The affect of failed validation on the page rendering phase

Question

This is divided in two parts. In the first one I describe the behavior and in the second I show work around and make a suggestion.
The need that started this was that the value an item needed to be recalculated each time de page was shown. This page could be called from buttons and from branches on other pages. So the logical place to put this calculation is in Computation of the Page Rendering phase. But, when a validation failed the value wasn't shown on the browser and I later discovered it was not calculated at all. I tried moving the calculation in a Process of the Page Rendering phase, but to that didn't worked either. So I needed to have a beter understanding of happens when a validation fails, ence this test.
The test was done on version 3.1.2 of APEX.
For this test, here is what I programmed (if no values is specified, than the property has the default value):
1. I created a blank page
-- In the Page Rendering part --
2. I created a region with the following properties
Identification
- Title: Alpha
- Type: PL/SQL (Anonymous block)
Source
- Region Source: wwv_flow.debug('> RENDER REGION Alpha SOURCE');
Conditional Display
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER REGION Alpha CONDITION'); RETURN TRUE;
Caching
- Caching: Cahed
- Cache Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER REGION Alpha CACHE CONDITION'); RETURN TRUE;
3. I created an item with the following properties
Name
- Name: P1_X
- Display As: Textfield
Displayed
- Region: Alpha
Source
- Source Used: Always, replacing any existing value in session state
- Source Type: PL/SQL Function body
- Source value or expression: wwv_flow.debug('> RENDER ITEM P1_X SOURCE'); RETURN NULL;
- Post Calculation Computation: :P1_X || ' POST-CALCUL'
Default
- Default value: wwv_flow.debug('> RENDER ITEM P1_X DEFAULT'); RETURN 'RENDER ITEM P1_X DEFAULT';
- Default Value Type: PL/SQL Function body
Conditions
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER ITEM P1_X CONDITION'); wwv_flow.debug('> P1_X="'||:P1_X||'"'); RETURN TRUE;
Read Only
- Read Only Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER ITEM P1_X READ_ONLY CONDITION'); RETURN FALSE;
4. I created a second item with the following properties
- Name: P1_Y
- Display As: Textfield
Displayed
- Region: Alpha
Source
- Source Used: Only when current value in session state is null
- Source Type: PL/SQL Function body
- Source value or expression: wwv_flow.debug('> RENDER ITEM P1_Y SOURCE'); RETURN NULL;
- Post Calculation Computation: :P1_Y || ' POST-CALCUL'
Default
- Default value: wwv_flow.debug('> RENDER ITEM P1_Y DEFAULT'); RETURN 'RENDER ITEM P1_Y DEFAULT';
- Default Value Type: PL/SQL Function body
Conditions
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER ITEM P1_Y CONDITION'); wwv_flow.debug('> P1_Y="'||:P1_Y||'"'); RETURN TRUE;
Read Only
- Read Only Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER ITEM P1_Y READ-ONLY CONDITION'); RETURN FALSE;
5. I created a button with the following properties
Name
- Button Name: GO
- Text Label/Alt: Go
Displayed
- Display in Region: Alpha
- Button Position: Top of Region
Conditions
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER BUTTON Go CONDITION'); RETURN TRUE;
6. I created a second button with the following properties
Name
- Button Name: GOERRNULL
- Text Label/Alt: Go invalid
Displayed
- Display in Region: Alpha
- Button Position: Top of Region
Conditions
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER BUTTON Go invalid CONDITION'); RETURN TRUE;
7. I created a thrid button with the following properties
Name
- Button Name: RESET
- Text Label/Alt: Reset cache
Displayed
- Display in Region: Alpha
- Button Position: Top of Region
Conditions
