Element session state Question

Hi
I have built a parametrized report using an Element P4_JOB and by clicking on a Button, Some Employees Data should be displayed in a Region.
my Problem is i want to reset the Value for the Element P4_JOB when the Buton is clicked and the result is diplayed.
how to achieve that?
br.
MDK.

I think you'll need to clear the item when the page is being rendered to show the results. If you try to clear it earlier it won't get set into session state and be picked up by the reporting query.
You could set the source for the item to be static text and leave the source empty, and also it so that it resets the item's contents on each page load rather than when it's value is null (sorry I can't remember the exact wording on the apex builder)

Similar Messages

How to update session state from form field values without submitting page?

Hi,
I am new to Oracle APEX. I am using Oracle Apex 4.2 on Oracle 11g release 2. The problem is that when I am entering data on a form, when I enter a value in one field and move to the next field, how can I use the value of first field in the validation procedure of next field? I know that when we enter data in fields, the session state is not updated with these values until we submit the page... right... but I have seen that if there is a control of List box type, then Apex gives an option "Action When List changes" where we can choose option to update corresponding session state field with the value of list box item, without submitting the page.
Now my questions is why this option is only available for List box items? why not for other item types like Text box, Check box,... ? can someone please help me with this?
(the issue with update of session state depending on page submitting, is that we need a complete network round trip from client to server in order for it. However if we can update session state variables without submitting page, then we can avoid this network traffic).
Any help will be greatly appreciated. Thanks in advance.

Create a dynamic action on change and run a PL/SQL process there with the following code:
BEGIN
NULL;
END;Page items to submit > your item.
This will set the session state without submitting the form.
Further examples here:
http://apex.oracle.com/pls/apex/f?p=31517:229
Denes Kubicek
http://deneskubicek.blogspot.com/
http://www.apress.com/9781430235125
http://apex.oracle.com/pls/apex/f?p=31517:1
http://www.amazon.de/Oracle-APEX-XE-Praxis/dp/3826655494
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Row fetching, session state, multi-page processing of 1 row - problems

I'm building an application that's updating a couple of tables via an updateable view and an instead-of trigger. That portion of it works OK, EXCEPT for the problems that I'm having with the APEX end.
I've got 3 pages; the first page reads the row in via the automated row fetch and has, say columns 1-20.
Page 2 has, say, columns 20-40 and page 3 has the remainder.
I have the row fetch set up conditionally so that it only executes the first time that page 1 is displayed. All the columns are set as Database Columns.
It seems that if I fill in fields on page 1, move to page 2, and back to page 1, the contents of the fields on page 1 are destroyed unless I set their 'Source used' to 'Only when the current value in session state is null'.
Furthermore, upon update (which is on page 3, via an automated row update), the only columns that get updated are those that exist on page 3. The column values from the other pages no longer exist.
Does navigation to another page not retain the session-state of database-column items?
Am I better off just writing my own processes to perform the updates?
Any other suggestions?
Frank

