I have a couple of text fields that are filled from the database when the value of a select list changed.
I added another action to the list change dynamic action to execute PL/SQL code:
IF :P2_SELECT_LIST1 LIKE '%ABC%' AND :P2_NAME = 'WWW' THEN
:P2_NAME = NULL;
END IF;
Nothing happend on the page when I change the value of the select list, but the session value of P2_NAME gets cleared.
I also tried:
IF :P2_SELECT_LIST1 LIKE '%ABC%' AND :P2_NAME = 'WWW' THEN
:P2_NAME = '';
END IF;
But gotten the same result
In this dynamic action there are two fields next to your pl/sql code:
Items to submit: list the items here that you use in your pl/sql to get the values from session (if necessary, the values are usually already in session).
Items to return: list the items here that you need to refresh the value on the HTML page after some change in your pl/sql
I think this solves the problem.
Related
I am new to Oracle apex.
I have a page with a form that is used to enter data into a table.
For Example there is P_ID, P_NAME, P_ADD_USER, P_VERIFIED_USER, P_SECOND_ID items. I want to make P_SECOND_ID read only based on multiple conditions.
Condition is
IF P_ADD_USER <> :APP_USER AND P_SECOND_ID = ' ' THEN
'P_SECOND_ID should be available to Edit.
ELSE
P_SECOND_ID will be read only.
I tried to use Type = Item!=Value but it is allowing me to add only one condition so is there any option that i can use both conditions and make that ITEM read only.
Condition I'd suggest in such a case is a function that returns a Boolean - if it returns TRUE, something will happen; otherwise, it won't.
So, if you want to make P_SECOND_ID editable if conditions you mentioned are satisfied, then you'd
return not ( :P_ADD_USER <> :APP_USER
and :P_SECOND_ID = ' '
);
Though, did you really want to say :P_SECOND_ID = ' '? Is there a space character in it? Should that, perhaps, be :P_SECOND_ID IS NULL?
SQL Expression allows you to include multiple conditions. You might want to rephrase your requirement to make the item read only ( versus making it editable ) under certain conditions. If I get your requirement right, the condition to make P_SECOND_ID read only is when
:P_ADD_USER = :APP_USER OR :P_SECOND_ID is not NULL
You can use this expression directly in the SQL Expression.
I have an item on the page which I want to show/hide on page load based on the value of another item. If item2 is Yes, then show item1, or if item2 is No, then hide item1.
I know how to do that using dynamic action and javascript but I want to avoid using javascript. Is there a way to use APEX built-in functionality to do that? I know I can use Show action to hide an item, but I only need to show it if item2 is Yes. The APEX Show action does not have a condition
Also have the same issue with On Change event:
var result = document.getElementById("result");
var status = document.getElementById("status");
if (status.options[status.selectedIndex].text == "Completed") {
var r = confirm("Are you sure you want to set the status to Completed?");
if (r == true) {
apex.submit({request:'STATUS_CHANGE'})
}
} else {
result.value = "";
$x("P2_THE_DATE").value = "";
apex.submit({request:'STATUS_CHANGE'})
}
//set a value of a hidden field for status
apex.item("P2_STATUS").setValue(status.options[status.selectedIndex].text);
Is there a better, more efficient way to do this?
ITEM2 must get its value on load somehow, right? So, use the same code (that populates ITEM2) as a condition for ITEM1 and check whether its value is "Yes" (and display it) or "No" (so don't).
I prefer using a function that returns a Boolean to do so; something like
declare
l_item2 varcahr2(10);
begin
-- this is supposed to look like source for ITEM2
select ...
into l_item2
from ...
where ...;
return l_item2 = 'Yes';
end;
Isn't that a perfect use case to incorporate js - to have a dynamic behavior on a web page. Why would you want to avoid it? I'm just curious.
Anyway, you could however achieve similar behavior, provided the item2 is a Select List or Radio Group.
Set the 'Page Action on Selection' to Submit
Set the source used to 'Only when current values is NULL' - so the value gets stored in the session even after submitting the page.
Have the conditional display for item1 set as "ITEM is NOT NULL" and choose ITEM2 as the item.
