I am in reference to the following method from BindingResult:
BindingResult.html#resolveMessageCodes(java.lang.String, java.lang.String)
I am trying to figure out the difference between an error code and a message code. Can someone please provide an example, especially one that would illustrate why there could be several message codes for a given error code?
Because web applications are internationalized, when you reject an object and want to have a message displayed for it, you don't use a hardcoded text because that will show the same no matter the language.
Instead, you specify an error code that later server as a key to retrieving the proper message from the bundles (and now the error code is a message code from the point of view of the method that must find the proper message text).
Your error code resolves to more message codes because Spring (based on the implementation) adds some additional ones for you. Here is a snippet from the Spring documentation:
[...] What error codes it registers is determined by the MessageCodesResolver that is used. By default, the DefaultMessageCodesResolver is used, which for example not only registers a message with the code you gave, but also messages that include the field name you passed to the reject method. So in case you reject a field using rejectValue("age", "too.darn.old"), apart from the too.darn.old code, Spring will also register too.darn.old.age and too.darn.old.age.int (so the first will include the field name and the second will include the type of the field); this is done as a convenience to aid developers in targeting error messages and suchlike. [...]
The last statement is the reason there are more message codes, to have control on the message that is displayed to the user, from a generic one (e.g. "Value required") to a more specific one given the context (e.g. "A value is required for field XXX").
The javadoc for DefaultMessageCodesResolver explains it further and gives an example:
For example, in case of code "typeMismatch", object name "user", field "age":
try "typeMismatch.user.age"
try "typeMismatch.age"
try "typeMismatch.int"
try "typeMismatch"
This resolution algorithm thus can be leveraged for example to show specific messages for binding errors like "required" and "typeMismatch":
at the object + field level ("age" field, but only on "user");
at the field level (all "age" fields, no matter which object name);
or at the general level (all fields, on any object).
Related
I have an array of possible i18n message codes. Lets call it codes. Let's assume it contains values
[most.specific, specific, default]
Let's assume the messages.properties contains messages for specific and default, but not for most.specific.
I would be happy to be able to write in my Thymeleaf template something like
#{${codes}}
to get a message for specific code (since it is the first one that is defined).
I need Thymeleaf to resolve the first available message code that is defined in messages file into a string, ignoring the other message codes.
How to do this concisely?
I'm trying to understand the plug-in sample from here.
There's this condition:
// The InputParameters collection contains all the data passed in the message request.
if (context.InputParameters.Contains("Target") &&
context.InputParameters["Target"] is Entity)
Speaking generally, not just with regard to this sample, on what prior knowledge should I base my decision to access a specific property? How could I have known to test whether the InputParameters contains a "Target" key (I assume I'm not supposed to guess it)?
And on what basis could I have known to ask whether the "Target" mapped value is of Entity type, and not some other type?
I found this post from 2 years ago, and I've found this webpage, saying (emphasis is mine):
Within a plugin, the values in context.InputParameters and
context.OutputParameters depend on the message and the stage that you
register the plugin on. For example, "Target" is present in
InputParameters for the Create and Update messages, but not the
SetState message. Also, OutputParameters only exist in a Post stage,
and not in a Pre stage. There is no single source of documentation
that provides the complete set of InputParameters and OutputParameters
by message and stage.
From my searchings, a single source still doesn't exist, but maybe the possible values can be found using the Dynamics Online platform, somewhere deep down the Settings menu, maybe? Any source would be great.
I know this is an "old" question that already has been answered, but I think this can be helpful. I've built a small web page that contains all the messages with all the Input/Output parameters. You can access it from here:
The best practice for doing this is to use a strongly typed approach. If, for example, you want to know which propertes are available on a CreateRequest, you would do:
var createReq = new CreateRequest() { Parameters = context.InputParameters };
createReq.Target; // Has type Entity
Take a look at the full blog post explaining this approach: Tip: Proper handling of Plugin InputParameters
Original answer:
It depends on which request we are talking about. See Understand the data context passed to a plug-in on MSDN.
As an example, take a look at CreateRequest. One property of
CreateRequest is named Target, which is of type Entity. This is the
entity currently being operated upon by the platform. To access the
data of the entity you would use the name “Target” as the key in the
input parameter collection. You also need to cast the returned
instance.
Note that not all requests contain a Target property that is of type
Entity, so you have to look at each request or response. For example,
DeleteRequest has a Target property, but its type is EntityReference.
In summary: Look at the actual request, e.g the CreateRequest.
In 2011 someone actually generated typed properties based on the message type. Kind of neat: https://xrmpalmer.wordpress.com/2013/05/27/crm2011-plugin-inputparameter-and-outputparameter-helper/
It would show you want parameters are possible per message.
