I have a wizard control and in one of the steps, I dynamically build a table. If I move forward to the next step and decide to return back to the step with the table, the table is destroyed and only the header row is there. I set up some test scenarios and the bottom line is that when you leave the step, the table is wiped out.
I have view state enabled and set to true. What am I doing wrong?
Problem solved....disable view state.
Related
We have a hierarchical watch app.
The root controller is a table of menu items. That list of items is controlled by a server. The data is retrieved and stored in core data. The menu is populated the first time going into the app.
But I want this table to stay current. My thought was to add code to willActivate to check if there was changes, and reload the table. In my reload logic I call the same function I called the first time, which sets the menuTable.setNumberOfRows and creates each row. Looking at what I'm putting in the logs, it is going through this logic with a different count of rows and new labels. But the app on the watch shows the table with the old data.
How can I get this table to reload with the new information?
I've had this problem too and as rmp says, it still seems to be a bug in watchOS 1.0.1. The problem appears when you try to reload your tableView after run willActivate() and nothing will happen.
In my case, I reload the tableView after receive a reply from a delegate and then I reload all the content just if it's necessary. To achieve this, I remove all rows from a NSIndexSet and load again.
if isNecessary {
self.table.removeRowsAtIndexes(NSIndexSet(indexesInRange: NSMakeRange(0, maxItems)))
isNecessary = false
}
I've tried a lot of tricks but none has worked for me:
Force to reload rows by table.setNumberOfRows(0, withRowType: "data")
Setting parameters to empty text before assign new values
One thing you could do is to hide tableView before removing rows, and avoid the remove animation.
It is a bug in WatchKit. Seems like Apple doesn't handle the repetitive interface object correctly.
The general principle here is: Only insert or remove necessary rows after a table is created. Do not reload the whole table like what we usually do in iOS. It just doesn't work (or trigger the bug).
So specifically, you have to:
Do this in willActivated method. This is correct.
If this is the first load, before the table is even created, do what you are now doing – load all table rows.
For all following times, don't reload the table, fetch the new data and check the desired number of rows.
Compare with the current number of rows in the table, insert to or remove from the bottom of the existing table.
Now simply re-assign the new data to all existing rows. Again, do not reload.
It should work if you follow the above steps.
I have found what works best given the current state of watchkit is to remove all rows then re-populate the table.
Try something like this:
- (void)loadTableData{
//clear the table
[mainTableView setNumberOfRows:0 withRowType:#"myTableRow"];
//set the row count again
[mainTableView setNumberOfRows:numberOfRows withRowType:#"myTableRow"];
//populate table
}
Its pretty simple. As Apple hasn't provided any method to reload the data.
You can still achieve that by simply populating the rows for the tableview.
Below is the sample code:
for index in 0..<tracksTableView.numberOfRows {
if let controller = tracksTableView.rowController(at: index) as? EditPlaylistRowController {
controller.playingTrackId = self.playingTrackID
controller.sharedTrack = trackItems[index]
}
}
Use it whenever you want to refresh the data.
NOTE:
You can still make some conditional statements inside the row controller class.
Happy to help :)
I'm having an issue binding the value of a page item to a declared variable in an anonymous PL/SQL block process.
The problem is that the page item (:P4550_REQUESTOR) is not populated with a value until a conditional is met. It appears that the PL/SQL block process is binding the variable to an empty value as soon as the page is loaded, despite the fact that the process does not fire until a specific button has been clicked.
Here is my code:
DECLARE
v_email_to app_user.email%type;
v_requestor VARCHAR2(15);
BEGIN
v_requestor := :P4550_REQUESTOR;
BEGIN
SELECT email INTO v_email_to
FROM app_user
WHERE userid = v_requestor;
END;
SEND_APEX_MAIL (
v_email_to,
'Your vacancy request has been rejected.'
|| chr(10)
|| 'Emailed to: ' || v_email_to
|| chr(10)
|| 'Requestor: ' || v_requestor,
'Vacancy Request Rejected'
);
END;
Does anyone have any thoughts on this?
The block works just fine if I hard code a value to v_requestor. If I try to get the value of P4550_REQUESTOR after the page has loaded, it is empty. After clicking the edit button, P4550_REQUESTOR is populated.
** **MORE DETAIL** **
P4550_REQUESTOR is a page item that resides within the Vacancy Request region which is only displayed when a conditional is met. Specifically, the conditional is an edit button associated with a table row that is created on page load. Clicking the edit button causes the details region to display, and the associated page items to be populated.
The page item values in the Vacancy Request region are populated via an Automated Row Fetch which fires After Header.
P4550_REQUESTOR has a Source Type of DB Column.
The process that fires the code above is set to fire On Submit - After Computations and Validations
If I log the value of P4550_REQUESTOR when the page loads, it shows null. If I log the value after clicking the edit button, I get the expected string value.
Process Flow Control in Oracle APEX
(This is actually useful to think about in other programming disciplines and environments.)