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER BUTTON Reset CONDITION'); RETURN TRUE;
Optional URL Redirect
- Target is a: Page in this Appplication
- Page: 1
- resetpagination for this page: checked
- Request: RESET
- Clear Cache: 1
8. I created a computation with the following properties
Item Name
- Item Name: P1_Y
- Type: PL/SQL Function body
Computation Point
- Computation Point:Before Header
Source
- Computation: wwv_flow.debug('> RENDER CALCUL P1_Y SOURCE'); RETURN 'RENDER CALCUL P1_Y SOURCE';
Conditional Computations
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER CALCUL P1_Y CONDITION'); RETURN TRUE;
9. I created a process
Name
- Name: Beta
- Type: PL/SQL anonymous block
Process Point
- Process Point: On Load - Before Header
- Run Process: Once Per Page Visit (Default)
Source
- Process: wwv_flow.debug('> RENDER PROC Beta SOURCE');
Conditional Processing
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> RENDER PROC Beta CONDITION'); RETURN TRUE;
-- In the Page Processing part --
10. I created a computation
Item Name
- Item Name: P1_Y
- Type: PL/SQL Function body
Computation Point
- Computation Point:After Submit
Source
- Computation: wwv_flow.debug('> PROC CALCUL P1_Y SOURCE'); RETURN 'PROC CALCUL P1_Y SOURCE';
Conditional Computations
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> PROC CALCUL P1_Y CONDITION'); RETURN TRUE;
11. I created a second computation
Item Name
- Item Name: P1_X
- Type: PL/SQL Function body
Computation Point
- Computation Point:After Submit
Source
- Computation: wwv_flow.debug('> PROC CALCUL P1_X SOURCE'); RETURN NULL;
Conditional Computations
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> PROC CALCUL P1_X CONDITION'); RETURN TRUE;
12. I created a validation
Validation
- Name: Delta
- Type: Function Returning Boolean
- Validation Expression 1: wwv_flow.debug('> PROC VALIDATION Delta SOURCE'); RETURN FALSE;
Error Message
- Error Message: err msg
- Associated Item: P1_X
Conditionals
- When Button Pressed: GOERRNULL (Go invalid)
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> PROC VALIDATION Delta CONDITION'); RETURN TRUE;
13. I created a process
Name
- Name: Gamma
- Type: PL/SQL anonymous block
Process Point
- Process Point: On Submit - Before Computation and Validations
- Run Process: Once Per Page Visit (Default)
Source
- Process: wwv_flow.debug('> PROC PROC Gamma SOURCE');
Conditional Processing
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> PROC PROC Gamma CONDITION'); RETURN TRUE;
14. I created a second process
Name
- Name: Epsylon
- Type: PL/SQL anonymous block
Process Point
- Process Point: On Submit - After Computation and Validations
- Run Process: Once Per Page Visit (Default)
Source
- Process: wwv_flow.debug('> PROC PROC Epsylon SOURCE');
Conditional Processing
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> PROC PROC Epsylon CONDITION'); RETURN TRUE;
15. I created a branch
Point
- Branch Point: On Submit: After Processing (After Computation, Validation and Processiong)
Action
- Target Type: Page in this Application
- Page: 1
- include process success message: checked
Conditions
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: wwv_flow.debug('> PROC BRANCH P1 CONDITION'); RETURN TRUE;
As can be seen, I've programmed all condition to be true and therefore making all objects do thier calculations.
Here is the debug output when we click on "Go". (a line number was added for easy refence)
{color:#999999}001 0.05: A C C E P T: Request="GO"
002 0.09: Metadata: Fetch application definition and shortcuts
003 0.09: NLS: wwv_flow.g_flow_language_derived_from=FLOW_PRIMARY_LANGUAGE: wwv_flow.g_browser_language=en-us
004 0.09: alter session set nls_language="AMERICAN"
005 0.09: alter session set nls_territory="AMERICA"
006 0.09: NLS: CSV charset=WE8MSWIN1252
007 0.09: ...NLS: Set Decimal separator="."
