fills out information in the New Contributor Account form ( and Password required; Name, Organization, Occupation optional) 2 Reader clicks "Submit" 3 System saves account information as an inactive account in the account database and sends confirmation with activation link to the address supplied by the reader. Reader is returned to login page 4 Reader clicks on the account activation URL in the confirmation 5 System activates new account in the account database and displays activation notice page saying that reader's new contributor account has been activated SSAD_IOC2_S10b_T09_V /18/12

15 Table 5: Alternate Course of Action - Request contributor account 1 On the Request Contributor Account page, reader clicks on "Back" button 2 Form is not submitted; login page is displayed Table 6: Alternate Course of Action - Request contributor account 1 On the Request Contributor Account page, reader clicks on "Regimes Timeline" or "Events Timeline" link 2 Form is not submitted; Regimes timeline page or events timeline page are displayed according to reader's choice Table 7: Exceptional Course of Action - Request contributor account 1 On the Request Contributor Account page, the reader leaves and/or password blank or fills out implausibly (e.g. in the address) 2 Reader clicks "Submit" 3 System shows alert box reminding reader to at least fill out and password 4 Reader clicks OK on alert box or closes alert box 5 System stays on New Contributor Account form page with information that reader had already entered intact SSAD_IOC2_S10b_T09_V /18/12

16 Table 8: Exceptional Course of Action - Request contributor account 1 On the Request Contributor Account page, reader fills out at least and password 2 Reader clicks "Submit" 3 System determines that reader has submitted an address that already has an account associated with it 4 System displays red text on the Request Contributor Account page near the submit button with message that an account with the submitted address already exists. SSAD_IOC2_S10b_T09_V /18/12

17 Manage contributor accounts Table 9: Process Description - Manage contributor accounts Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-2: Manage contributor accounts Moderator can decide who is a contributor and edit account info as needed CR-3: Administrator/Moderators/Contributors need to have accounts to prevent abuse None Moderator is on Manage Contributor Accounts page Contributor information/status has been modified or the account deleted in the database unless the moderator left it unchanged Table 10: Typical Course of Action - Manage contributor accounts 1 On Manage Contributor Accounts page, moderator clicks on "Modify" next to an account 2 System displays account info in Edit Account Information form and gives control to "Edit Account Information" use case Table 11: Typical Course of Action - Manage contributor accounts 1 On Manage Contributor Accounts page, moderator clicks on "Delete" next to an account 2 System displays yes/no dialog box asking whether moderator really wants to delete this account 3 On yes/no dialog box, moderator clicks yes button 4 Account is deleted from account database; System displays Manage Contributor Accounts page SSAD_IOC2_S10b_T09_V /18/12

18 Table 12: Typical Course of Action - Manage contributor accounts 1 On Manage Contributor Accounts page, moderator clicks on "Delete" next to an account 2 System displays yes/no dialog box asking whether moderator really wants to delete this account 3 On yes/no dialog box, moderator clicks no button 4 Account is not deleted from account database; System displays Manage Contributor Accounts page Table 13: Alternate Course of Action - Manage contributor accounts 1 On Manage Contributor Accounts page, moderator clicks on "Log off" 2 Moderator is logged out of the system and system displays home page SSAD_IOC2_S10b_T09_V /18/12

19 Manage moderator accounts Table 14: Process Description - Manage moderator accounts Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-3: Manage moderator accounts Administrator can decide who is a moderator and edit account info as needed CR-1: The client (administrator) should have the ability to add moderator/contributor accounts CR-2: The client (administrator) should have the ability to delete moderator/contributor accounts None Administrator has opened Manage Moderator Accounts page Moderator information/status has is modified in the database unless the administrator left it unchanged Table 15: Typical Course of Action - Manage moderator accounts 1 On Manage Moderator Accounts page, administrator clicks on "Add account" 2 System displays empty Edit Account Information form and gives control to "Edit Account Information" use case Table 16: Typical Course of Action - Manage moderator accounts 1 On Manage Moderator Accounts page, administrator clicks on "Delete" next to an account 2 System displays yes/no dialog box asking whether moderator really wants to delete this account. 3 On the dialog box, administrator clicks on Yes 4 Account is deleted from account database; Manage Moderator Accounts page is displayed SSAD_IOC2_S10b_T09_V /18/12