Problem Defined
The problem is that the page item (:P4550_REQUESTOR) is not populated with a value until a conditional is met. It appears that the PL/SQL block process is binding the variable to an empty value as soon as the page is loaded, despite the fact that the process does not fire until a specific button has been clicked.
The problem statement reworded in Apex terminology and presented in the form of an actual question:
There is a REPORT REGION on the page which contains the result of a direct reference to a data table/view. This report is managed by an Apex process called "Automated Fetch" and is initiated automatically by the loading of the page headers.
There is a FORM ITEM on a page which which is populated conditionally by a BUTTON ITEM selection made by the user. The BUTTON ITEM is part of the report results.
There are multiple button items. Each is associated with a value for each report record.
If the user does not select the BUTTON ITEM from the REPORT REGION, the FORM ITEM remains unassigned and contains a "null" value.
There is a defined PL/SQL block of code which is set to execute when a SUBMIT BUTTON item is pressed (also on the same page). Why does my code block (defined page process) run with a null value when it is triggered without first pressing a BUTTON ITEM from the REPORT REGION first?
Event Driven Program Design for Procedural Programmers
The answer is not obvious if you think under the paradigm of a procedural language. Without diving into a lecture on the topic, here's a visual layout of the problem space of the OP that I cooked up to illustrate how the problem can be made more obvious:
This is my Apex page design in implementation. It's generic enough to use as a template for other Apex designs. There are no flow arrows on this diagram because it's a stateful system. One thing causes another thing to happen and so on... but not always and not all at the same time.
Use Cases for Apex UI Page Designs
Try walking through a few use cases to understand how the elements broken down in the diagram operate together. Each user may take any number of click combinations and interactions, but there is a commonality:
They all enter the same initialized conditions on page load.
They all leave the page by: navigating elsewhere or through the SUBMIT button event.
Use Case #1
User chooses {MyPage:SQLReport:ThisButton} from one of the records in {MyPage:SQLReport}
According to {MyPage:SQLReport:ThisButton} #3, the value associated between the report record and the button item is passed to: {MyPage:HTML-Region:ThisItem}
The form item state has been updated and changed from the initial null value.
User selects {MyPage:HTML-Region:ThisSubmit} button to inform the system to continue on.
The submit button executes the defined PL/SQL procedure block: {MyPage:RunCodeBlock}
Use Case #2
User enters page and reviews results displayed in the {MyPage:SQLReport} region.
User decides no additional input is necessary and then selects the {MyPage:HTML-Region:ThisSubmit} button to inform the system to continue on.
(a note: the state of form item {MyPage:HTML-Region:ThisItem} has not been changed from the initial null value at this point... after the submit button has been selected)
The submit button executes the defined PL/SQL procedure block: {MyPage:RunCodeBlock}
Use Case #3
User chooses {MyPage:SQLReport:ThisButton} from one of the records in {MyPage:SQLReport}
According to {MyPage:SQLReport:ThisButton} #3, the value associated between the report record and the button item is passed to: {MyPage:HTML-Region:ThisItem}
The form item state has been updated and changed from the initial null value.
User chooses {MyPage:SQLReport:ThisButton} from a different selection from one of the records in {MyPage:SQLReport}.
According to {MyPage:SQLReport:ThisButton} #3, the value associated between the report record and the button item is passed to: {MyPage:HTML-Region:ThisItem}
The form item state has been updated and changed from the initial value stored in step (2).
User selects {MyPage:HTML-Region:ThisSubmit} button to inform the system to continue on.
The submit button executes the defined PL/SQL procedure block: {MyPage:RunCodeBlock}
The difference between each case should illustrate why the dependent value (ThisItem, or more specifically, page item P4550_REQUESTOR) is null in one use case vs. the other.
Building a Physical Implementation (An Apex Page)
The table I used is called STAR_EMPS. It is similar to the EMP table but has only three columns: ename, deptno and salary. Although it is not super important, this is the data set I used to populate STAR_EMPS:
I used a simple two-column table named STAR_EMPS_LOG for capturing the output of a successfully executed procedure call. You could accomplish the same with just one column, but I wanted a sequential id for tracking the order each event was recorded- for running multiple test cases. The procedure is one of several defined processes kept on this page:
contained in: {MyPage:RunCodeBlock} is below:
DECLARE
-- output from this procedure will be recorded in the star_emps_log
-- table. {MyPage:RunCodeBlock}
mycelebrity star_emps.ename%TYPE:= :P17_CELEBRITY_NAME;
mylogmessage star_emps_log.log_message%TYPE;
BEGIN
-- Conditional; changes message based on the value set for the
-- page item.
if mycelebrity is null then
mylogmessage:= 'No button was pressed on the previous page.';
else
mylogmessage:= 'The user selected: ' || mycelebrity ||
' from the report list.';
end if;
-- populate value from the page item.
INSERT INTO star_emps_log (log_message)
VALUES (mylogmessage);
commit;
END;
This is how the page layout was set up:
As in your example, I made a {MyPage:SQLReport} region with its supporting elements. The SQL Report represents a query directed at the source data table.