008 0.09: ...NLS: Set NLS Group separator=","
009 0.09: ...NLS: Set date format="DD-MON-RR"
010 0.09: ...Setting session time_zone to -05:00
011 0.09: ...Determine if user "FORD10" workspace "80447903191151509" can develop application "202" in workspace "80447903191151509"
012 0.09: Session: OK to reuse builder session for user:APEX_PUBLIC_USER
013 0.09: Fetch session state from database
014 0.10: ...Check session 2800365259756461 owner
015 0.10: ...Metadata: Fetch Page, Computation, Process, and Branch
016 0.10: Session: Fetch session header information
017 0.10: ...Metadata: Fetch page attributes for application 202, page 1
018 0.10: ...Validate item page affinity.
019 0.10: ...Validate hidden_protected items.
020 0.10: ...Check authorization security schemes
021 0.10: Session State: Save form items and p_arg_values
022 0.10: ...Session State: Save Item "P1_X" newValue="RENDER ITEM P1_X DEFAULT POST-CALCUL" "escape_on_input="N"
023 0.10: ...Session State: Saved Item "P1_Y" New Value="RENDER CALCUL P1_Y SOURCE POST_CALCUL"
024 0.10: Processing point: ON_SUBMIT_BEFORE_COMPUTATION
025 0.11: {color}{color:#ff9900}> PROC PROC Gamma CONDITION{color}{color:#999999}
026 0.11: ...Process "Gamma": PLSQL (ON_SUBMIT_BEFORE_COMPUTATION) wwv_flow.debug('> PROC PROC Gamma SOURCE');
027 0.11: {color}{color:#ff9900}> PROC PROC Gamma SOURCE{color}{color:#999999}
028 0.11: Branch point: BEFORE_COMPUTATION
029 0.11: Computation point: AFTER_SUBMIT
030 0.11: ...Evaluate condition "FUNCTION_BODY" for computation of item: P1_Y
031 0.11: {color}{color:#ff9900}> PROC CALCUL P1_Y CONDITION{color}{color:#999999}
032 0.11: ...Perform computation of item: P1_Y, type=FUNCTION_BODY
033 0.11: ...Performing function body computation
034 0.12: {color}{color:#ff9900}> PROC CALCUL P1_Y SOURCE{color}{color:#999999}
035 0.12: ...Session State: Saved Item "P1_Y" New Value="PROC CALCUL P1_Y SOURCE"
036 0.12: ...Evaluate condition "FUNCTION_BODY" for computation of item: P1_X
037 0.12: {color}{color:#ff9900}> PROC CALCUL P1_X CONDITION{color}{color:#999999}
038 0.12: ...Perform computation of item: P1_X, type=FUNCTION_BODY
039 0.12: ...Performing function body computation
040 0.12: {color}{color:#ff9900}> PROC CALCUL P1_X SOURCE{color}{color:#999999}
041 0.12: ...Session State: Saved Item "P1_X" New Value=""
042 0.12: Tabs: Perform Branching for Tab Requests
043 0.12: Branch point: BEFORE_VALIDATION
044 0.12: Perform validations:
045 0.12: {color}{color:#ff9900}> PROC VALIDATION Delta CONDITION{color}{color:#999999}
046 0.12: ...PL/SQL "function body returning boolean" Validation: wwv_flow.debug('> PROC VALIDATION Delta SOURCE'); RETURN :REQUEST 'GOERRNULL';
047 0.12: {color}{color:#ff9900}> PROC VALIDATION Delta SOURCE{color}{color:#999999}
048 0.13: Branch point: BEFORE_PROCESSING
049 0.13: Processing point: AFTER_SUBMIT
050 0.13: {color}{color:#ff9900}> PROC PROC Epsylon CONDITION{color}{color:#999999}
051 0.13: ...Process "Epsylon": PLSQL (AFTER_SUBMIT) wwv_flow.debug('> PROC PROC Epsylon SOURCE');
052 0.13: {color}{color:#ff9900}> PROC PROC Epsylon SOURCE{color}{color:#999999}
053 0.13: Branch point: AFTER_PROCESSING
054 0.13: ...Evaluating Branch: AFTER_PROCESSING type: "REDIRECT_URL" button: (No Button Pressed) branch: wwv_flow.debug('> PROC BRANCH P1 C5NDITION'); RETURN TRUE;
055 0.14: {color}{color:#ff9900}> PROC BRANCH P1 CONDITION{color}{color:#999999}
0.00:
0.00: S H O W: application="202" page="1" workspace="" request="" session="2800365259756461"
0.00: Language derived from: FLOW_PRIMARY_LANGUAGE, current browser language: en-us
056 0.00: alter session set nls_language="AMERICAN"
057 0.00: alter session set nls_territory="AMERICA"
058 0.00: NLS: CSV charset=WE8MSWIN1252
059 0.00: ...NLS: Set Decimal separator="."