20 Table 17: Alternate Course of Action - Manage moderator accounts 1 On Manage Moderator Accounts page, Administrator clicks on "Delete" next to an account 2 System displays yes/no dialog box asking whether administrator really wants to delete this account. 3 On the dialog box, administrator clicks on No 4 Account is not deleted from account database; Manage Moderator Accounts page is displayed SSAD_IOC2_S10b_T09_V /18/12

21 Login Table 18: Process Description - Login Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-4: Login Authenticate a privileged user CR-3: Administrator/Moderators/Contributors need to have accounts to prevent abuse. We need to make sure that the correct privileges for each user are set Contributor is not logged on to the system and on Login page Contributor is signed on to the system with his/her privileges (contributor, moderator or administrator) or login is rejected Table 19: Typical Course of Action - Login 1 On Login page, Contributor enters username/password correctly and clicks Submit 2 On Login page, contributor clicks "Submit" 3 Contributor is logged into the system and role is changed accordingly Table 20: Alternate Course of Action - Login 1 On Login page, contributor clicks on "Back" 2 User is not logged in and system displays page that was displayed before the login page was displayed SSAD_IOC2_S10b_T09_V /18/12

22 Table 21: Alternate Course of Action - Login 1 On Login page, contributor clicks on "Reset" 2 All values in form are erased in the form. Table 22: Exceptional Course of Action - Login 1 On Login page, contributor enters username/password 2 Contributor clicks "Submit" 3 System validates username/password combination and concludes it is incorrect 4 System displays red text on Login page saying that login was incorrect Logout Table 23: Process Description - Logout Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-5: Logout Remove privileges and continue session as unprivileged user CR-3: Administrator/Moderators/Contributors need to have accounts to prevent abuse None User is logged onto the system and system is displaying a page that needs privileges to be accessed User is logged off the system and continues session without privileges SSAD_IOC2_S10b_T09_V /18/12

23 Table 24: Typical Course of Action - Logout 1 On a page that needs privileges to be accessed, user clicks "Log off" link 2 System logs out the privileged account 3 System regime timeline page SSAD_IOC2_S10b_T09_V /18/12

24 Edit Account Information Table 25: Process Description - Edit Account Information Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-6: Edit Account Information Change account information CR-3: Administrators/Moderators/Contributors need to have accounts to prevent abuse None Moderator or administrator is on Edit Account Information page Account information is modified in the user information database unless it was left unchanged Table 26: Typical Course of Action - Edit Account Information 1 On Edit Account Information page, contributor, moderator or administrator edits account information in form field 2 On Edit Account Information page, contributor, moderator or administrator clicks "Submit" 3 Updated account information is committed to user database and control is returned to "Manage Contributor Account" use case if user is a moderator or "Manage Moderator Account" use case if user is an administrator SSAD_IOC2_S10b_T09_V /18/12

25 Table 27: Alternate Course of Action - Edit Account Information 1 On Edit Account Information page, contributor, moderator or administrator clicks "Return" 2 Control is handed back to returned to "Manage Contributor Account" use case if user is a moderator or "Manage Moderator Account" use case if user is an administrator Table 28: Exceptional Course of Action - Edit Account Information 1 On Edit Account Information page, contributor, moderator or administrator leaves a mandatory field blank or fills it out obviously wrong (e.g. address with ) and clicks Submit 2 On Edit Account Information page, contributor, moderator or administrator clicks "Submit" 3 System displays alert box saying which mandatory fields were left blank or filled out obviously wrong 4 On alert box, contributor, moderator or administrator clicks on OK or closes alert box 5 System displays Edit Account Information page SSAD_IOC2_S10b_T09_V /18/12