Hello Frank,
>>I have the row fetch set up conditionally so
that it only executes the first time that page 1 is
displayed …
It seems that if I fill in fields on page 1, moveto page 2, and back to page 1, the contents of the
fields on page 1 are destroyed unless I set their
'Source used' to 'Only when the current value in
session state is null'.
It seems that the first sentence is not consistent
with the second one. The only reason the values are
destroyed, as you call it, is that the ARF is running
again. What condition are you using on your ARF?
In any case, the right way to deal with it is to
change the source used to "Only …", as I understand
you already did.
Hi Arie,
I set an item after the first ARF. I then have the ARF set to execute conditionally based on the presence of that item. (I also display a success message on the ARF, so I know that the ARF is only occurring once). I move to subsequent pages by submitting the current pages.
>>Does navigation to another page not retain the
session-state of database-column items?
Navigating to another page does retain the session state values.
It's depends on what you mean by navigating.
Submitting the page set/update session state.
Redirect without submitting the page will not
set/update the session state.
>>Furthermore, upon update (which is on page 3,
via an automated row update), the only columns that
get updated are those that exist on page 3. The
column values from the other pages no longer
exist.
Automatic DML is working only with the current page
items. You can't use it to insert/update other page
items, even if they are in session state. However, in
your case, it's not the Automatic DML performing the
actual updates, but your triggers. Are your triggers
relying on session state values?
I think this statement 'Automatic DML is working only with the current page
items.' answers my question. My trigger is working on session state values. It's an 'instead-of' trigger, so I was letting the automatic DML perform the 'update' on the view, while allowing the trigger to do the actual update of several tables that the view joins by referring to their :NEW. values in the trigger. Since the DML occurs on my last page, those were the only session state values that my trigger ultimately saw.
>>Am I better off just writing my own processes to
perform the updates?
I believe the correct way is to submit the page and
then branch to the next one. Submitting the page will
save all your items in session state, and allow these
items to be available for page 3 DML.
Regards,
Arie.I'm doing that already - all the values do appear to be in session sate, except only the items that are on the last page actually make it to the automatic DML update, which seems to agree with your previous statement.
I suppose I could write my own process to perform the update, as the values are available in session state.
Thanks,
Frank

Saving session state in database table rather in websever for Ordering App

Hi all,
Ours is a ordering application (telecomm) domain.
Currently, we are storing user sessions data (Order shopping cart session data) in middle tier (iPlanet web server) which inturn consumes lot of memory resources.
Shopping cart could be in MBs if order is a huge business order.
So in order to not to overtax web server (middle tier), we are thinking of storing session data directly in a database table to relieve the overhead on web server and make use of database for storage.
I read that APEX (html db) is already using this "single metadata table" approach for session data management. But we are not using HTML DB to really look into.
Can some one advise how to go about storing "user session data" directly in a "database table" for both storage and retrieval purposes instead of storing it in "webserver".
How does this "metadata table" structure looks like. Is it more generic ?
Really appreciate your time and help/suggestions.

Joel,
Thanks for your response. sorry, i meant to say that "the current application does not use APEX but will look into it".
To build this is an utterly non-trivial exercise. Oh - it may not be so hard to save session state to a table when you POST a page. But you may want to reference this in many places, and it's a question of can you change all of these references to indirect references from session state in your application.In order to free up the load on webserver, we want to maintain session management in database. Could you please explain the above little more :
How do we maintain the "user session" with "database table" ?
Do we need to store "session data" at java object level or by page in database table ? How does the structure of this "metadata table" looks like.
Thanks for your time.

Session state protection and read-only items

I have a requirement to create a report + form for a database table. In the form, there is mandatory database column that needs to be displayed but it should be read-only and its value derived using values entered elsewhere on the screen.
It tried Display Only, Read Only and Disabled but they either fall foul of session state protection violation or ORA-01400: cannot insert NULL. The best method that I've found was to add readonly="readonly" the item element, but this causes the input item to lose its APEX classes and I'd prefer a declarative solution anyway.
Anyone know the best approach?
I've created a DEMO - http://apex.oracle.com/pls/apex/f?p=READONLY - which demonstrates the 4 methods.
Edited by: KGelling on 17-May-2012 06:10

KGelling wrote:
The best method that I've found was to add readonly="readonly" the item element, but this causes the input item to lose its APEX classes and I'd prefer a declarative solution anyway.Looks like a bug to me. However a possible explanation/justification for this behaviour is that the HTML Form Element Attributes are often used to specify a custom class for the item, so the default class is removed to prevent any conflicts. IMO APEX needs to provide declarative support for the use of multiple, space-separated class values in page, region, item etc attributes.
As a workaround in this case, just include the class in the HTML Form Element Attributes:
class="number_field" readonly="readonly"
I've created a DEMO - http://apex.oracle.com/pls/apex/f?p=READONLY - which demonstrates the 4 methods.
Thanks for making the effort.