060 0.00: ...NLS: Set NLS Group separator=","
061 0.00: ...NLS: Set date format="DD-MON-RR"
062 0.01: ...Setting session time_zone to -05:00
063 0.01: NLS: Language=en-us
064 0.01: Application 202, Authentication: CUSTOM2, Page Template: 2204612885682472
065 0.01: ...Determine if user "FORD10" workspace "80447903191151509" can develop application "202" in workspace "80447903191151509"
066 0.01: ...ok to reuse builder session for user:APEX_PUBLIC_USER
067 0.01: ...Application session: 2800365259756461, user=APEX_PUBLIC_USER
068 0.01: ...Determine if user "FORD10" workspace "80447903191151509" can develop application "202" in workspace "80447903191151509"
069 0.01: Session: Fetch session header information
070 0.01: ...Metadata: Fetch page attributes for application 202, page 1
071 0.01: Fetch session state from database
072 0.01: Branch point: BEFORE_HEADER
073 0.01: Fetch application meta data
074 0.02: Computation point: BEFORE_HEADER
075 0.02: ...Evaluate condition "FUNCTION_BODY" for computation of item: P1_Y
076 0.02: {color}{color:#ff9900}> RENDER CALCUL P1_Y CONDITION{color}{color:#999999}
077 0.02: ...Perform computation of item: P1_Y, type=FUNCTION_BODY
078 0.02: ...Performing function body computation
079 0.02: {color}{color:#ff9900}> RENDER CALCUL P1_Y SOURCE{color}{color:#999999}
080 0.02: ...Session State: Saved Item "P1_Y" New Value="RENDER CALCUL P1_Y SOURCE"
081 0.02: Processing point: BEFORE_HEADER
082 0.02: {color}{color:#ff9900}> RENDER PROC Beta CONDITION{color}{color:#999999}
083 0.02: ...Process "Beta": PLSQL (BEFORE_HEADER) wwv_flow.debug('> RENDER PROC Beta SOURCE');
084 0.02: {color}{color:#ff9900}> RENDER PROC Beta SOURCE{color}{color:#999999}
085 0.02: Show page template header
086 0.03: Computation point: AFTER_HEADER
087 0.03: Processing point: AFTER_HEADER
088 0.03: Computation point: BEFORE_BOX_BODY
089 0.03: Processing point: BEFORE_BOX_BODY
090 0.03: Region: Alpha
091 0.03: {color}{color:#ff9900}> RENDER REGION Alpha CONDITION{color}{color:#999999}
Alpha
092 0.03: {color}{color:#ff9900}> RENDER BUTTON Go CONDITION{color}{color:#999999}
093 0.03: {color}{color:#ff9900}> RENDER BUTTON Go invalid CONDITION{color}{color:#999999}
094 0.03: {color}{color:#ff9900}> RENDER BUTTON Reset CONDITION{color}{color:#999999}
Go Go invalid Reset cache
095 0.03: {color}{color:#ff9900}> RENDER ITEM P1_X CONDITION{color}{color:#999999}