26 Submissions management List Submissions / Recent Changes Table 29: Process Description - List Submissions / Recent Changes Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-7: List submissions / recent changes Check new submissions list CR-6: Moderators should be able to authorize submissions online Make sure the moderator is shown all submissions and changes that need attention One or more submissions are stored in the new submissions queue and moderator is on List Submissions / Recent Changes page Moderator has seen overview and possibly processed one or more submissions Table 30: Typical Course of Action - List Submissions / Recent Changes 1 On Submissions Overview page, moderator clicks on the title of a submission 2 Selected submission is shown on Individual Submission Review page and control is given to " Individual Submission Review " use case SSAD_IOC2_S10b_T09_V /18/12

27 Individual submission review Table 31: Process Description - Individual submission review Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-8: Individual submission review Take action on a new submission CR-6: Moderators should be able to authorize submissions online CR-7: The system shall send an acknowledgment when a submission is received and another acknowledgment when the submission is accepted/rejected None A new submission is available for review by a moderator and is displayed on the List Submissions / Recent Changes page Moderator has reviewed the submission and taken action on it (accepted, rejected or edited it), the timeline is updated and the contributor who contributed the submission informed accordingly unless moderator has postponed action on the submission; An accepted submission is saved in the article database so that its individual parts can be retrieved within and outside of the system SSAD_IOC2_S10b_T09_V /18/12

28 Table 32: Typical Course of Action - Individual submission review 1 On List Submissions / Recent Changes page, moderator clicks on a listed submission 2 System displays Individual Submission Review page for the chosen submission 3 On Individual Submission Review page, moderator fills out the individual submission review form 4 Moderator clicks "Accept" button 5 Submission is inserted into the timeline in the location requested by contributor 6 System notifies contributor by that submission has been accepted Table 33: Alternate Course of Action - Individual submission review 1 On List Submissions / Recent Changes page, moderator clicks on a listed submission 2 System displays Individual Submission Review page for the chosen submission 1 On Individual Submission Review page, moderator clicks "Edit" 2 Article editor is displayed SSAD_IOC2_S10b_T09_V /18/12

29 Table 34: Alternate Course of Action - Individual submission review 1 On List Submissions / Recent Changes page, moderator clicks on a listed submission 2 System displays Individual Submission Review page for the chosen submission 3 On Individual Submission Review page, moderator fills out the individual submission review form 4 Moderator clicks "Reject" button 5 Submission is deleted from the submissions queue and article database 6 Contributor is notified by SSAD_IOC2_S10b_T09_V /18/12

30 Comment on article Table 35: Process Description - Comment on article Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-9: Comment on article Create or improve contents of an article CR-4: Contributors can submit bibliographic data for inclusion in the timeline None Contributor is logged on to the system and on Comment on Article page Comment was submitted to moderator unless contributor canceled submission Table 36: Typical Course of Action - Comment on article 1 On Comment on Article page, contributor edits contents of comment 2 On Comment on Article page, contributor clicks Submit 3 Comment is added to database, awaiting approval by Moderator Table 37: Exceptional Course of Action - Comment on article 1 On Comment on Article page. contributor does not fill out Regarding and/or Comment field and then clicks Submit 2 System shows alert box reminding reader to at fill out the required fields that were left unfilled ("Regarding" and or "Comment") 3 On alert box, contributor clicks on OK or closes alert box 4 System displays Comment on Article page SSAD_IOC2_S10b_T09_V /18/12

31 Edit Article Table 38: Process Description - Edit Article Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-10: Edit article Create or improve contents of an article CR-4: Contributors can submit bibliographic data for inclusion in the timeline CR-5: Contributors should be able to preview their uploaded contribution None Contributor or moderator has clicked on Modify Description link on an article page Contents of the article are changed unless moderator left them unchanged Table 39: Typical Course of Action - Edit Article 1 On the Edit Article page in the text area of the Edit Article form, contributor edits contents of submission 2 On the Edit Article page, contributor or moderator clicks on Submit 3 System validates input as complete 4 Submission is saved in the database; If Contributor is a moderator or administrator, submission is placed in the timeline. Otherwise, submission is marked in the database as being placed in the new submissions queue and shown in the timeline only to the contributor. SSAD_IOC2_S10b_T09_V /18/12

