We all make mistakes. Making mistakes is an opportunity to learn. But as a first step you have to recognize the mistakes you made. If you don't, those mistakes might evolve into a practice. A bad practice. But you can also learn from someone else's mistakes. That's why I crowdsourced "Bad Practices" that people have encountered in the wild. And I was suprised by the numerous examples people came up with. So this session will cover real world examples of practices that are labeled as "bad". Of course we will discuss why these practices are bad and what would be the better solution.

1. Copyright © 2019 APEX Consulting
APEX Bad Practices

3. <bragging>

5. </bragging>

6. 3 Membership Tiers
• Oracle ACE Director
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500+ Technical
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Connect:
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10. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

11. Get organised

12. Naming stuff

17. Need a Page Item Value on other pages?
Use an Application Item
Use P0_EMPNO
Use P1_EMPNO

19. $(“#P1_EMPNO”)apex.item(“P1_EMPNO”)

21. Divide and conquer

22. A few Applications
with a lot of Pages

23. A lot of Applications
with a few Pages

24. MASTER
SEED
subscription
APP 1
APP 2
APP 3
copy
subscription subscription subscription

25. ✅
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✅
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26. Page 0

27. Unsubscribe

28. NEVER Unsubscribe

30. Don’t put your files
in the APEX directories

33. /usr/local/tomcat/webapps/i

34. /usr/local/tomcat/webapps/
mycode
/mycode/js/myJsFile.js

35. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

36. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

37. Dude, where’s my code?

39. Process
Region / Item Source
Condition
Read Only Condition
Item Default
Dynamic Action
Validation
Where CAN you put your PL/SQL?

40. Where SHOULD you put your PL/SQL?
Reusable
Testable
Compiled
Dependencies

41. Some more remarks
regarding PL/SQL

43. select *
from my_big_table
where field = v('P2_EMPNO')

44. select *
from my_big_table
where field =
( select v('P2_EMPNO')
from dual )

45. with param as
( select v('P2_EMPNO') empno
from dual )
select *
from my_big_table
, param
where field = param.empno

46. with param as
( select /*+ MATERIALIZE */
v('P2_EMPNO') empno
from dual )
select *
from my_big_table
, param
where field = param.empno

49. FORMAT MASK

51. render / submit / ajax

55. Beware of
undocumented
features

57. APEX 5
APEX 18
:APXWS_SEARCH_STRING_1
:APXWS_EXPR_1
:apex$f1
https://roelhartman.blogspot.com/2016/07/prevent-general-row-based-search-in.html

58. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

59. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

60. And what about
JavaScript …

62. Page “JavaScript section”
Page header / footer
Region header / footer
Item Pre / Post Text
URL target
Dynamic Action When / Condition
DA Action : Execute JavaScript Code
Where CAN you put your JavaScript?

63. Where SHOULD you put your JavaScript?
In a file (on your network / static app file)
(reference in the User Interface Details)
In a Plugin (JavaScript file)
Roels Rule : No JavaScript anywhere else

64. The code is more what you'd call "guidelines" than actual rules

65. How should you code your JavaScript?
$(“#P1_EMPNO”)
or
apex.item(“P1_EMPNO”)

68. How should you code your JavaScript?
$v(“#P1_EMPNO”)
or
apex.item(“P1_EMPNO”).getValue()

69. How should you code your JavaScript?
$v(“P1_EMPNO”)
or
apex.item(“P1_EMPNO”).getValue()

72. Know your APEX JavaScript API’s
https://docs.oracle.com/en/database/oracle/application-express/19.1/aexjs/index.html

73. Beware of undocumented features

74. gReport

75. htmldb_Get

76. A lot of stuff in the Interactive Grid

77. Watch your plugins …

78. Beware of undocumented features

79. Beware of DOCUMENTED features

81. function render
( p_dynamic_action in apex_plugin.t_dynamic_action
, p_plugin in apex_plugin.t_plugin
)
return apex_plugin.t_dynamic_action_render_result
is
l_result apex_plugin.t_dynamic_action_render_result;
begin
l_result.javascript_function :=
'function(){
openModal( this.affectedElements[0].id );
}';
return l_result;
end;

83. function render
( p_dynamic_action in apex_plugin.t_dynamic_action
, p_plugin in apex_plugin.t_plugin
)
return apex_plugin.t_dynamic_action_render_result
is
l_result apex_plugin.t_dynamic_action_render_result;
begin
l_result.javascript_function :=
'function(){
openModal( this.affectedElements[0].id );
}';
return l_result;
end;

84. function render
( p_dynamic_action in apex_plugin.t_dynamic_action
, p_plugin in apex_plugin.t_plugin
)
return apex_plugin.t_dynamic_action_render_result
is
l_result apex_plugin.t_dynamic_action_render_result;
begin
l_result.javascript_function :=
'function({
apex.theme.openRegion( this.affectedElements[0].id );
}';
return l_result;
end;

86. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

87. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

88. Miscellaneous

89. Dynamic Actions are cool

91. Page Process / Computation

93. Region refresh
Page refresh
Row refresh

94. function render
( p_dynamic_action in apex_plugin.t_dynamic_action
, p_plugin in apex_plugin.t_plugin
)
return apex_plugin.t_dynamic_action_render_result
is
l_result apex_plugin.t_dynamic_action_render_result;
begin
l_result.javascript_function :=
'function(){
var myGrid = apex.region( this.affectedElements[0].id )
.widget().interactiveGrid("getViews").grid;
myGrid.model.fetchRecords( myGrid.getSelectedRecords() );
}';
return l_result;
end;

95. Get organised
Dude, where’s my
code?
And what about
JavaScript …
Miscellaneous

97. Copyright © 2019 APEX Consulting
Q& A@roelh
roel@apexconsulting.nl
http://www.apexconsulting.nl

98. @roelh
roel@apexconsulting.nl
http://www.apexconsulting.nl
Copyright © 2019 APEX Consulting