If you follow these steps, the ITEM1 would show up after the selection of ITEM2.
I created form for customers, I need to do validate customer name like
1 - type the new name into item P1_CUST_NAME.
2 - after leaving this item go to database and check if this name already exist or not.
3 - display alert or message for the client.
4 - prevent the client from navigating a way from this item until he enter valid data.
Yes, you can create server side validation by using Dynamic Action and JavaScript function apex.server.process.
A basic example to demonstrate-
Create a page item e.g. P4_NAME in your page
Create a page process and select the execution point as "AJAX
CALLBACK".
In below code I am checking the P4_ITEM value, you can write your own logic to validate.
BEGIN
IF :P4_NAME = 'HIMANSHU'
THEN
HTP.prn ('SUCCESS');
ELSE
HTP.prn ('ERROR');
END IF;
END;
Now create a new dynamic action and select the Event as "LOSE FOCUS", Selection Type as "Item(s)" and in Item(s) select the item name.
Create a true action and select "execute JavaScript Code".
In code section, implement apex.server.process like below-
apex.server.process('validate_name',
{
pageItems : '#P4_NAME'
}
,
{
dataType : 'text', success : function(data)
{
if(data != 'SUCCESS')alert(data);
}
}
)
The first argument is the page process name(validate_name) which we have create earlier, second the data you want to submit to the process and third is options.
For more details on apex.server.process
It is done. Refresh your page and check. On validation failure you will get an alert.
You can customize your JS code further to display error messages in more fancy way instead of showing alert.
I am currently using this:
params["RPBla"].join(",")
as default parameter of a (stored procedure) dataset. This works fine and sends one or more selected values from the report parameter RPBla to a stored procedure, e.g.:
1,2,3
Unfortunately, this does not work if the user does not select any value. Any ideas what to do. Actuate BIRT should send NULL instead of for example 1,2,3.
What about testing the content in this default value expression, something like:
if (params["RPBla"].value==null){
null;
}else{
var list=params["RPBla"].join(",");
list.length>0 ? list : null;
}
Of course you could return anything you need instead of "null" here, for example returning a specific value warning the stored procedure that the filter should be disabled.
jqGrid has employee name and employee id columns.
If employee name has changed, server validate method should called to validate name. Current row columns should be updated from data returned by this method.
If employee id has changed, server validate method should called to validate id.
Current row columns should be updated from data returned by this method.
Preferably jqGrid should stay in edit mode so that user has possibility to continue changing, accept or reject changes.
How to implement this in inline and form editing?
I'm thinking about following possibilites:
Possibility 1.
Use editrules with custom validator like
editrules = new
{
custom = true,
custom_func = function(value, colname) { ??? }
},
Issues: How to get data from all columns, make sync or async call and update columns with this call results.
Possibility 2.
Require user to press Enter key to save row.
Issues: how to find which column was changed and pass this column number to server.
How to update current row data from server response.
Possibility 3.
using blur as described in Oleg great answer in
jqgrid change cell value and stay in edit mode
Issues: blur does not fire if data is entered and enter is pressed immediately. How to apply blur in this case ?
In summary server sice calculation/validation should be dones as follows:
If column in changed and focus moved out or enter is pressed in changed column to save, server side sync or if not possible then async method should be called. Changed column name and current edited row values like in edit method are passed as parameters to this method.
This method returns new values for edited row. current edited row values should be replaced with values returned by that method.
Update
Oleg answer assumes that primary key is modified. This factor is not important. Here is new version of question without primary keys and other updates:
jqGrid has product barcode and product name columns.
If product name has changed, server validate method should called to validate name. Current row columns should be updated from data returned by this method.
If product barcode has changed, server validate method should called to validate product barcode.
Current row columns should be updated from data returned by this method.
jqGrid should stay in edit mode so that user has possibility to continue changing, accept or reject changes.
How to implement this in inline and form editing?
I'm thinking about following possibilites:
Possibility 1.
Use editrules with custom validator like
editrules = new
{
custom = true,
custom_func = function(value, colname) { ??? }
},
Issue: custom_func does not fire if input element loses focus. It is called before save for all elements. So it cannot used.