32 Table 40: Exceptional Course of Action - Edit Article 1 On the Edit Article page in the text area of the Edit Article form, contributor edits contents of submission 2 On the Edit Article page, contributor or moderator clicks on Submit 3 System validates input as incomplete 4 System shows error dialog box telling contributor which fields still need to be filled out 5 Contributor clicks OK on error dialog box or closes it 6 System displays Edit Article page SSAD_IOC2_S10b_T09_V /18/12

33 Add Source Table 41: Process Description - Add Source Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-11: Add Source Add a new citation source to the system so a moderator can add it to the timeline CR-4: Contributors can submit bibliographic data for inclusion in the timeline None Contributor is on a regime or event description box and has clicked on "Add Source" A new source has been added to the moderator queue unless the submission was invalid or cancelled Table 42: Typical Course of Action - Add Source 1 Contributor edits form fields for new source on the "Add Source" form 2 Contributor clicks "Submit" 3 System validates input as being correct (at least Title and Author fields are filled out) 4 New source is marked in the database as being in the submissions queue SSAD_IOC2_S10b_T09_V /18/12

34 Table 43: Exceptional Course of Action - Add Source 1 Contributor edits form fields for new source on the "Add Source" form 2 Contributor clicks on "Submit" 3 System validates input as being incorrect (at least Title or Author field is missing) 4 System shows error dialog box saying which fields where left blank or filled out incorrectly 5 Reader clicks "OK" on error dialog box or closes error dialog box 6 System displays New citation form SSAD_IOC2_S10b_T09_V /18/12

35 Modify Source Table 44: Process Description - Modify Source Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-12: Modify Source Modify a citation source in the system so a moderator can change it in the timeline CR-4: Contributors can submit bibliographic data for inclusion in the timeline None Contributor has clicked on "Modify Source" on a regime or event description box A modified source has been added to the moderator queue unless the submission was invalid or cancelled Table 45: Typical Course of Action - Modify Source 1 On a regime or event description box, contributor clicks on "Modify Source" 2 System displays modify source form with form fields filled in with values of the source selected by the user 3 Contributor edits form fields for modified source correctly (fills out at least Title and Author fields) 4 Contributor clicks "Submit" 5 Modified source is submitted to moderator queue in the database SSAD_IOC2_S10b_T09_V /18/12

36 Table 46: Exceptional Course of Action - Modify Source 1 System displays modify source form with form fields filled in with values of the source selected by the user 2 Contributor edits form fields for modified source incorrectly (leaves Title and Author fields blank or fills them out implausibly (e.g. only one character)) 3 Contributor clicks on "Submit" 4 System shows error dialog box saying which fields where left blank or filled out incorrectly 5 Reader clicks "OK" on error dialog box or closes error dialog box 6 System displays New Citation form SSAD_IOC2_S10b_T09_V /18/12

37 Read Article Table 47: Process Description - Read Article Identifier Purpose Requirements Development Risks Pre-conditions Post-conditions UC-13: Read Article View an article and possibly request editing the viewed article, adding a new article or to write a comment regarding the article CR-4: Contributors can submit bibliographic data for inclusion in the timeline None Reader has Timeline website open in browser Reader has the same article open in browser and possibly submitted an edited version of this article or a new article or a comment Table 48: Typical Course of Action - Read Article 1 On regime or event description box, reader clicks on "Add Source" link 2 Control is handed over to "Login" use case. If reader has successfully logged onto the system, control is handed over to "Add Source" use case, where reader acts as contributor SSAD_IOC2_S10b_T09_V /18/12

38 Table 49: Alternate Course of Action - Read Article 1 On regime or event description box, reader clicks on "Modify Source" link 2 Control is handed over to "Login" use case. If user has successfully logged onto the system, control is handed over to "Modify Source" use case, where reader acts as contributor Table 50: Alternate Course of Action - Read Article 1 On regime or event description box, reader clicks on "Modify Description" link 2 Control is handed over to "Login" use case. If user has successfully logged onto the system, control is handed over to "Modify Description" use case, where reader acts as contributor SSAD_IOC2_S10b_T09_V /18/12

