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The Power of the Oracle APEX Repository Patrick Wolf, Sphinx IT Consulting DOAG SIG – APEX for Advanced, 31-May-2007.

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Presentation on theme: "The Power of the Oracle APEX Repository Patrick Wolf, Sphinx IT Consulting DOAG SIG – APEX for Advanced, 31-May-2007."— Presentation transcript:

1 The Power of the Oracle APEX Repository Patrick Wolf, Sphinx IT Consulting DOAG SIG – APEX for Advanced, 31-May-2007

2 About Sphinx IT Consulting
Founded 1993 Creates mission-critical individual software Consulting for Databases & Java Middleware Specialized in Oracle More information at About Patrick Wolf 13 years of Oracle experience with SQL, PL/SQL and Oracle Forms Solution Architect at Sphinx IT Consulting Run an APEX Blog – Author of the ApexLib Frameworks – Author of the Oracle APEX Builder Plugins Contact mail is

3 Agenda The Oracle APEX Repository Part 1 - The APEX Dictionary Views
Simple queries Automatic documentation creation Monitoring APEX Applikations Create generic code using the repository Part 2 – Directly manipulating the APEX Repository Do mass updates in the Repository Create new Page Items, ... Q&A

4 The Oracle APEX Repository
Oracle APEX stores all meta-data of an application in a repostiory in the database Schema FLOWS_xxx (eg.: FLOWS_030000) Table prefixed with WWV_FLOW_* This tables are not public. Starting with version 2.2 there is a view access layer. Prefix of the views is APEX_* Since 3.0 there is an user interface for simple queries. Can be found at Utilities/APEX Dictionary

5 The APEX Dictionary Views
Returns a „readable“ form of the internal APEX Repository tables Hide the generic/old data model Lookups for Foreign-Keys Translate interne Enumerations into English Contains statistic counters – eg. Number of child elements Checks access privileges (you only see your applications) Connected as schema user: All applications of the workspaces where the schema is assigned to. Connected as SYS, SYSTEM, FLOWS_xxx: All applications Other users: nothing The Views are public and can therefore be used in APEX applications or in external scripts.

6 The APEX Dictionary Views

7 The APEX Dictionary Views
Select Tree view

8 The APEX Dictionary Views
Hierarchical representation

9 The APEX Dictionary Views
Documentation of each column

10 The APEX Dictionary Views

11 The APEX Dictionary Views
Don’t forget the quote! To execute press „Go“ button at the beginning of the page

12 The APEX Dictionary Views

13 The APEX Dictionary Views
What are usage examples for the views? A few examples Quality checks a coding styleguides, … Dynamic generation of Site-Maps Automatic documentation of the application Automatic monitoring of the application Some nice page view charts For the creating of generic code And so on...


15 Quality check 2 Are all labels left aligned? SELECT APPLICATION_NAME

16 Quality check 3 Has a help text been entered for all Page Items where the „xxx Label with Help“ Template has been used? SELECT APPLICATION_NAME , PAGE_ID , ITEM_NAME , DISPLAY_AS FROM APEX_APPLICATION_PAGE_ITEMS WHERE ITEM_LABEL_TEMPLATE LIKE '%Label with Help' AND DISPLAY_AS <> 'Hidden' AND ITEM_HELP_TEXT IS NULL ORDER BY APPLICATION_NAME ;

17 Dynamic Site-Maps Create a automatically generated Site-Map for your application. Tag relevant pages with $SITEMAP$ in the page comment. SELECT PAGE_ID , PAGE_TITLE , PAGE_GROUP FROM APEX_APPLICATION_PAGES WHERE APPLICATION_ID = :APP_ID AND INSTR(PAGE_COMMENT, '$SITEMAP$') > 0 ORDER BY PAGE_TITLE ; Create SQL Report with above SQL statement. For column „PAGE_TITLE“, change Link Text to #PAGE_TITLE# and Page to #PAGE_ID# Set column „PAGE_ID“ to „Hidden“. Page Groups could be used to get a hierarchical representation in a tree view…

18 Automatic Documentation
Wouldn’t it be nice to have a diagram of the Page Flow of an application? Which page calls which page… Like JDeveloper, where there is a Page Flow editor for JSF applications, but which has be manually mantained… Not like other development environments where the necessary data is stored somewhere in XML files or in Java/… code, we have all the necessary data accessible with simple SQL queries! With the help of Graphviz an open source tool, the graphical diagram generation is quite easy.

