I have a form page and all field is required when press save the below message appear
How i can change this message to custom message "please fill all required fields " , and how i can clear error when enter value (when value change to not null).
I can't see images at the moment.
However, one option might be to create your own validation which returns error text. Something like
if :P1_NAME is null then
return ('Name must be entered');
end if;
Messages are automatically cleared once you submit the page and there are no errors left.
I am not sure if you can change system messages but you can add custom error messages with javascript if a change happens in any item.
Add a change event to the item that runs javascript and use the following code:
var item = apex.item('P1_ITEM').getValue();
if(item == null) {
//First clear the errors
apex.message.clearErrors();
// Now show new errors
apex.message.showErrors([
{
type: "error",
location: [ "page", "inline" ],
pageItem: "P1_ITEM",
message: "Name is required!",
unsafe: false
},
{
type: "error",
location: "page",
message: "Page error has occurred!",
unsafe: false
}
]);
}
However, this will not stop the user from submitting, it only allows you to better display the messages, so you must add the corresponding validations after submit.
If you want to remove the system error message from the required items, you can disable the option of Value Required on item and add a custom validation as they told you in the other response.
If you want to explore all the apex.message options better, I recommend this documentation:
https://docs.oracle.com/database/apex-5.1/AEAPI/apex-message-namespace.htm#AEAPI-GUID-D15040D1-6B1A-4267-8DF7-B645ED1FDA46
More documentation for apex.item:
https://docs.oracle.com/cd/E71588_01/AEAPI/apex-item.htm#AEAPI29448
There are some ways for how to do such things.
Firstly you have the custom Validations you can make, these are awesome and you should really try to use them if possible.
Then there is also the Error message on the saving procedure, but this just throws a custom message on procedure fail so I never use it.
What you appear to be seeing there is that you got an error message and didnt change the fields associated with the error.
If the save procedure is custom, you can also put in an EXCEPTION block before the END, and catch errors there and throw out a custom error with a custom error message.
Another thing I really like is to actually rename some common errors so I dont have to catch them all individually. Say clients may often times try to save identical data, thus breaking the PK. Oracle will throw an error, but the message is good for the developer, but less understandable for the client whom I always assume is a 3 year old kid who can barely read and will cry over everything. So I make an error handling function, add it to apex, and so when the error occurs, it throws a nice message informing the client that they have tried to add some data that already exists.
So, an error handling function associated with APEX, to rename some normal errors.
Good luck
I'm trying to get some data from Application.Current.Properties storage. Unfortunately, any time I want to use this Dictionary, I see this error:
An exception of type 'System.AggregateException' occurred in mscorlib.ni.dll but was not handled in user code
Additional information: One or more errors occurred.
And in details I found this:
{"Error in line 1 position 206. Element 'http://schemas.microsoft.com/2003/10/Serialization/Arrays:Value' contains data of the 'http://schemas.microsoft.com/2003/10/Serialization/Arrays:ArrayOfstring' data contract. The deserializer has no knowledge of any type that maps to this contract. Add the type corresponding to 'ArrayOfstring' to the list of known types - for example, by using the KnownTypeAttribute attribute or by adding it to the list of known types passed to DataContractSerializer."}
It seems like I tried to save some non-string data to Application.Current.Properties. Unfortunately I can't run .Clear() method to erease all data, bacause I receive this error any time I'm trying to access this property.
What should I do to make it work?
Well, as its name suggests AggregateException, is just a container for one or more exceptions which may be thrown when using PLINQ or TPL.
As such exceptions may be thrown on different threads and may also occur concurrently, the system automatically catches and rethrows them within an AggregateException wrapper to ensure that they all get reported in one place. The exceptions themselves are exposed via the InnerExceptions property.
You can catch an AggregateException and check which exceptions it actually contains with code such as the following:
try
{
// perform some parallel operation
}
catch (AggregateException aex)
{
string messages = "";
foreach(Exception ex in aex.InnerExceptions)
{
messages += ex.Message + "\r\n";
}
MessageBox.Show(messages);
}
So I suggest you do this to see what is causing the problem
Please, remove your app from your device, Settings - Applications- Uninstall, this works for me. The Auth Object was crash in debug mode.Clean and Rebuild can be Helpfull to.