Application Items/Session State Values and Page Branching

I have users coming into a specific page in my application, passing in a value on the url that sets the value of an application item, where a validation routine occurs. If their session validates, I want to send them to one page, if it does not, I want to send them to a login error page.
During validation, I am setting the values of several application items so that these values can be saved and used throughout their session. The values appear to be setting correctly. I am concerned that setting the application items may not be limiting these values to a particular session. So, I have also tried setting the setting session state variables with code like:
apex_util.set_session_state ('F203_REQ', vReqID);
I found it curious though when I ran this page, not trying to branch so I could check session state, these values showed up as being application items and I saw nothing under session variables.
The problem I am having is that once validated I don't know how to branch to these other pages. I have tried adding some javascript in the header to force a page submit so that I could use a branch setup on the page. However, when it comes time to evaluate the branches (it's using one of the application item values I set earlier), I'm getting an error that no branch has been provided. Further research suggests the application item values are being cleared on the page submit.
So, (1) I either need to know how to preserve those values on submit so the page branch works or (2) I need to branch to the new page without using a page submit and instead doing that in a some code (assuming submit is clearing application item values). I have not been able to find an example of how to do this in code. If there is a way to do this in code, will the application item or session state variable values be retained? I will need these values to be available to the user throughout their session.
Thanks for the help,
Steve

Steve,
I am concerned that setting the application items may not be limiting these values to a particular session.They are set in the current session only.
It is hard to know what you are doing exactly without seeing it. If you set up an example on apex.oracle.com we could could address one specific question at at time.
Scott

Session State Values Only Used After a Page Refresh

We recently moved our application to use Oracle Application Server. I don't know if this is an issue but I thought it might be relevant to my question.
In this application there is report that has a link to another page. This link sets the ID of the company that the subsequent pages use to provide several summarized reports with drill downs. I'll call this the main page.
Users recently started to report that when they drill into the details and use the breadcrumbs to get back to the main page, that page will display the wrong company, one they were viewing recently.
In testing I find that when I click a link to drill down into the details the details page is not for the right company. I check session state and the value of the ID is correct. If I refresh the page I then get the correct drill down page. Some of the drill down reports will pass a page specific ID into each page and others will just reference the ID from the main page. Not sure if this is relevant since the breadcrumbs to go back to the main page would not be able to use every possible page specific ID, my understanding was that once I set the ID in session state on the main page I could rely on it.
Also if I get the wrong details page and click on the breadcrumb to the main page I get the wrong main page (it displays a previously viewed company). Again the session value is correct and a refresh of the page will bring back the right company.
Our systems admin was asked to check if we had WebCache on and she said it was not. Is there something else that could be caching the results of these pages?
Thanks,
Greg

Scott,
This is in version 2.2.1 and there are no caching features available.
The application does require login.
I'm playing around with the APP_UNIQUE_PAGE_ID right now but I am finding that even in the builder if I edit the attributes of a report column and then try to edit another column it will bring up the last column I edited. Even if I use the record navigation buttons next to the Apply Changes button it will keep bringing me the same page over and over unless I constantly refresh the pages.
Greg

Controlling Session State and Submit Processing

I am trying to gain a fundamental understanding of how to control submit processing and session state, etc.
For example, I have a popup lov that lists names and returns id for the parent record. When the user make the selection using this pop lov, I then have an id that I want to use to lookup the default value for another field.
How do you submit a page for re-rendering (i.e, you have condition expressions referencing values that the use has set) without triggering the auto dml and page branch?
For example, I have a form for specifying tns names with 2 buttons, 'Advanced Config' and 'Basic Config'. The idea is to hide/show items corresponding to basic or adv. config options, etc.
My first approach was to have the buttons do a redirect to the same page, setting P5_USE_ADV_CONFIG_YN to Y or N without clearing the cache. When the page refreshes, the conditional rending has occured as desired (i.e., I set the condition on my form items to reference P5_USE_ADV_CONFIG = Y or N, etc.), but user's data values have been lost since the record was reloaded from the database.
So..I tried putting a condition on the fetch procedure to prevent the record from being re-read. However, this left all the fields empty which indicates that the item's session state has been completed cleared! Huh? I didn't want ask for or want this behavior. Hmmm.
So, I start thinking that the persisted session wasn't updated since I didn't do a submit and so when the page was requested, it behaved as it should, but not what I had in mind. THUS...I believe I need to submit the page and prevent the auto-dml and page branching afterwards....but how? I feel that I am missing something very fundamental here and that the answer may also help me with other related questions:
* How does the confirm delete examples work? How is the processing stopped when the user presses cancel?
* How can you do validations and stop dml processing without losing the user values?
* How can you display and error page and then return to where the user was with the values still present?
* How can I do a secondary sql value lookup based on the users selection in a popup lov? (User selects a Database/DbID - then I want to lookup host using DbId)
I haven't been successful understanding this from the manuals, but someone can point me to some material that explains submit processing, redirects, etc. I would be happy to do some more digging.
Thanks greatly in advance.