19 Page Flow Generator Analyses the meta-data of an application, like Pages, Branches, Buttons, Links- in Report Columns, HTML Regions and SQL Statements. Creates a dependency model in the memory and creates for each Page Group (to keep them small) it’s own diagram. The complicated part was the Graphviz syntax. The Page Flow Generator is part of the ApexLib Frameworks.


21 Monitoring APEX Applications 1
Wouldn’t it be cool if the administrator automatically gets notified if an error occurs in the application? APEX provides the view APEX_WORKSPACE_ACTIVITY_LOG and the column ERROR_MESSAGE for such a purpose. A DBMS_JOB can be used to check it periodically. See blog entry And with you can set it up to send a SMS.

22 Monitoring APEX Applications 2
How to detect hackers trying to break into your application? The view APEX_WORKSPACE_ACCESS_LOG logs each login attempt with the following data Timestamp Usernamen IP address Result – Successful/Failed

23 Monitoring APEX Applications 3
How can you detect if the response time of you application decreases? The view APEX_WORKSPACE_ACTIVITY_LOG logs each page access and the column ELAPSED_TIME tells you how long APEX needed to generate the page. Combined with historical data and the number of users currently accessing the system you can estimate a trend of your response time. The view can also be used to analyze the navigation behavior of your users. Also see column THINK_TIME for the time the user waited till opened another page. Or create a query which returns the pages which are never called. And so on…

24 Create Generic Code 1 Ever had the problem that you had a page where the Page Items are very similar and number VALUE1, VALUE2, … and where you had to create the same validation for all of them? Boring job, isn’t it? There is also a way to do it with less effort! BEGIN FOR rITEM IN ( SELECT ITEM_NAME FROM APEX_APPLICATION_PAGE_ITEMS WHERE APPLICATION_ID = :APP_ID AND PAGE_ID = :PAGE_ID AND ITEM_NAME LIKE 'P'||:PAGE_ID||'_VALUE%' ) LOOP IF V(rITEM.ITEM_NAME) IS NOT NULL THEN APEX_Util.set_session_state ( p_name => rITEM.ITEM_NAME , p_value => 1 ); END IF; END;

25 Create Generic Code 2 Ever needed a cascading/hierarchical LOV?
Have you implemented Carl Backstom’s ( AJAX example for each LOV? Isn’t all required information available in the meta-data of the Page Item? The WHERE clause of the LOV contains all dependencies! Why don’t we use it and stop duplicating code and information about the dependencies? That’s what the Open Source ApexLib Framework ( does! Short demonstration of the framework.

26 APEX Dictionary Views - Conclusio
Are a powerful tool which you can use to enhance your application of your development process. There a lot of possible scenarios where you can use them, you just have to come up with some good ideas. Use the APEX Dictionary View Browser to get used to them! Available since Oracle APEX Version 2.2.

27 Manipulating the APEX Repository
Ever had the requirement to make a bulk update in your application? For example to change the Label Template to “without Help” for all Page Items. Or create with your own code Page Items, … Your own wizard. Oracle APEX doesn’t offer an official tool to fulfill above requirements. But if already all the meta-data of the application are in the database… But the result of doing a direct update on the repository tables can really be surprising. The application isn’t accessible anymore in the builder! So how do it the right way?