39 2.1.4 Modes of Operation No modes of operation are planned for the system. While different actors will have different privileges, there will not be a situation where the same controls will give different responses. 2.2 System Analysis Rationale We have analyzed the current system as well as the new system desired by the client and come up with three kinds of operational stakeholders: Site staff: This is comprised of the administrator and the moderators. They manage how content is added to and modified on the site. With the new system, this will be accomplished by only acting within the system and using only the operations provided by it as opposed to directly editing and manipulating files. The administrator as well as the moderators will connect to the site over the internet or the USC intranet using web browsers exclusively. No access through low-level tools (such as shells or sftp clients) will be required in order to use the new system. Users: The people who read the content on the site or contribute content to it, but do not make any ultimate decisions on its content or direction. To the system, they are categorized through their roles as readers and the contributors. Readers and contributors will connect to the site over the internet using web browsers exclusively. Maintainer: The person who is part of the library IT staff and who keeps the site and its data up and running from an IT perspective after the new system has been deployed. The maintainer has no stake in the content of the site (i.e. he can perform his role with the same level of quality whether or not he ever actually reads any article on the site that is managed by the system). The maintainer can connect to the site over the internet or over the USC intranet using web browsers but will also have direct access to the underlying software using low-level tools (e.g. shells, sftp). The maintainer will also have physical access to the site. While there will be no external site interfacing with the new system as part of its core functionality, the system will be sending backups of its persistent data to a data backup system on a regular basis.usc ITS has committed to doing daily incremental backups as well as weekly full backups of the data on the site. These will be managed outside the system. SSAD_IOC2_S10b_T09_V /18/12

40 3. Technology-Independent Model This document has no technology-independent model because the technological foundation for the representation of historical data in the current and future system, MIT SIMILE timeline, has already been chosen by the client and therefore the new system needs to be shaped around it. SSAD_IOC2_S10b_T09_V /18/12

41 4. Technology-Specific System Design 4.1 Design Overview The new system will build on the existing two tier client / web server architecture based system and transform it into a three tier architecture. It will add a servlet container and a database to the previous architecture while moving from a pure web server to a servlet container that is also used as a web server. MIT SIMILE Timeline will continue to be the focal point of the system. The entire GUI will be realized using HTML pages and their elements, particularly forms. JavaScript will be used wherever input can be validated without needing complex business logic, e.g. when submissions need to be checked for empty fields, missing format elements and other immediately obvious errors. The back end business logic for the account management and article submissions will be run using Java Servlets that access a MySQL database. These servlets will be compiled from JSPs or written directly in Java. SSAD_IOC2_S10b_T09_V /18/12

42 4.1.1 System Structure Figure 4: Hardware Component Class Diagram SSAD_IOC2_S10b_T09_V /18/12

43 Figure 5: Software Component Class Diagram SSAD_IOC2_S10b_T09_V /18/12

44 Figure 6: Deployment Diagram SSAD_IOC2_S10b_T09_V /18/12

45 Table 51: Hardware Component Description Hardware Component Networked Computer Application Server Workstation Description A computer that is connected to other networked computers through the internet. In our system, every computer will be networked in this manner. A networked computer which provides applications to workstations. In our system, this will be the server our software will be deployed on. A networked computer which is used to access services on the internet. In our system, this will be computers used by people at home or in an office to interact with the timeline application server. Table 52: Software Component Description Software Component User Interface Account Management Module Submission Handling Module Database Handling Module Migration Manager Module MIT SIMILE timeline Description The HTML pages and forms that users of the system interact with directly The part of the system that keeps track of user account information and status, authenticates users and informs other components (such as the Submissions Handling Module) about the privileges of a given user Keeps track of and processes submissions of content to the system Interacts directly with the MySQL database via SQL and provides data storage, retrieval and query functionality to the other modules as needed. All other modules are database-agnostic. One-time use converter that migrates the existing content from the old system into the MySQL database of our new system A collection of JavaScript objects and methods that serve to represent historical data graphically in a timeline SSAD_IOC2_S10b_T09_V /18/12