096 0.03: > P1_X=""
097 0.03: {color}{color:#ff9900}> RENDER ITEM P1_X READ_ONLY CONDITION{color}{color:#999999}
098 0.03: Item: P1_X TEXT
099 0.03: {color}{color:#ff9900}> RENDER ITEM P1_X SOURCE{color}{color:#999999}
100 0.03: {color}{color:#ff9900}> RENDER ITEM P1_X DEFAULT{color}{color:#999999}
X RENDER ITEM P1_X DEFAULT POST-CALCUL
101 0.03: {color}{color:#ff9900}> RENDER ITEM P1_Y CONDITION{color}{color:#999999}
102 0.03: > P1_Y="RENDER CALCUL P1_Y SOURCE"
103 0.04: {color}{color:#ff9900}> RENDER ITEM P1_Y READ-ONLY CONDITION{color}{color:#999999}
104 0.04: Item: P1_Y TEXT
Y RENDER CALCUL P1_Y SOURCE POST_CALCUL
105 0.04: {color}{color:#ff9900}> RENDER REGION Alpha SOURCE{color}{color:#999999}
106 0.04: Computation point: AFTER_BOX_BODY
107 0.04: Processing point: AFTER_BOX_BODY
108 0.04: Computation point: BEFORE_FOOTER
109 0.04: Processing point: BEFORE_FOOTER
110 0.04: Show page tempate footer
111 0.04: Computation point: AFTER_FOOTER
112 0.04: Processing point: AFTER_FOOTER
113 0.04: Log Activity:
114 0.04: Execute Count=0
115 0.04: End Show:{color}
Here is the debug output when we click on "Go invlid". (a line number was added for easy refence)
{color:#999999}201 0.14: A C C E P T: Request="GOERRNULL"
202 0.19: Metadata: Fetch application definition and shortcuts
203 0.19: NLS: wwv_flow.g_flow_language_derived_from=FLOW_PRIMARY_LANGUAGE: wwv_flow.g_browser_language=en-us
204 0.19: alter session set nls_language="AMERICAN"
205 0.19: alter session set nls_territory="AMERICA"
206 0.19: NLS: CSV charset=WE8MSWIN1252
207 0.19: ...NLS: Set Decimal separator="."
208 0.20: ...NLS: Set NLS Group separator=","
209 0.20: ...NLS: Set date format="DD-MON-RR"
210 0.20: ...Setting session time_zone to -05:00
211 0.24: ...Determine if user "FORD10" workspace "80447903191151509" can develop application "202" in workspace "80447903191151509"
212 0.24: Session: OK to reuse builder session for user:APEX_PUBLIC_USER
213 0.24: Fetch session state from database
214 0.29: ...Check session 2800365259756461 owner
215 0.29: ...Metadata: Fetch Page, Computation, Process, and Branch
216 0.29: Session: Fetch session header information
217 0.29: ...Metadata: Fetch page attributes for application 202, page 1
218 0.30: ...Validate item page affinity.
219 0.30: ...Validate hidden_protected items.