In my project, I have this config in struts.xml
<action name="searchTracker" class="searchAction" method="searchTracker">
<result name="success">/jsp/searchTracker.jsp</result>
<result name="error">/jsp/searchTracker.jsp</result>
</action>
And here is my action method in searchAction Action
public String searchTracker(){
this.clearErrorsAndMessages();
List<File> queryResults = fileManager.retrievequeryResults(patchNumBySearch); // patchNumBySearchis input from the page
if(queryResults == null){
this.setTrackers(null);
addActionError("This patch number doesn't exist. Please choose another one !");
return ERROR;
}
List<Tracker> trackers = commonUtils.convertToTrackers(queryResults);
this.setTrackers(trackers);
}
return SUCCESS;
}
if I input wrong param and the queryResult is returned as NULL, the page searchTracker.jsp can correctly show error message in itself as I wish, but after this, I enter correct param, it show error directly below
"Errors on action com.harris.northstar.dbadesk.action.SearchTrackerAction#9bee3a, returning result name 'input'"
I just compared debug log in two different case, and found that only one line difference
"converter is null for property patchNumBySearch. Mapping size: 0"
if this line exists, it will go into my action, if not, it will go to the error asking for input result. What is the line meaning?
and didn't get into the action class yet. I know the reason is that it violate some default validation interceptor and throw this exception, but I can't find anything wrong with this request with correct param. If I enter correct param firstly, it can get queryResult and goes to Success result without problem. The only different is timing.
Do I have to add input result in the configuration xml? I met some project before, and they only has success and error result, no input result at all, why it doesn't works? Something is wrong with my struts.xml?
And I don't want to create my own interceptor by disabling struts default validation interceptor
I just found a way to walk around it. just delete error result in configuration file, only keep success result, and remove AccionErrors in method searchAction, so user wont' get any warning message for their query request, just show nothing on the page, but this way is secondary option. I still want to show up the error message by solving this problem.
The input result would be called when a validation error occurs before transferring the control to the action method. In this case, I suggest that, you define a result type input to the initial jsp and try printing the fielderrors and actionerros using <s:fielderror /> and <s:actionerror /> respectively. This will give you a better outlook and you will come to know how to handle this in the next step depending on the error type.
I have a jqgrid which works fine. However there is a constraint in my database and I need to provide more meaningful validation method when adding.
The problem is when I submit the dialog shows the error: error Status: 'error'. Error code: 500
I would much prefer it to show the actual error caused by the exception thrown on save:
Violation of UNIQUE KEY constraint 'UKC_InvoiceId_ActivityId'. Cannot insert duplicate key in object 'dbo.InvoiceLine'. The duplicate key value is (11, 1). The statement has been terminated.
Can anybody tell me how to achieve this?
If you use ASP.NET then you can use try {...} catch (SqlException ex) {...} block over the code which implement the row insertion. You can analyse ex.Procedure, ex.Server, ex.LineNumber, ex.Message values inside of the SqlException and generate (throw) another exception with more readable message. You can use in the error message the texts typed by the user and explain which data the user have to modify to solve the problem.
When validating data, I've gotten into a habit of doing the following:
Note: I don't really have individual booleans for each check. This is just for the example.
Another Note: any error handling during the tests are done properly. The ONLY exceptions thrown in the try-catch are my own.
try {
if (validCheckOne = false) {
throw new Exception("Check one is bad");
}
if (validCheckTwo = false) {
throw new Exception("Failed because of check2");
}
if(validCheckTen = false) {
throw new Exception("Yet another failure on your part: check10.");
}
} catch(Exception e) {
MessageBox.Show("Your stupid data is wrong! See for yourself: " + e.Message);
}
Is this bad practice? Does throwing Exceptions slow the program's execution or is inadvisable?
Personally I like throwing Exceptions for business rule validation (not so much for user input validation) because it forces the problem to be handled upstream. If my business objects returned some kind of validation result, it could be ignored by the caller. Call me a cowboy if you wish :)
Everyone here is repeating the phrase "exceptions are for exceptional circumstances", but that really doesn't give any understanding of why its bad to use them for unexceptional circumstances. I need more than that. Is the performance hit of throwing exceptions really that bad? Are there any benchmarks available?