Possibility 2.
Require user to press Enter key to save row.
Issues: how to find which column was changed and pass this column number to server.
Save method should known column (name or barcode change order) and fill different columns. This looks not reasonable.
Possibility 3.
using blur:
colModel: [{"label":"ProductCode","name":"ProductCode","editoptions":{
"dataEvents":[
{"type":"focus","fn":function(e) { ischanged=false}},
{"type":"change","fn":function(e) {ischanged=true}},
{"type":"keydown","fn":function(e) {ischanged=true }},
{"type":"blur","fn":function(e) { if(ischanged) validate(e)} }
]},
To implement validate I found code from Oleg great answer in
jqgrid change cell value and stay in edit mode
Summary of requirement:
If column in changed and focus moved out or enter is pressed in changed column to save, server side sync or if not possible then async method should be called. Changed column name and current edited row values like in edit method are passed as parameters to this method.
This method returns new values for edited row. current edited row values should be replaced with values returned by that method.
Update2
This question is not about concurrency. This is single user and jqGrid issue. Updating means that single user changes product name or barcode and server shoudl provide additonal data (product id and/or name/barcode) is responce of this.
Update 4
I tried code below.
If user enters new code and presses Enter without moving to other row, blur does not occur and validation is not called.
How to dedect in jqGrid save method if cell is dirty or other idea how to force this code to run if enter is pressed to end edit without losing focus from changed foreign key cell ?
function validate(elem, column) {
ischanged = false;
var i, form, row;
var postData = { _column: column };
var colModel = $("#grid").jqGrid('getGridParam', 'colModel');
var formEdit = $(elem).is('.FormElement');
// todo: use jQuery serialize() ???
if (formEdit) {
form = $(elem).closest('form.FormGrid');
postData._rowid = $("#grid").jqGrid('getGridParam', 'selrow');
for (i = 0; i < colModel.length; i++)
eval('postData.' + colModel[i].name + '="' + $('#' + colModel[i].name + '.FormElement', form[0]).val() + '";');
}
else {
row = $(elem).closest('tr.jqgrow');
postData._rowid = row.attr('id');
for (i = 1; i < colModel.length; i++)
eval('postData.' + colModel[i].name + '="' + $('#' + postData._rowid + '_' + colModel[i].name).val() + '";');
}
$.ajax('Grid/Validate', {
data: postData,
async: false,
type: 'POST',
success: function (data, textStatus, jqXHR) {
for (i = 0; i < data.length; i++) {
if (formEdit)
$('#' + data[i].name + '.FormElement', form[0]).val(data[i].value);
else
$('#' + postData._rowid + '_' + data[i].name).val(data[i].value);
}
}
});
}
colModel is defined as:
{"name":"ProductBarCode",
"editoptions": {"dataEvents":
[{"type":"focus","fn":function(e) {ischanged=false}
},
{"type":"change","fn":function(e) {ischanged=true},
{"type":"keydown","fn":function(e) {if(realchangekey()) ischanged=true}
},{"type":"blur","fn":function(e) { if(ischanged) { validate( e.target,ProductBarCode')}}
}]},"editable":true}
It's one from the problems which is much easier to avoid as to eliminate. I have to remind you about my advises (in the comments to the answer) to use immutable primary key, so that is, will be never changed. The record of the database table can be destroyed, but no new record should have the id of ever deleted record.
On any concurrency control implementation it is important that the server will be first able to detect the concurrency problem. It can be that two (or more) users of your web application read the same information like the information about the employee. The information can be displayed in jqGrids for example. If you allow to change the employee id, than the first problem would be to detect concurrency error. Let us one user will change the employee id and another user will try to modify the same employee based on the previous loaded information. After the user submit the midification, the server application will just receive the "edit" request but will not find the corresponding record in the database. The server will have to sent error response without any detail. So the errorfunc of the editRow or the event handler errorTextFormat of the editGridRow should trigger "reloadGrid" reload the whole grid contain.