Thanks Scott,
I may be being dumb here but I don't see how that would help...
P250_PROJECT and G_PROJECT are currently kept in sync by app logic. Whichever is used to drive, if the page is rendered from cache then the app logic is not executed, so the rendered page contents are not those keyed by P250_PROJECT, as illustrated in steps 1-4 of the problem above.
The user sees X, the session items say Y. The engine doesn't know what the user is seeing.
when page P is POSTed, its hidden item P250_PROJECT should always be used to derive the application item G_PROJECT. Then whether the page was pulled from cache or rendered anew via a click from the sidebar link, the project ID is determined by the contents of that page.
As I said above I tried this, with the 'Edit' branch set to:
Set these items: G_PROJECT
With these values: &P250_PROJECT.
but it makes no difference. The project ID is not determined by the rendered page contents - the engine gets the value of P250_PROJECT from session state.
I can code the 'Edit' pages such that they check permissions and if necessary redirect back to p250 (conditional before-header branch), but that's a clunky cure rather than the prevention I was hoping for.
Please tell me if my understanding is incorrect.
jd

??? On Session State

Background info:
I have a field that could have two different types of input, one would be numeric (such as a PK) the other input to it would be text. To ensure the Automated Row Fetch always pulls the PK properly I am using a computation ON LOAD to turn the text into numeric so that when the Automatic Page Load runs it will always pull from the database based on the PK.
This part is working properly the problem is that I have an item that is a select list and it unforunately has an dynamic LOV with a query of select a,b from table_xyz where value = :session_state_of_pk
This is causing me a problem because it is referencing the "text value" and not the numeric value. Even though when I change my page view to "Events" the page rendering shows computations before Items. I even did a Pl/sql process ON LOAD to insert the :session_state value to a debug table.
So my question is ... If the pl/sql on load process is holding the correct value then why is the LOV of a page item not using the correct value??
This is the error I get on the page Item that is an LOV:Error: ORA-01722: invalid number performing List of Values query