I'm going to repeat the mantra here: throwing exceptions should be done in exceptional circumstances. Invalid entered data is really not that exceptional.
I support MusiGenesis's answer.
Additionally...
The performance of throwing an exception is a thousand instructions. It's nothing compared to end-user time, but in inner code it is slow.
An additional problem is that, using Exceptions, your validation is limited to reporting the first failure (and you will have to do it all again next time to find the next failure).
In addition to the oft-repeated statement that "exceptions are for exceptional circumstances", here's an additionally clarifying rule I've come to like:
If the user caused it, it's not exceptional.
Exceptions are for system-side things (servers going down, resources being unavailable), not for the user doing odd things, because all users do odd things.
It depends - if you are expecting the data to be there and NOT having the data is unexpected, then throwing an exception is OK. Throwing an exception is very expensive (slow) but is the best way to handle unexpected circumstances.
In the title you call it "validating" data. That can happen on several levels. In (near) the GUI where you are checking user entered data, you should be expecting errors and have ways to report the errors back. Exceptions are inappropriate in this case.
But Data Validation can also happen at other boundaries, say between business-rule classes. There, errors in the data are uncommon and unexpected. You should throw when you detect one.
So maybe in some languages exception throwing and catching is "costly" but in other languages, throwing and catching exceptions is exactly what's called for.
In Smalltalk, for example, one could quickly build a multi-tiered exception catching solution. The validation pass could collect up any number of exceptions representing EVERYTHING that's wrong with a particular input data set. Then it would throw them ALL up to a higher-level catcher, responsible for formatting up a human-readable explanation of, again, EVERYTHING that was wrong with the input. In turn it would throw a single exception further up the chain, along with that formatted explanation.
So... I guess what I'm saying is, exceptions are only bad to throw if you've got no exception handling architecture supporting catching them and doing reasonable things with them, and all your catcher is going to do is EXIT or do something else equally inappropriate.
This is bad behavior. Exceptions are for Exceptional conditions. They take resources to generate the stack etc. Exceptions should not be used to dictate process flow.
In general it is inadvisable to use Exceptions to implement conditional flow. It would be better to do something like this
error = false;
while(true) {
if(validCheckOne == false) {
msg = "Check one is bad";
error = true;
break;
}
if(validCheckTwo == false) {
msg = "Check two is bad";
error = true;
break;
}
...
break;
}
if (error) {
..
}
You should throw an exception when there is a situation you can't do nothing about it. Higher layers of software would have a chance to catch the exception and do something about it - even if that is simply crashing the application.
I would suggest that using exceptions as described in the question (for flow control within a function) is wrong not usually the best idea. I'd go further and saying validation throwing exceptions isn't the best approach; instead return a Boolean and store a list of validation error messages that can be accessed. An accompanying save method could/should throw an exception if it is called on an invalid object.
Thus if validate fails validation error messages can be displayed to the user (logged, returned. whatever). If validation passes then you can call save.
If you call save on an invalid object then get get an appropriate exception.
Another potential problem with your example code (depending on requirements of course) is it only throws the first validation error that occurs. Imagine this from a users POV:
Click save
Get an error message
Correct error
Click save again
Get a different error message. Annoying.
As a user I'd prefer to get all validation errors returned at once so I can correct them all before trying again.
I generally agree with the "exceptions should be exceptional" rule, but I might make an exception (ha!) for Python, where it can be both efficient and considered good practice to use try ... except to control flow.
See Using Exceptions For Other Purposes, for example.
This question is still interesting, mainly because of the answers.
When it comes to exception, there is a lot of arguments involved. We can defend a point to any direction we want to, from performance to exception philosophy. And they all sounds right to me.
But sometimes we have to stick to a direction. In this case, I think it's the validation itself.
When we want to validate something we also want to know (to log, or to show the user) whats wrong when the parameter is invalid. Even thought there are layers of validation such as Business Validation mixed with User Input validations.
For instance, when dealing with user input, a lot of weird cases can happen. A pasted data from a website full of hidden char (\t \n etc), typos, and a really huge kinds of cases that a specific exception could allow further analysis or message to the uses much more precisely than a simple "false" return.