If you allow to edit the primary key, then I can imagine more dangerous situation as described before. It can be that another user not only change the id of the current editing row to another value, but one could change the id of one more record so, that its new id will be the same as the current editing id. In the case the request to save the row will overwrite another record.
To prevent such problems and to simplify the optimistic concurrency control one can add an additional column which represent any form of the timestamp in every table of the database which could be modified. I personally use Microsoft SQL Server and add I used to add the non-nullable column of the type rowversion (the same as the type timestamp in the previous version of the SQL Server). The value of the rowversion will be send to the jqGrid together with the data. The modification request which will be send to the server will contain the rowversion. If any data will be save in the database the corresponding value in the corresponding rowversion column will be automatically modified by the SQL database. In the way the server can very easy detect concurrency errors with the following code
CREATE PROCEDURE dbo.spEmployeesUpdate
-- #originalRowUpdateTimeStamp used for optimistic concurrency mechanism
-- it is the value which correspond the data used by the user as the source
#Id int,
#EmployeeName varchar(100),
#originalRowUpdateTimeStamp rowversion,
#NewRowUpdateTimeStamp rowversion OUTPUT
AS
BEGIN
-- SET NOCOUNT ON added to prevent extra result sets from
-- interfering with SELECT statements.
-- ExecuteNonQuery() returns -1, but it is not an error
-- one should test #NewRowUpdateTimeStamp for DBNull
SET NOCOUNT ON;
UPDATE dbo.Employees
SET Name = #EmployeeName
WHERE Id=#Id AND RowUpdateTimeStamp=#originalRowUpdateTimeStamp;
-- get the new value of the RowUpdateTimeStamp (rowversion)
-- if the previous update took place
SET #NewRowUpdateTimeStamp = (SELECT RowUpdateTimeStamp
FROM dbo.Employees
WHERE ##ROWCOUNT > 0 AND Id=#Id)
END
You can verify in the code of the server application that the output parameter #NewRowUpdateTimeStamp will be set by the stored procedure dbo.spEmployeesUpdate. If it's not set the server application can throw DBConcurrencyException exception.
So in my opinion you should make modifications in the database and the servers application code to implement optimistic concurrency control. After that the server code should return response with HTTP error code in case of concurrency error. The errorfunc of the editRow or the event handler errorTextFormat of the editGridRow should reload the new values of the currently modified row. You can use either the more complex way or just reload the grid and continue the modification of the current row. In case of unchanged rowid you can easy find the new loaded row and to start it's editing after the grid reloading.
In the existing database you can use
ALTER TABLE dbo.Employees ADD NewId int IDENTITY NOT NULL
ALTER TABLE dbo.Employees ADD RowUpdateTimeStamp rowversion NOT NULL
ALTER TABLE dbo.Employees ADD CONSTRAINT UC_Employees_NewId UNIQUE NONCLUSTERED (NewId)
GO
Then you can use NewId instead of the id in the jqGrid or in any other place which you need. The NewId can coexist with your current primary key till you update other parts of your application to use more effective NewId.
UPDATED: I don't think that one really need to implement any complex error correction for the concurrency error. In the projects at my customers the data which are need be edited can not contain any long texts. So the simple message, which describe the reason why the current modifications could not be saved, is enough. The user can manually reload the full grid and verify the current contain of the row which he edited. One should not forget that any complex procedures can bring additional errors in the project, the implementation is complex, it extend the development budget and mostly the additional investment could never paid off.
If you do need implement automated refresh of the editing row I would never implement the cell validation in "on blur" event for example. Instead of that one can verify inside of errorfunc of the editRow or inside of the errorTextFormat event handler of the editGridRow that the server returns the concurrency error. In case of the concurrency error one can save the id of the current editing row in a variable which could be accessed inside of the loadComplete event handle. Then, after displaying of the error message, one can just reload the grid with respect of $('#list').trigger('reloadGrid',[{current:true}]) (see here). Inside of loadComplete event handle one can verify whether the variable of the aborted editing row is set. In the case one can call editRow or editGridRow and continue the editing of the string. I think that when the current row are changed another rows of the page could be also be changed. So reloading of the current page is better as reloading of the data only one current cell or one row of the grid.