Vikas, I have done this and here are the results:
.01: S H O W: application="110" page="103" workspace="" request="" session="6865688852817169"
0.01: Language derived from: FLOW_PRIMARY_LANGUAGE, current browser language: en-us
0.01: alter session set nls_language="AMERICAN"
0.01: alter session set nls_territory="AMERICA"
0.01: NLS: CSV charset=WE8MSWIN1252
0.02: ...NLS: Set Decimal separator="."
0.02: ...NLS: Set NLS Group separator=","
0.02: ...NLS: Set date format="DD-MON-RR"
0.02: ...Setting session time_zone to dbtimezone
0.02: NLS: Language=en-us
0.02: Application 110, Authentication: CUSTOM2, Page Template: 724212235889446
0.02: ...Supplied session ID can be used
0.02: ...Application session: 6865688852817169, user=JRP22
0.02: ...Determine if user "JRP22" workspace "1786101047996118" can develop application "110" in workspace "1786101047996118"
0.03: Session: Fetch session header information
0.03: Saving g_arg_names=P103_IP_ID and g_arg_values=077.243
0.03: ...Session State: Save Item "P103_IP_ID" newValue="077.243" </b<"escape_on_input="N"
0.03: ...Metadata: Fetch page attributes for application 110, page 103
0.03: Fetch session state from database
0.04: Branch point: BEFORE_HEADER
0.04: Fetch application meta data
0.04: Authorization Check: "6961000503551770" User: "JRP22" Component: "PAGE"
0.06: Computation point: BEFORE_HEADER
0.06: ...Perform computation of item: P103_IP_ID, type=QUERY
0.06: ...P103_IP_ID=select ip_id from IP where IP = :P103_IP_ID;
0.06: ...Session State: Saved Item "P103_IP_ID" New Value="32"
0.06: Processing point: BEFORE_HEADER
0.06: ...Process "TEST DB INSERT SESSION STATE P103_IP_ID": PLSQL (BEFORE_HEADER) insert into t (col1,col2,tstamp) values ('p395',:p103_ip_id,systimestamp);
0.08: Show page template header
0.09: Computation point: AFTER_HEADER
0.09: Processing point: AFTER_HEADER
0.09: ...Process "Fetch Row for IP": DML_FETCH_ROW (AFTER_HEADER) F|#OWNER#:IP:P103_IP_ID:IP_ID
0.10: ...Process "Fetch DNS_NAME To Buffer": PLSQL (AFTER_HEADER) :P103_DNS_NAME_BUFFER := :P103_DNS_NAME;
0.11: ...Session State: Save Item "P103_DNS_NAME_BUFFER" newValue="3657" "escape_on_input="N"
0.11: ...Process "Get Next or Previous Primary Key Value": GET_NEXT_OR_PREV_PK (AFTER_HEADER) #OWNER#:IP:IP_ID::IP::P103_IP_ID:P103_IP_ID_NEXT:P103_IP_ID_PREV::::P103_IP_ID_COUNT:
0.13: ...Session State: Save Item "P103_IP_ID_NEXT" newValue="33" "escape_on_input="N"
0.13: ...Session State: Save Item "P103_IP_ID_PREV" newValue="31" "escape_on_input="N"
0.14: ...Session State: Save Item "P103_IP_ID_COUNT" newValue="32 of 3434" "escape_on_input="N"
0.14: ...Process "Fetch MAC_ADDRESS": PLSQL (AFTER_HEADER) select mac_address into :P103_MAC_ADDRESS from mac_address where IP_ID = :P103_IP_ID;
0.15: ...Session State: Save Item "P103_MAC_ADDRESS" newValue="00-16-3G-33-25-33" "escape_on_input="Y"
0.15: ...Process "Fetch Container_Type": PLSQL (AFTER_HEADER) select container_type into :P103_CONTAINER_TYPE from container_type where container_type_id = :P103_CONTAINER_TYPE_ID;
0.16: ...Session State: Save Item "P103_CONTAINER_TYPE" newValue="BASE_UNIT" "escape_on_input="Y"
0.16: ...Process "Populate Hidden Assign value": PLSQL (AFTER_HEADER) :P103_ASSIGNED_BUFFER := :P103_ASSIGNED;
0.16: ...Session State: Save Item "P103_ASSIGNED_BUFFER" newValue="Y" "escape_on_input="N"
0.16: Authorization Check: "4769021032313739" User: "JRP22" Component: "tab"
From Session State after the page has loaded:
Application Page Item Name Display Item Value Status
110 103 P103_IP_ID Hidden 32 U
Vikas: From the debug info you can the value comes in with the the IP ( I have removed the first two octets from the debug information) "Saving g_arg_names=P103_IP_ID and g_arg_values=077.243"
A few steps later a computation is performed and the IP is chagned to an IP_ID which the value is 32, this is correct at this point.. Following that there is a pl/sql insert of :P103_IP_ID and that value is 32 inside the db table.
Here is what it looks like on the screen:
Any ideas why the Select List LOV does not like this value?
Here is the actual LOV query:
select dns_name,dns_name_id from dns_name where ip_id = :p103_ip_id
Message was edited by:
Justin P

Session State Protection Confusion!

