1	Literate Specification: A Framework for Documenting and Implementing Business Rules in the Database Alfredo Torrez Project ILACO II, Bolivia ..., make known to them the design of the temple --its arrangement, its exists and entrances-- its whole design and all its regulations and laws. Write these down before them so they may be faithful to its design and follow all its regulations. Ezekiel 43:11
2	The Literate Specification Language This language: Is a simplified version of a literate language. It lets organize the business’ knowledge in a textual manner, with subtle syntax impositions allows to obtain units of specification code that are between the IMPLEMENTATION CODE and the BR DECLARATION Is oriented to specify Business Rules (BR), the Transformations and the Life Cycle of an Entity
3	The Business Rules A Business Rule contains three kinds of knowledge: Actions, that refer to the knowledge of ‘How’ to do something Decisions, that relate to the knowledge of ‘When’ the actions will be applied Entities, that identify to ‘Whom’ the actions and decisions will affect and will be applied to According to the hierarchy of execution and application, the BR have been classified in high, top, middle and low level rules
4	The Life Cycle of an Entity It is a model that defines the entity’s behaviour, since it is created until it is removed definitively. This model is described as a states machine, extended to represent different types of Business Rules States are rules that define the moments in which an entity will be transformed in other one Transformations are rules that define the most important events that might occur over an entity Transitions are rules that prevent improperly usage of the transformations over an entity.
5	Language Features It uses five tags for remarking It has three sentences It intermingles text among the tags This language, with the tags, is trying to encapsulate and hide the specific knowledge, nevertheless, with the text, it is trying to clarify the pinpoints made with the tags
6	Language Tags Directive and Guide tags ( ) Directive tag is used to point out the decision criteria and condition rules. The & operator is used for joining decision criteria
7	Language Tags Rule Tag < > Rule Tag is taken into account to emphasize actions and determinations
8	Language Tags Pattern, End and Loop Tag { } Pattern tag is used to arrange other tags including itself within valid rule chunks
9	Combining Tags for building patterns Sequence
10	Combining Tags for building patterns Case
11	Language Sentences lifecycle sentence In relation to a table, it lets define: the records’ states; the table’s transformations; the transition constraints and the default rules
12	Language Sentences transformation sentence Lets program the top level rules to be applied over a table’s records
13	Language Sentences rule sentence Lets organize the knowledge (actions and decision structure) implied in a rule
14	Bank Account Entity’s Life Cycle Life Cycle Literate Specification lifecycle BANK_ACCOUNTS { (TYPE_OF_RULE) [STATES] { <OPENED, ‘The Account is empty and recently created’> <PREPARED, ‘The Account is prepared for entering in operation’> <OPERATING, ‘The Account is operating’> <SUSPENDED, ‘The Account is out of operation’> <CLOSED, ‘The Account is closed’> }
15	Bank Account Entity’s Life Cycle ... Continuing [TRANSFORMATIONS] { <OPEN, ‘Create a new account’, INSERT> <MODIFY, ‘Modify a new account’, UPDATE> <ELIMINATE, ‘Delete a new account definitively’, DELETE> <PREPARE, ‘Prepare for entering a new account ...’, UPDATE> <RESTORE, ‘Restore the account preparation’, UPDATE> <ENABLE, ‘Enable a prepared account for operating’, UPDATE> <DEPOSIT, ‘Propagate the deposits to an operating ...’, UPDATE> <WITHDRAW, ‘Propagate the withdrawals to an ...’, UPDATE> <SUSPEND, ‘Suspend an operating account’, UPDATE> <RESUME, ‘Resume a suspended account’, UPDATE> <CLOSE, ‘Close a suspended account’, UPDATE> }
16	Bank Account Entity’s Life Cycle ... Continuing [TRANSITIONS] { <START, OPEN, OPENED> <OPENED, MODIFY, OPENED> <OPENED, PREPARE, PREPARED> <PREPARED, UNPREPARED, OPENED> <PREPARED, RESTORE, OPERATING> <OPERATING, DEPOSIT, OPERATING> <OPERATING, WITHDRAW, OPERATING> <OPERATING, SUSPEND, SUSPENDED> <SUSPEND, RESUME, OPERATING> <SUSPEND, CLOSE, CLOSED> <OPENED, ELIMINATE, END> } [DEFAULT RULES] { <control the permissions and register audit information> } }
17	Bank Account Entity’s Life Cycle Transformation Literate Specification
18	Rule Literate Specification rule (the information of the owner of the account has been changed) { (the first name is changed) <return TRUE> (the last name is changed) <return TRUE> (the telephone number is changed) <return TRUE> <return FALSE>\ }
19	The Text inside of the Specification transformation WITHDRAW { When withdrawing a certain amount of money from an account, the following BEFORE ROW and AFTER STATEMENTS actions or controls must take place according to the (MOMENT & LEVEL): when it is [BEFORE ROW] then, the engine must: { <check the user’s permission over transformation>, <check the transformation’s permissions for changing the ...>, <validate the column’s values> and <deduct the quantity withdrawn from the account’s balance> }; finally, when it is [AFTER STATEMENT] then, the engine must { <save audit information at record level> }. }
20	Language’s Abstract Machine This machine supports creation, modification and elimination events. Each one of them transform an entity from current state to another state individually or collectively. This machine works as a control and application mechanism of BR. It is in charge of constraining the inappropriate application of the transformations through a state control mechanism.
21	Language’s Abstract Machine
22	Documentation Framework The documentation is based on the rule, transformation and lifecycle sentence of this language The language’s compiler lets obtain and store enough information for generating any kind of documentation
23	Framework’s Table Scheme The information obtained from lifecycle, transformation and rule sentence is stored in the next table scheme
24	Implementation Framework It is based on the Language’s Abstract Machine which is implemented as: Twelve triggers by which the insert, update and delete events are implemented A control package in which the state control mechanism are defined A PL/SQL table by which the machine’s tapes defined in the control package is implemented
25	BR Implementation The BR are implemented as: BR packages, in which the top, middle and low level rules procedures/functions are defined Database tables, where the transitions constraints are stored for enacting in runtime Procedures, by which each transformation declared in the control package are implemented
26	Experiences and Conclusions In our case the development methodology has been changed the applications have to be thought in terms of BR the analysts and business rule experts are and will be more involved in the development and maintenance of BR specifications The language lets implement many types of BR Some problems gain importance the generation of the specific PL/SQL code for low level BR the dynamic on/off switching of the BR the BR that affect recurrently a table
27	Thanks for your attention! Questions & Answers Contact Information e-mail: Home : atorrezgaray@hotmail.com Work : atorrez@ilaco.gov.bo phone: Office : (591-2) 200822 Cell : (591-15) 57322