46 Table 53: Supporting Software Component Description Support Software Component MySQL Apache Tomcat Description A relational database management system A servlet container SSAD_IOC2_S10b_T09_V /18/12

47 4.1.2 Design Classes Interface Classes Figure 7: Design Class Diagram SSAD_IOC2_S10b_T09_V /18/12

48 Table 54: Design Class Description Class Type Description Timeline Main Page Boundary Main page of the timeline site Article Page Boundary Shows an individual article Edit Article Page Boundary Page with a form to edit or create an article Comment on Article Page Boundary Page with a form to comment on an article Add Source Page Boundary Page with a form to add a source Modify Source Page Boundary Page with a form to modify a source Request Contributor Account Page Boundary Page with a form to request a contributor account Manage Contributor Accounts Page Boundary Page with a list of contributor accounts and buttons to modify or delete these accounts Manage Moderator Accounts Page Boundary Page with a list of moderator accounts and buttons to modify or delete these accounts Login Page Boundary Page with a login form Logoff Page Boundary Page with a logoff confirmation form Edit Account Information Page Boundary Page with a form to edit account information List Submissions / Recent Boundary Shows a list of submissions and recent Changes Page Individual Submission Review Page Boundary changes Shows an individual submission for review SSAD_IOC2_S10b_T09_V /18/12

49 Figure 8: Login Class Diagram SSAD_IOC2_S10b_T09_V /18/12

50 4.1.3 Process Realization The Process Realization diagrams show sequences for the most risky use cases. These are the use cases that, if implemented wrong, would cause the whole system or major parts of it to fail or at least to not work as expected (as opposed to those use cases whose faulty implementation would be contained to themselves) Login This is one of the riskiest use cases because all use cases that have privileged actors rely on a correctly implemented login. Figure 9: Process Realization Diagram - Login SSAD_IOC2_S10b_T09_V /18/12

51 Read Article This shows the interaction of our system with MIT SIMILE timeline, which is what our capability of displaying articles to users rests on. Figure 10: Process Realization Diagram - Read Article List Submissions / Recent Changes This is one of the most risky use cases because the moderator will take the articles he/she needs to work on from this list. If it were to be implemented wrong, some necessary work may not get done by the moderator. SSAD_IOC2_S10b_T09_V /18/12

52 Figure 11: Process Realization Diagram - List Submissions / Recent Changes SSAD_IOC2_S10b_T09_V /18/12

53 4.2 Design Rationale Our client has requested us to extend the functionality of his existing timeline system and to make working with his new system more efficient and community-based while being able to access all functionality using a GUI. Our solution for this is to provide the existing and newly added functionality using Java Servlets on an Apache Tomcat server with a MySQL database backend while leaving MIT SIMILE timeline in place. The existing functionality (displaying the timeline) will be provided through Apache Tomcat based Java Servlets and MIT SIMILE while using MySQL to hold the data. For this, the existing data will be migrated into a relational MySQL database. The new functionality (account management, submissions management and GUI-based positioning of articles in the timeline) will be realized by software components that will run as Java Servlets on Tomcat. Below is our rationale as to what the NDI components are that we chose and did not chose to realize the new system and how they interact NDI components Chosen NDI components Software Component MIT SIMILE Timeline MySQL Description Software system that represents data graphically in a timeline Relational Database Purpose Represent data about historic events, people and regimes Store user account information and metadata pertaining to the content of the timeline Management System Apache Tomcat Servlet container Provide facility to run Java Servlets which will be programmed by the team (Submissions Manager, Account Manager, Database Manager) Internet Explorer, Firefox, Safari Web browser Web front end for users of the existing and new timeline systems SSAD_IOC2_S10b_T09_V /18/12