Hello all,
I'm looking into SSP, and find it very confusing; there are so many ways to implement it, and I'm just not sure which I should choose.
I basically want to stop people tampering with the URL to change the values of variables and the like. I have currently enabled SSP for every page, which seems to work fine.
However, you can also do it for each item and application item; is this also necessary, or are these options only there if I only wanted to enable SSP for a very specific thing (item) rather than an entire page?
Does enabling SSP at page level protect the items (application and other) on that page in the same way enabling SSP for each of those items would do?
Also, are there any implications from using SSP? Will some things not work if I enable it in some instances?
Thanks for your help.
Robin

Robin,
These are all good questions.
What situations would arise when you'd want to use "No URL Access" for page access protection and "Restricted - May not be set from browser" for various item protections?
Sometimes you have pages that you would never want a user to "get to" unless they had used the navigation controls that you built into the application. For example, the intermediate steps within a wizard. You may have seen examples of this in the Application Builder as you step through wizards (and in other places) where you'll be on a page and in the URL all you see is ..wwv_flow.accept, with no f?p URL that tells you what page ID was requested. This is an example of a Branch to Page branch in use. This type of branch does not do a redirect to an f?p URL but instead has the engine's "accept" procedure (from the last page submission) call the engine's "show" procedure directly using PL/SQL without introducing a new HTTP request. So if you have pages like that and you use Branch to Page branches as the "normal" way to get to them AND you want to prevent users from specifying those page IDs in URLS, then this feature of Session State Protection is available to support that.
and how does the "Restricted - May not..." differ from the "Checksum Required - Session Level"; is that literally where a user can't alter the value of an item in the application, or is there more to it than that?
Restricted ... prevents an item from being altered from outside the application. The only way you can set or change these items is by application logic. This feature can be used for items even if Session State Protection is not enabled for the application.
Also, I can't understand just what user level and application level checksums would be useful for.
Normally, when SSP checksums are generated, they are good for the current session. Say you have a URL like:
f?p=100:55:ssssssss::NO::P1_ITEM,P2_ITEM:some-value-1,some-value2&cs=38DDFE1C102BDE167BCD66F4C2E77E16E
A curious user might say, oh, I think I'll bookmark that link and run it again tomorrow to set the same page items to the same values. Well that doesn't work because the checksum is session ID specific. This also makes the hashing algorithm more secure.
But sometimes you want to provide checksum-secured links that users can bookmark. Maybe you want to email a link to your application to a specific user and the link provides some key value that should be used by that specific user only (and you have authorization logic in the application to enforce that), like f?p...P10_USER_KEY:ABc568zz&cs=238DDFE1C102BDE167BCD66F4C2E77E16D. This is where the use of a User-Level checksum would be applicable. After the user clicks on the link and authenticates, the provided checksum can be verified against a new checksum computed on P10_USER_KEY:ABc568zz. These links can be used across sessions for this type of use but the checksum prevents alteration of the request arguments even by the intended user.
The third type of checksum is the Application-Level (or Workspace-Level) checksum. Links with this type of checksum can be used by any user so long as the requested application is really the same application from the same workspace that generated the link. The checksum prevents alteration of the request arguments by the user.
Scott

Session State Replication of Referenced Objects

Here is question on Clustering and Session state replication:
          Scenario:
          Consider two Session Objects A and B.
          Object A has-a reference to object B.
          So whatever changes done to Object B is reflected in Object A.
          In-memory Session replication happens on every HttpSession.setAttribute() call.
          The question is will the two session objects(A and B) be replicated to the other cluster and will still maintain the reference relationship or will they be two separate objects with same data (in different memory locations).
          regards,
          Jaiganesh