220 0.30: ...Check authorization security schemes
221 0.30: Session State: Save form items and p_arg_values
222 0.31: ...Session State: Saved Item "P1_X" New Value="RENDER ITEM P1_X DEFAULT POST-CALCUL"
223 0.31: ...Session State: Saved Item "P1_Y" New Value="RENDER CALCUL P1_Y SOURCE POST_CALCUL"
224 0.31: Processing point: ON_SUBMIT_BEFORE_COMPUTATION
225 0.32: {color}{color:#ff9900}> PROC PROC Gamma CONDITION{color}{color:#999999}
226 0.32: ...Process "Gamma": PLSQL (ON_SUBMIT_BEFORE_COMPUTATION) wwv_flow.debug('> PROC PROC Gamma SOURCE');
227 0.32: {color}{color:#ff9900}> PROC PROC Gamma SOURCE{color}{color:#999999}
228 0.33: Branch point: BEFORE_COMPUTATION
229 0.33: Computation point: AFTER_SUBMIT
230 0.33: ...Evaluate condition "FUNCTION_BODY" for computation of item: P1_Y
231 0.34: {color}{color:#ff9900}> PROC CALCUL P1_Y CONDITION{color}{color:#999999}
232 0.34: ...Perform computation of item: P1_Y, type=FUNCTION_BODY
233 0.34: ...Performing function body computation
234 0.34: {color}{color:#ff9900}> PROC CALCUL P1_Y SOURCE{color}{color:#999999}
235 0.34: ...Session State: Saved Item "P1_Y" New Value="PROC CALCUL P1_Y SOURCE"
236 0.34: ...Evaluate condition "FUNCTION_BODY" for computation of item: P1_X
237 0.34: {color}{color:#ff9900}> PROC CALCUL P1_X CONDITION{color}{color:#999999}
238 0.34: ...Perform computation of item: P1_X, type=FUNCTION_BODY
239 0.34: ...Performing function body computation
240 0.35: {color}{color:#ff9900}> PROC CALCUL P1_X SOURCE{color}{color:#999999}
241 0.35: ...Session State: Saved Item "P1_X" New Value=""
242 0.35: Tabs: Perform Branching for Tab Requests
243 0.35: Branch point: BEFORE_VALIDATION
244 0.35: Perform validations:
245 0.75: {color:#ff9900}> PROC VALIDATION Delta CONDITION{color}{color:#999999}
246 0.76: ...PL/SQL "function body returning boolean" Validation: wwv_flow.debug('> PROC VALIDATION Delta SOURCE'); RETURN FALSE;
247 0.78: {color}{color:#ff9900}> PROC VALIDATION Delta SOURCE{color}{color:#999999}
248 0.78: ...{color}{color:#ff0000}Validation did NOT pass{color}{color:#999999}
249 0.78: ...{color}{color:#ff0000}Inline validation error count = 1{color}{color:#999999}
250 0.86: Show current page with inline validations
251 0.87:
252 0.87: S H O W: application="202" page="1" workspace="" request="" session="2800365259756461"
253 0.87: NLS: Language=en-us
254 0.87: Application 202, Authentication: CUSTOM2, Page Template: 2204612885682472
255 0.88: ...Determine if user "FORD10" workspace "80447903191151509" can develop application "202" in workspace "80447903191151509"
256 0.88: ...ok to reuse builder session for user:APEX_PUBLIC_USER
257 0.88: ...Application session: 2800365259756461, user=APEX_PUBLIC_USER
258 0.88: ...Determine if user "FORD10" workspace "80447903191151509" can develop application "202" in workspace "80447903191151509"
259 0.88: ...Metadata: Fetch page attributes for application 202, page 1
260 0.88: Branch point: BEFORE_HEADER
261 0.88: Fetch application meta data
262 0.88: Computation point: BEFORE_HEADER
263 0.88: ...Evaluate condition "FUNCTION_BODY" for computation of item: P1_Y
264 0.92: {color}{color:#99cc00}> RENDER CALCUL P1_Y CONDITION{color}{color:#999999}
265 0.92: Processing point: BEFORE_HEADER
266 0.92: ......Do not perform process because inline validation condition found.
267 0.92: ...Do not run process "Beta", process point=BEFORE_HEADER, condition type=FUNCTION_BODY, when button pressed=
268 0.92: ...Recompute field lables for fields in error.
