I am trying to deserialize an Xml file content into a specific object. Everything runs fine but when I include empty tag of type date or time in my xml(having xsd that describes my xml structure) the deserialization fails. What can I do to make deserialization working when empty date tags are appear?
Thanks
Pan
A DateTime cannot be empty - instead try using the DateTime.Min value.
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I'm using Authorize.net API and they require card expiration field to be formated as "yyyy-mm". We did that with this simple line of code:
expirationDate = model.Year.ToString("D4") & "-" & model.Month.ToString("D2")
and this absolutelly worked. I still have cards stored in the system that were saved using this method! But today I was testing something completelly unrelated, and wanted to add another card, and bam, this code exploded with this exception:
System.InvalidCastException: 'Conversion from string "D4" to type 'Integer' is not valid.'
Inner exception to that one is:
Input string was not in a correct format.
This just... doesn't make sense to me. Why in the world is it trying to convert format specifier (D4) into an integer? What input string? What in the world changed in two days?
The problem is that your are using a Nullable(Of Integer). This is a different structure that does not support the overloads of the ToString method a normal Integer has.
You can view the overloads of the Nullable structure here.
I suggest you use the GetValueOrDefault() method to get the proper Integer and also apply the value you expect in case the value is Nothing.
If it is impossible that a instance with a Nothing set for the year reaches this method you can simply use the Value property.
I still do not fully understand why you get this strange error message. Maybe you could check out what the actual method that is called is? Pointing at the method should give you that information. It can't be Nullable(Of Integer).ToString
Well, I found a workable solution and something of an answer thanks to #Nitram's comment. The type of Year/Month property has been changed from Integer to Integer?. Obviously, this isn't a very satisfying answer because I still don't understand why the nullable int can't be formatted, and yet the code compiles perfectly. The working solution for me has been using static format method on String as so:
expirationDate = String.Format("{0:D4}-{1:D2}", model.Year, model.Month)
This works fine even with nullable types.
When designing data tables in the .xsd designer in Visual Studio, there is a property that specifies what to do when the table encounters a null value:
The problem is, if the DataType is System.DateTime, I'm unable to return empty or nothing. It always throws an exception.
As I work around, I can do the following:
If(row.IsDateLastRecallPrintedNull, DateTime.MinValue, row.DateLastRecallPrinted)
But if the value is DbNull.Value, I'd rather just have it return that.
Using IsDateLastRecallPrintedNull isn't a workaround, it's the way it's intended to be used. If you use a nullable date, you can set this to nothing rather than DateTime.MinValue in your code. Alternatively you can change the datatype in the dataset to System.Object, and then you can select '(Nothing)' in the dropdown. Note that you can overtype the NullValue entry in the properties with another value that's appropriate for the data type, although it won't work if you enter DateTime.Minvalue - it'll appear to accept it, but then fail - but you can put in another magic number such as 01/01/1900.
All this is 'by design'.*
Using databinding sidesteps this quagmire to a great extent; if you're reading programmatically from the dataset then IsxxxNull is the way to go.
*I suspect this is too often a Microsoftism for 'we didn't finish it by ship date'
I have been asked to find out why an ajax call doest work if date fields are left blank on a web form, finding out was easy, its because the VB function expects an object with a Date type.
I'm going to convert these values to Nullable(Of Date), but I'm reluctant as this is a class that's quite heavily used and I don't want to break anything else.
My thinking however is that everything calling this class must be sending in a correct Date or it would throw an error currently, so I should be ok.
As long as I check for a value using HasValue and get the date out using Value then I shouldn't have any problems, or is there something else I need to consider?
If you change every reference to use the Date's Value property it will be no worse than what you have now. Then you can add the HasValue checks where you need to.
When using the Ext.data.Store 'mapping' config property, of 'x.y', and the mapped model does not contain an 'x' property, the store throws an exception, which, prevents the store data from rendering into the grid view on data store load.
If the store source is out of your control, is it possible to avoid/catch the exception when the root of the mapping path does not exist. I've tried using a 'convert' function for the target property of the data store. The mapping path into the JSON document is only determined from the run context [e.g. this.mappingPath]. Dynamically generating the convert function (to catch the exception) seems to slow down the page a bit.
Is there a solution to null results along the model's mapping path within the ExtJS API, or is catching the exception from within the convert function the way to go? Or possibly another solution...
I ended up just using a convert function with a call to a 'followPath' type function anywhere that this was the case. Follow path breaks up the mapping component into it's parts (split on '.') and iterates through the list readjusting the context to context = context[part] along the way. so the call is followPath(item.data,path). This performs well, and gets the job done.
I have a really simple WCF service operation GetCurrentBalance. It returns a decimal.
I also have the odatagen generated entity files included in the project, which contains an implementation of the GetCurrentBalance operation returning a string. Calling this method returns me an XML string with the desired value in it.
I also tried using executeServiceOperation method in the generated class and pass in the operation name as a parameter, the returned value again is the same XML string.
Is there a way to extract this value? Or do I have to write a custom parser for it?
Thanks in advance.
Without further informations, if the returned value is a formatted XML string you may try extracting the value using XPath queries, have a look at this to get you started