54 NDI components that were not chosen PHP Two NDI components that could have provided some functionality for the system (Submissions Manager, Account Manager), but were not chosen, are the PHP language and its corresponding Apache web server extension. In the first semester of this project, this choice was made for two reasons: 1. It was felt that while PHP can provide the required functionality, using Apache Tomcat and Java Servlets would be a better fit if the system needs to scale upwards. 2. The team has more experience using Apache Tomcat and Java Servlets. This reason could have potentially become irrelevant if the project would have been transferred to another team or the team members who have more experience with Tomcat and Servlets than with PHP would have left the team before the start of development in the second semester. However, as it actually turned out, all the team members that were relevant to this decision are still with the team as of the second semester Apache Web Server The current system will be migrated to the Apache Tomcat server, which will serve both static and dynamic HTML pages. While in a high performance context it may make sense to run both the Apache web server and Apache Tomcat in parallel, it was felt here that the modest performance requirements of the timeline system do not require that kind of setup. This will still hold true for any reasonably expected evolution of the system during its lifetime Interfaces Since our new system will be an extension of an existing system, the new system will interface with the same systems as the existing system. These systems the internet connected workstations of web users and the networked workstations of the site staff and the maintainers. In addition to that, there will be a need to interface with a data backup system and a database running on the same server as Apache Tomcat. The figure below shows the integration of the software components comprising the new system. These are split into three major groups: Client-side (Browsers and their underlying operating systems), Web servers and their business logic (Apache Tomcat with a Java SDK and underlying operating systems) and the database back-end. SSAD_IOC2_S10b_T09_V /18/12

55 While istudio 0.21 has been used to produce the figure shown here, we have not used it to determine mismatches and incompatibilities. The reason for this is that its reports showed a large amount of mismatches between components that are well-known to work with each other. Fixing these non-existent mismatches would have required a large amount of editing the XML descriptions of components, which would have added no value to our project. We also feel that figure shows only connections between components that are well-known to work with each other. These are as follows: Laterally (integration of different components within one physical system): Web browsers are known to work on Windows, Mac and other client platforms. Combinations of Apache Tomcat with Servlets and Java EE are known to work together on Windows Server MySQL is known to work on Windows Server Vertically (integration of different components between several physical systems): Web browsers such as Safari, Internet Explorer and Firefox are known to work with web servers or Java servlet containers using the HTTP protocol such as Apache Tomcat. Tomcat is known to work with MySQL using the JDBC connector that comes with Tomcat. SSAD_IOC2_S10b_T09_V /18/12

56 Figure 12: istudio diagram of the new system SSAD_IOC2_S10b_T09_V /18/12

57 4.2.2 Connectors Component 1 Component 2 Connector Web browser Apache Tomcat Built-in MIT SIMILE Timeline Apache Tomcat JavaScript source of MIT SIMILE Timeline is referenced in HTML pages Apache Tomcat MySQL JDBC Because all required connectors between components are either built into the components (Apache Tomcat, web browsers), URLs are being referenced (Apache Tomcat/SIMILE) or the connectors are part of the distribution of the NDI component (Apache Tomcat/MySQL), no connectors between the components will need to be programmed by our team. SSAD_IOC2_S10b_T09_V /18/12

58 5. Architectural Styles, Patterns and Frameworks Three-tier Architecture Table 55: Architectural Styles, Patterns, and Frameworks Name Description Benefits, Costs, and Limitations Three-tier architecture is an Benefits: architectural style and a design pattern Individual tiers can be modified that separates the presentation of data, independently from the rest of business logic and the data itself into the system without breaking it tiers that, in the case of our system, (less coupled than a monolithic reside on two different systems and are architecture) managed with three different applications: All data is presented within web browsers (Internet Explorer, Mozilla Firefox, Apple Safari) on networked machines that will in most cases be offsite. The business logic platform will be Apache Tomcat running on Windows Server The data will be managed using a MySQL database running on Windows Server 2008 on the same virtual machine as Apache Tomcat (this is based on the setup of the physical system, MySQL could just as well run on a different machine without causing any detriment to the functionality of our system) Cost: Enforces separation of data, business logic and presentation on the developers, thereby making them create code that is more easily maintained because its functionality is more easily understood due to its impact being more localized within the system. There is no specific cost required in order to use threetier architecture. Limitations: Potential limited speed losses when data which is transferred between the browser and the database and vice versa has to pass through the separate business layer and has to be replicated in the database and the servlet container SSAD_IOC2_S10b_T09_V /18/12