{MyPage:Form} has been renamed to {MyPage:HTML-Region}.
{MyPage:SQLReport} is defined by a SQL query, there is also a mock column to use as a place holder for placement of the "edit" buttons.
{MyPage:SQLReport:ThisButton} The button specifications are detailed through this:
The TWO Page processes: PROCESS and BRANCH need to be linked with the same settings referencing a BUTTON triggering Item.
User Interface Test Cases
Run through the three suggested scenarios to get started. Verify that the system is interpreting the requests correctly. This is what the page layout looks like:
The two processes on the system have a definition that wasn't mentioned in previous discussions may solve our original problem at hand:
Some Parting Thoughts
It is a good thing this turns out to be a trivial case once broken down. The diagramming method described here should scale to other Apex applications of varying complexity. There is considerable utility in stepping away from the code, locking down on terminology and trying to describe systems and processes without actual code. Please be sure to share any stories if this approach helps with your own Oracle Apex design challenges.
Onward!
The original, verbose answer seems to way overcomplicate the issue. The session state concepts manual covers this behaviour more succinctly.
Should P4550_REQUESTOR be a normal item created from a wizard, using :P4550_REQUESTOR will return a value in processes running post submit because the submit processes moves values in browser to session state.
If P4550_REQUESTOR is rendered conditionally, then it will always be null and I'm not sure what would happen if you tried to set it - probably depends how.
On a similar note, if you used &P4550_REQUESTOR. to parameterise the process, you would face the behaviour originally described (and made the code less secure)
Within AX 2009, I have, through compare and compile, added two new controls within a datagrid on a form, a Real edit and a combobox. I have compiled with no issues. The Allow Edit property is set to Yes on both controls.
However, on the form, if I edit one row, whether typing a new number with Real edit or combobox, and don't hit Save but hit the Down Arrow key, the data I typed on the previous records is duplicate in the next record and so on until I release the Down Arrow key, rather than just setting the focus on a new record.
The table where these fields were created doesn't exhibit this behavior. The focus simply moves to the next record and what was typed will not carry over to the next record. Only the form does this...
Has anyone seen this behavior before with AX forms?
You may have omitted to specify the data source on the grid itself?
Or if the new controls are based on Edit methods on the data source, have you got the data source parameter in the method signature?
see http://msdn.microsoft.com/en-us/library/aa637541(AX.10).aspx
I'm working on my first ever AIR application with flashbuilder - just so you know.
I've bound a mx:DataGrid component to a DataProvider which is a mx:HTTPService fetching an xml file with items. To keep the data up to data I'm polling the webservice on a given interval.
My problem is that I loose the currently selected item in my DataGrid when the data is updated. I've tried to save the DataGrid.selectedIndex and set when the data is updated, but I'm not sure when to do it?! The closest I've come is to restore the index when the updateComplete event of DataGrid is fired. This works, but the selection first fades away and then fades in - not updated soon enough.
So what is the best way to keep the selection? (only one selected item at a time)
And as a side question: is there a convenient way to only update the data when it has actually changed?
Thankful for any suggestions!
I'll start from the bottom, the only way to only update the data when it has changed is to pass a check on the data on the server side to see if data has changed and make that a call before the actual update. So in short, you make two calls, one to see if the data has changed, which is a server side query, and the next only if that returns true, which updates the data.
Alternatively, you can also get the update, and compare it to your current data, and only update the UI if that data is different, but I have a feeling you mean the former answer of only doing the update CALL at all, if the data has changed.
As for the other solution, after you've saved the selectedIndex, do this inside your updateComplete:
private function yourDataGridUpdateComplete(event:FlexEvent):void{
yourDataGrid.selectedIndex = yourIndex;
yourDataGrid.validateNow();
yourDataGrid.scrollToIndex(yourIndex);
}
The DG uses the UUID of the data items to determine whether the item should be still selected after a refresh. If the data items don't implement IUID they basically get random values created each time they are added to the DG.
If your data items implement the IUID and you use a consistent value (DB sequence number for example) the DG will "know" that after a refresh, the data item is the same one as before.
I have a web apllication with wizard control with 4 step index. Each having a dynamically editable grid which need to put only valid data & goto next.
In one step which have 2 columns which are not require to be editable because it has set its value from previous field by calculation, done with javascript.
But problem is that when we decalre these field as a enable false or read only mode then it works but can not able maintain state means its value goes off when we change the step index changed. (If that field are editable then it works ok.)
Also I tried it by use of label field but the same thing happen when the step changes label can not maintan its state (its value clears when step changes).
Please give me idea how to resolve this problem. Also each step has a dynamically created editable grid.
Thanks & Regards,
Girish
Well, if your javascript is doing the calculation from another field that is set by the user, then why couldn't you just redo that calculation on the server side when switching to the next step. I am assuming that the "value from previous field" is getting passed back to the server.
Another solution would be to have your javascript populate a hidden field too (in addition to the one viewable by the user). Then you just read that hidden field.