269 0.97: Show page template header
270 1.20: Computation point: AFTER_HEADER
271 1.20: Processing point: AFTER_HEADER
1 error has occurred
* Error msg
272 1.20: Computation point: BEFORE_BOX_BODY
273 1.20: Processing point: BEFORE_BOX_BODY
274 1.21: Region: Alpha
275 1.23: {color}{color:#ff9900}> RENDER REGION Alpha CONDITION{color}{color:#999999}
Alpha      
276 1.25: {color}{color:#ff9900}> RENDER BUTTON Go CONDITION{color}{color:#999999}
277 1.25: {color}{color:#ff9900}> RENDER BUTTON Go invalid CONDITION{color}{color:#999999}
278 1.28: {color}{color:#ff9900}> RENDER BUTTON Reset CONDITION{color}{color:#999999}
Go Go invalid Reset cache
279 1.30: {color}{color:#ff9900}> RENDER ITEM P1_X CONDITION{color}{color:#999999}
280 1.30: > P1_X=""
281 1.30: {color}{color:#ff9900}> RENDER ITEM P1_X READ_ONLY CONDITION{color}{color:#999999}
282 1.30: Item: P1_X TEXT
X POST-CALCUL
Error msg
283 1.30: {color}{color:#ff9900}> RENDER ITEM P1_Y CONDITION{color}{color:#999999}
284 1.30: > P1_Y="PROC CALCUL P1_Y SOURCE"
285 1.31: {color}{color:#ff9900}> RENDER ITEM P1_Y READ-ONLY CONDITION{color}{color:#999999}
286 1.31: Item: P1_Y TEXT
Y PROC CALCUL P1_Y SOURCE POST_CALCUL
287 1.32: {color}{color:#ff9900}> RENDER REGION Alpha SOURCE{color}{color:#999999}
288 1.32: Computation point: AFTER_BOX_BODY
289 1.32: Processing point: AFTER_BOX_BODY
290 1.32: Computation point: BEFORE_FOOTER
291 1.32: Processing point: BEFORE_FOOTER
292 1.32: Show page tempate footer
293 1.32: Computation point: AFTER_FOOTER
294 1.32: Processing point: AFTER_FOOTER
295 1.32: Log Activity:
296 1.32: Execute Count=0
297 1.32: End Show:{color}
Looking at those debug output, I was able to find a workaround. Look at the line 264 and compare that to the lines 076 to 080. What I did is put the computation in the condition. This way, I'm garanteed that the calculation is always done. Here is an exemple:
A Computation (in the Page Rendering part)
Item Name
- Item Name: P1_Y
- Type: PL/SQL Function body
Computation Point
- Computation Point:After Submit
Source
- Computation: RETURN :P1_Y; -- Never executed. Look in the condition for computation
Conditional Computations
- Condition Type: PL/SQL Function Body Returning a Boolean
- Expression 1: :P1_Y := COMPUTE(); RETURN FALSE;
This works but totally break the semantics created in APEX.
Suggestion:
In the Page rendering phase, when a validation fails, the source compution found in a Item (in that case the value is taken from the session state), in a Computation or in Process is never executed.
This should revised.
Their should be a way for the programmer to choose what behavior the rendering phase will have when a validation fails other than using a workaround that might break in futur versions of APEX.
Edited by: user4591233 on Nov 19, 2008 6:32 AM
Edited by: user4591233 on Nov 19, 2008 6:34 AM

Answer 1

Dominique,
Thank you for the detailed problem description. Although you posted it some ten hours ago I have just now finished reading it.
Form pages must be built so they can operate correctly when inline validation errors are displayed. The assumption (by the engine) is that session state (and package state) as it exists at the point the validations are performed is sufficient (and correct) to support the redisplay of the page without the need to fire on-load processes or computations. Session state or package state changes made by after-submit computations or after-submit/before computations/validations processes that prevent correct page behavior on the "validation redisplay" must be avoided.
The condition types Inline Validation Errors Displayed/No Inline Validation Errors Displayed can be used for on-load events/controls (processes, computations, regions, items, ...) for which you need finer control over this behavior.
Also, you can forgo the use of after-submit computations when the resulting alteration of session state would be inimical to proper "validation redisplay" behavior and use On Submit - After Computations and Validations processes instead.
I hope I have understood your situation and that this answer adequately answers your questions.
Scott