Ok, I have been meaning to dig into session replication in a bit more detail and your question is a good excuse to do it!
          First stop the docs:
          Bea Docs
          The bits that jump out are under:
          Programming Considerations for Clustered Servlets and JSPs
          1) Session Data Must Be Serializable, so both your objects are serializable.
          2) Use setAttribute to Change Session State In an HTTP servlet that implements javax.servlet.http.HttpSession, use HttpSession.setAttribute (which replaces the deprecated putValue) to change attributes in a session object. If you set attributes in a session object with setAttribute, the object and its attributes are replicated in a cluster using in-memory replication. If you use other set methods to change objects within a session, WebLogic Server does not replicate those changes. Every time a change is made to an object that is in the session, setAttribute() should be called to update that object across the cluster.
          Likewise, use removeAttribute (which, in turn, replaces the deprecated removeValue) to remove an attribute from a session object.
          >Will the reference as shown in the step 3 will be >maintained after replication on the other cluster ?? I >guess not!!
          I don't understand "on the other cluster" There is normally one cluster made up of a few servers. The session state is maintained on one primary server and a secondary server. So you have aObj.a2 = bObj, from the docs I would understand that at the momment you called session.setAttribute the aObj and all its fields provided they are seriliazable will be replicated in Mememory.
          >There the aObj and bObj stored in the two different >session objects will not have a reference relationship >in other words if i change bObj on the other cluster >will the reference a2 of aObj be able see it ??
          This is testing the limits of my understanding, but would have thought if the objects are in different sessions they should not be able to reference each other in the manner I think you are suggesting, so if I access aObj.a2 (an instance of bObj) and changed it in one session it should not affet any other bObj unless bObj is a singleton....I think!
          What say you?

Session State Protectio Violoation in Apex 4.2 Page Items

I'm testing my Apps that I upgraded from 3.2 to 4.2 and getting the message below and haven't been able to understand why.
Error Session state protection violation: This may be caused by manual alteration of protected page item P2_PAY_NO. If you are unsure what caused this error, please contact the application administrator for assistance
How the Page works.
1. Before Region Process runs that pre-populates some of my Text Items.
2. The user then has the ablibity to select from a select list item that will re-populate the items populated during the Before reqion based on the date selected.
I do this by calling the code below with an "onchange="javascript:date_populate(this);" on the HTML Form Elements Attributes.
{var myString = $x(pThis).value;
var mySplitResult = myString.split("|");
$x('P2_START_DATE').value = mySplitResult[0];
$x('P2_PAY_YEAR').value = mySplitResult[1];
$x('P2_PAY_NO').value = mySplitResult[2];
$x('P2_PICT_CODE').value = mySplitResult[3];
$x('P2_END_DATE').value = mySplitResult[4];}
3. When I submit the page I get the Session State Violation.
All Items have "Session State Proection" set to "Unrestricted"
Session State Protection is "Disabled" for the application.
Edited by: spuchc on Apr 12, 2013 2:07 PM

Check you are not updating items of type "Display Only".
Denes Kubicek
http://deneskubicek.blogspot.com/
http://www.apress.com/9781430235125
http://apex.oracle.com/pls/apex/f?p=31517:1
http://www.amazon.de/Oracle-APEX-XE-Praxis/dp/3826655494
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Apex bug? Items being cleared in session state - can't figure out why