When you go to the grocery and ask the seller if he's got cheese, and the seller replies with no, would that be an unexpected or exceptional response?
What about if you do the same but the seller just looks at you and does not respond!
Another example, you are talking to your friend and ask if there is something wrong, you may get 2 responses:
They tell you that they are sad because of something.
Or they just look at you and say nothing, turn their back and walk away and you are sure that this means you're in deep trouble :)
Same way with exceptions, unexpected behavior is an exception, but an invalid but expected response should not - IMHO - throw exceptions.
I often write similar code for validation, especially in express.js, and similar request/response loop style applications. When something is invalid, I throw a ValidationError, it's caught by the top level error handler, which knows to send a 422 response with the additional information that's attached to the ValidationError.
It's a very convenient way to handle validation. You don't have to pass around an error object (potentially up through a dozen stack frames, in some cases). And it's a simple and consistent way to trigger an invalid input response. I haven't experienced any serious problems with this approach.
I've thought about the "don't use exceptions for flow control" maxim in relation to this practice, and decided the benefits outweigh any disadvantages. I would say if you understand the reasoning behind "don't use exceptions for flow control", but you determine that it's a good idea anyway in a certain case, then go ahead and do it. We don't need to be too dogmatic about these things.
Throwing exceptions is relatively slow, but that will only matter if you're doing it repeatedly in a loop.
It really only matters if your data validation is in a tight loop. For most cases, it doesn't matter what you choose as long as you are consistent in your code.
If you have a lot of code that looks like your sample above then you might want to clean it up by introducing a helper method to throw...
private void throwIf( bool condition, String message )
{
if( condition )
throw new ApplicationException( message );
}
(also, doing this will help zero in on errors such as "validCheckOne = false" versus "validCheckOne == false" :)
Well, i know it's an old question. But i'll let my opinion here for the googler's who falled here like me:
If you are using a language with a bad try/catch support AVOID
THROWING exceptions for data validation;
DO NOT THROW a exception that will not be handled by the caller or
alserwhere;
DO NOT THROW a exception if you need to validate the rest of the received data;
You can THROW a exception in cases where the code block cannot continue
without the invalid data; And if you do not interrupt the process you
can get a unhandled exception;
An example:
/*
* Here it's a common problem i have: Someone pass a list of products i need to
* retrieve from the database and update some information;
*/
//This is a class to represent the product
function Product(id, name, price) {
this.id = id;
this.name = name;
this.price = price;
}
//This is an example function to retrieve the product from the database
function findProductInDatabase(productId) {
//If the product exists on the database, the function will return it
if (productId == 12) {
var product = new Product(12, "Book", 20.5);
return product;
}
//If the product do not exists, it will return null
return null;
}
//This is a function that will receive the productID and will update the received parameters
function updateProduct(productId, newProductName, newProductPrice) {
var productFromDatabase = null;
var errorMessage = "";
//Retrieve the product
productFromDatabase = findProductInDatabase(productId);
//If the product do not exist, i need to interrupt de method imediatily and alert the caller
if (!productFromDatabase) {
throw "Product not found";
}
//Validate the other parameters, but in this case i can validate all the parameters
if (newProductPrice < 10) {
errorMessage += "the price is too low";
}
if (newProductName.includes("<")) {
//If already has a error message in the variable i append " and " to the message make sense
if (errorMessage) {
errorMessage += " and ";
}
errorMessage += "the new name has invalid characters";
}
if (errorMessage) {
//if theres any error, i will throw a exception with the messages
throw errorMessage;
}
}
//This parte is where the method id called;
try {
updateProduct(9, "Book", 10.5);
} catch (exception) {
console.log("Case 1: " + exception);
}
try {
updateProduct(12, "<Book", 9);
} catch (exception) {
console.log("Case 2: " + exception);
}
In test, sure, but in a live environment, you'd hope they're never raised.
You'd hope to refactor your code to the extent that all data into your system are validated at source, and either the user, or the system that generated the input to your system, is notified of the issue.
Exceptions should occur if you've missed something and should be a fallback that is handled gracefully.
You could store anything that's causing these exceptions separately, so that they don't make it into your system without being checked over first.
You don't want, e.g. an invalid value that falls outside a range of values to skew your results.