28 Manipulating the APEX Repository
BACKUP, BACKUP, BACKUP!!! Make a backup/export of the FLOWS_XXX schema before you do any manipulation of the repository tables! At least do an export of your application! Use the following tips at your own risk !

29 Manipulating the APEX Repository
The manipulation is down connected as FLOWS_xxx (eg. FLOWS_030000). The tables are prefixed with WWV_FLOW* The best way to identify the tables and columns is to have a look at the APEX Dictionary Views. Create a reference record. Eg. With the new Label Template Set APEX context with WWV_Flow_API.set_security_group_id What is the Security Group ID? Is equal to the Workspace ID and can be get with Apex_Util.get_security_group_id(`Workspacename`)

30 Manipulating the APEX Repository
Example to initialize the APEX context. DECLARE vSecurityGroupId NUMBER; BEGIN vSecurityGroupId := Apex_Util.find_security_group_id ( p_workspace => 'SPHINX_SXSD' ); IF vSecurityGroupId = 0 THEN RAISE_APPLICATION_ERROR ( , 'Workspace not found! Do not issue updates' END IF; -- WWV_Flow_Api.set_security_group_id(vSecurityGroupId); WWV_Flow.g_user := 'PWOLF'; END;

31 Manipulating the APEX Repository
Example which sets the Label Template from „Optional Label with Help“ to „Optional Label“ on all Page Items on page 4. UPDATE WWV_FLOW_STEP_ITEMS SET ITEM_FIELD_TEMPLATE = E18 WHERE FLOW_ID = 106 AND FLOW_STEP_ID = 4 AND ITEM_FIELD_TEMPLATE = E18 ; FLOW_STEP_ID equal to Page Id FLOW_ID equals to Application Id

32 Manipulating the APEX Repository
What can I do if my application isn’t accessible after an update anymore? Check the SECURITY_GROUP_ID in WWV_FLOWS. If it’s 0, initialize the APEX context and set the SECURITY_GROUP_ID in WWV_FLOWS again. UPDATE WWV_FLOWS SET SECURITY_GROUP_ID = NULL WHERE FLOW_ID = 106 ; NULL is used by intention!

33 Manipulating the APEX Repository
How can we create new Page Items, …? APEX provides the public(!) but undocumented package WWV_Flow_Api Can be called from a package in the application schema or from FLOWS_XXX. There are a lot of examples, just view the export file of an application. WWV_Flow_Api.g_id_offset is used during import to get unique IDs -> not required in our case. The next free ID is returned by WWV_Flow_Id.next_val.

34 Manipulating the APEX Repository
The following session initialization steps are required if you are executing the code outside of an APEX session. For example when you are connected to FLOWS_XXX. Initialize APEX context as done for an update + execute the following code. BEGIN SELECT VALUE INTO WWV_Flow_Api.g_nls_numeric_chars FROM NLS_SESSION_PARAMETERS WHERE PARAMETER = 'NLS_NUMERIC_CHARACTERS' ; EXECUTE IMMEDIATE 'ALTER SESSION SET NLS_NUMERIC_CHARACTERS=''.,'''; -- WWV_FLOW.g_browser_language := 'en'; WWV_Flow_Api.g_id_offset := 0; END;

35 Manipulating the APEX Repository
Just create a new Page Item with the following example code. DECLARE vPageItemId NUMBER; BEGIN WWV_Flow_Api.set_version ( WWV_Flow_Api.g_compatable_from_version ); WWV_Flow.g_flow_id := 100; -- Application Id -- vPageItemId := WWV_Flow_Id.next_val; WWV_Flow_Api.create_page_item ( p_id => vPageItemId , p_flow_id => WWV_Flow.g_flow_id , p_flow_step_id => 4 , p_name => 'P4_TESTIT' ... END;

36 Manipulating the APEX Repository - Conclusio
BACKUP, BACKUP, BACKUP!!! For updates, do a direct update on the tables. Always create a Reference record. Do inserts with the WWV_Flow_Api package. Application export file has good example.

37 Any questions?

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