I have an item that is being submitted with a value but is then being overwritten and set to null. I can't see any reason why the submitted value is being overwritten with null.
I have been debugging this problem for most of the day and can't figure out what is happening and was hoping someone in the forum might be able to shed some light.
Some details:
The item is on Page 0, has source type of "PL/SQL Expression or Function", a source expression of "V('REQUEST')", and Source Used = "Always".
I viewed the HTML source of the rendered page and can see the following HTML, so I know the item has a value when the page is rendered:
<input type="hidden" id="RENDER_REQUEST" name="p_t08" value="EDIT" />
I have used Firebug to view the HTTP POST body and can see that p_t08 is being correctly submitted with a value of "EDIT" in the post body.
When I run the page in debug mode and then view the debug log, I see that Apex is indeed setting this item to null:
 0.01500 0.01600 A C C E P T: Request="WIZ_NEXT"
 0.23400 0.00000 Session State: Save form items and p_arg_values
 0.24900 0.01600 ...Session State: Save "BRANCH_TO_PAGE_ID" - saving same value: ""
 0.24900 0.00000 ...Session State: Save "ROWS_PER_PAGE" - saving same value: ""
 0.26500 0.01500 ...Session State: Save "P0_CLEAR_WS" - saving same value: ""
 0.26500 0.00000 ...Session State: Saved Item "RENDER_REQUEST" New Value=""
I can't figure out why the item is being set to null.
This problem also does not occur on every page. The pages in question are a multi-step "wizard" that allows the user to navigate between steps with "Next" and "Previous" buttons. Since this is a page 0 item, it appears on every page in the wizard so I'd expect it to behave the same. When you open the wizard at step 1 and press next to go to step 2, the item (RENDER_REQUEST) is set correctly on step 2 of the wizard, BUT when you then click Next to go to step 3, RENDER_REQUEST is null on step 3. If you open the wizard at step 2 and press Next, RENDER_REQUEST is null on step 3.
I did find a work around, but it doesn't make any sense why it would work: if I move the RENDER_REQUEST item from the "Footer Items" region to a page level item (by using Edit All and setting its region to blank), then the problem goes away. If I move it back to the "Footer Items" region the problem reoccurs.
I am working on Application Express 4.0.2.00.07 on Oracle Database 11g Enterprise Edition Release 11.2.0.1.0.
Any help would be greatly appreciated!
Thank you.

Hi Patrick,
Thanks for the quick response. Unfortunately, I can't reproduce this on apex.oracle.com due because the app requires PL/SQL packages to be installed in several schemas, including some that require system grants (I gave a presentation at Oracle Open World a couple of years ago on some of the techniques I used in building this application that you attended; I think the session was called "Building Large Commercial Applications with Oracle Database 11g and Oracle Application Express").
Is there another way we can work together to debug this without reproducing it apex.oracle.com? For example, if you could send me an instrumented version of the APEX_040000.F procedure (or whatever procedure is clearing the session state) that has some additional APEX_APPLICATION.DEBUG calls, I could install it on my server, reproduce the error and send you the output.
Thank you,
Eric

Format Mask in Session state

In a Summary Region (Page 6) I have changed one field to text, edited the field with no format mask. In the entry form on the pervious page, the column properties are Database Column, and Always replace value in Session State with the Money format Mask.(Page 5).
10313 5 P5_LPP Text $66.67 LPP
10313 6 P6_ENGAGER_LPP Text Field $66.67 I
Question is that the field in field 6 displays the value $66.67. Why not 66.67?
On Page 6 a user can press the Update_lpp button and Invalid Number Error Page pops up?
Is there a way to hold in the session state the values only while formatting on the screen is $'
Thanks

Thanks. I did an "on submit and before computation" process that did a SQL replace on the page item. The DML process then successfully inserted the value into the database.
Alex.

Session State Protection Violation error

I am developing my first Apex application. I have this page which has been running fine until I made some changes. The error I get is the following:
-----Error message:
Session state protection violation. This may be caused by manual alteration of a URL containing a checksum or by using a link with an incorrect or missing checksum. If you are unsure what caused this error, please contact the application administrator for assistance.
--End of error message.
This happens Whenever the page is submitted for process, e.g. when I select from a "LOV with Submit" item or when I click the "Save Changes" button. It is fine if the button redirects to another page. Using Debug, I saw that the error occurs right after "Fetch page attributes" and before "Fetch session state from database".
About the changes I made before this error first surfaced: nothing to do with session state protection and nothing I can think of that is related to session state protection. In fact, I did not specify any session state protection at any level at this stage. That is, all pages and items are unrestricted. I did add a javascript to the page which is invoked onChange of an item to update another item. I made the same changes (except for the Javascript) to another similar page which is still running fine.
I tried logging out of Apex (I am using OracleXE) and getting back on, the error still persists. I even shut down and restart the Apex database to no avail.
Can anyone point me to where it might be the cause of this problem? Thank your help and/or suggestions in advance.
Message was edited by:
muighi

Scott - I should have posted this question sooner! I wasted a whole day trying to figure this out. Thanks a lot, Scott. By the way, where can I find any documented known bugs in Apex?
--Candy

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