I'm trying to find a good way to do field validation in a WebObjects app. If I have a text field and I tie a number formatter to it, it seems that the default behavior is to parse out the number IF the user enters in a valid number, or, if the user enters an invalid number, it seems to just ignore the value entered by the user. I can't do the validation in a save method or an action method because WO will have already ignored the non-number input by the time it reaches the action method. Is there a standard/recommended way, in a WebObjects app, of validating user input such that the user can be alerted of invalid input, rather than just ignoring the invalid input?
This page: http://en.wikibooks.org/wiki/WebObjects/EOF/Using_EOF/Validation claims that WO and EOF have "an incredible array of validation mechanisms" and even hints that there is a built-in way to prevent the user from entering inappropriate data, but I haven't been able to find any documentation or examples of how to do that (if there is, in fact, a built-in way). Coming up with a custom javascript validator to prevent inappropriate data seems like it would be a nightmare - finding a way to make the JS recognize and handle all of the same edge cases that the backend formatters/parsers handle. It would be nice if WO really did have a built-in way to propagate the formatter edge cases over to JS validation.
The above link also says there is a validationFailedWithException method in WOComponent that gets called "when an EO or formatter failed validation during an assignment", but how can I make a formatter fail validation in the non-number example case above? I've tried having the formatter throw an exception in the parse method if a non-number is entered, but that exception doesn't get passed to the validationFailedWithException method. Does anyone know how I can trigger an exception in a formatter that will trigger a call to validationFailedWithException()? And is that even the best/recommended way? Does anyone know of a better way?
I'm pretty sure, that validationFailedWithException is getting called for every formatting error. You should receive there an NSValidationException that wraps a ParseException. The method is usually called on the component containing the binding. It may get skipped on caret (^) bindings.
All the standard number formatter already throw a ParseException (see Format.parse(String)).
The validation handling in WebObjects can get quite complex, it really depends on your needs. But it was designed without JavaScript or Ajax in mind. Newer approaches in Wonder may incorporate the client side, but I have no experience with it.
The normal validation sequence is:
if needed convert the input into the target type with a formatter
call a validateAttributeName method on the target object, where AttributeName is the attribute name to receive the value
When something fails in this sequence validationFailedWithException is called.
While saving an enterprise object "validateFor..." is called on the objects. An exception at this point has to be caught in your action method.
So you have two points to handle validation errors. The "syntactical" errors have to be handled in validationFailedWithException. After this point you have valid inputs. You may manually further check those or greater object structures in your action method or in validateFor... (e.g. validateForSave).
I realize this is kind of "Stripes 101", but I guess I skipped that class.
I'd like to use the code that drops the "error" class into the field
tag class strings as the primary way to indicate missing required
fields. I'd then like to show a single error message along with any
other errors (like fields supplied with improper values).
Thus, the error info on the page might look like:
Sorry for the trouble, but:
1. Please supply values for all indicated required fields.
2. Please supply a numeric value for Zip Code.
etc.
I suppose I could go through the validation errors, look for ones for
fields where the value is empty, and make the assumption that those
were the required field errors. However, if I take those errors out
of the set, then I suspect that the page will no longer be able to
mark the erroneously-missing fields with the "error" class.
This seems like something likely to be pretty easy, but I can't find
any specific examples. Maybe I can do it all in the .jsp code; I'll start looking into that.
The DefaultActionBeanPropertyBinder adds an instance of ScopedLocalizableError with the default scope value of "validation.required" when a required field is missing.
So you coult probably write a tag similar to the stripes errors tag, but which collapes all the instances of ScopedLocalizableError having a default scope of "validation.required" to a single error message.
I am trying to do validations in struts 2 for my current project. I have to group my validation messages. For Eg: If there are 3 fields that are empty and there are 3 other fields whose format is not right, I need to get a msg like
"The following fields are required: field1, field2, field3
The format of the following fields are invalid: field4, field5, field6"
I tried providing a param to fieldError.
Eg:
< s : fielderror >
< s : param value="%{requiredstring}"/>
< / s : fielderror>
According to me this is like specifying "show all errors whose validator type is requiredstring". Please correct me if I am wrong.
But this will display the message "The following fields are required" each time for every field that is empty. I want it displayed only once.
Is there a way to do this cleanly in stuts2 using validation through xml? I donot want to do all the validations in a validate method.
Thanks
You are wrong; I have no idea why you thought that'd work, the docs don't imply that's possible.
Field errors are just that--errors for a specific field. If you need to group errors by arbitrary criteria, like the validation type, you'll need to implement that yourself.
There are a number of ways to do this, including writing a custom validation interceptor, providing validators that group errors in a different way, or simply gathering the appropriate messages in an action or validation method.
You could gather errors based on the message content, but IMO that would be brittle. If this is a cross-application issue, you're better off doing it a different way.
All that said, by presenting error messages in an order not necessarily reflective of the form, you're pushing more cognitive overhead onto the user: I don't want to see groups of messages telling me which fields share the same error, I want to see what's wrong with each field, in the same order the fields are presented on the form, preferably near the form field itself.