I am using a custom overloaded SaveChanges to implement some auditing functionality. The functionality works perfectly with the exception of some unexpected behaviour in relation to dates. In this example I'm changing a date field value from 1st May 2014 to 2nd May 2014:
A change is made to the database here:
Public Function UpdateTask(request As DataSourceRequest, ThisTask As JobTasksVM) As JsonResult
Dim cu As ApplicationUser = GetCurrentUser()
Dim CurrentTask = db.events.Find(ThisTask.id)
CurrentTask.start_date = ThisTask.start '<--- 2/5/2014 (ie 2nd May 2014), was previously 1/5/2014
CurrentTask.date = ThisTask.end
CurrentTask.task_name = ThisTask.Title
db.SaveChanges(cu.Employee_id)
End Function
This is intercepted by my custom SaveChanges:
Public Overloads Function SaveChanges(userID As Integer) As Integer
For Each entry As dbentityentry In Me.ChangeTracker.Entries().Where(Function(e) e.State <> EntityState.Unchanged)
Dim startOriginal As DateTime = entry.OriginalValues.Item("start_date")
Dim StartCurrent As DateTime = entry.CurrentValues.Item("start_date")
etc....
The bizarre thing is that whilst CurrentTask.start_date that is committed clearly shows the correct (UK) date of 2/5/2014 (2nd May 2014) the values within the overloaded SaveChanges are:
startOriginal: 5/1/2014 (ie 5th Jan 2014) <-- seems to have changed to US culture
startCurrent: 2/5/2014 (ie 2nd May 2014) <---as expected
I need to use the Original values in my audit functionality so this is causing a problem. I have also tried:
entry.CurrentValues.SetValues(entry.GetDatabaseValues)
But this also loads in the erroneous (ie US format 5/1/2014) into the start_date field.
I've checked all the culture settings on the system and they are all correctly English-UK. This behaviour seems fundamentally inconsistent - am I missing something?!
Thanks
DateTime types do not have a format, they are simply a value (number of ticks since 1/1/0001).
You did not say where you are seeing the "wrong" format, whether ToString() output or in intellisense. If you use ToString to the Output window, you should see the UK format since ToString will use/respect the local culture setting of the computer.
Intellisense is culture agnostic and tries to use an unambiguous format: MM/dd/yyyy. This is the same "format" or order you have to use when creating a DateTime var from a literal:
Dim dt As DateTime = #1/5/2014# ' e.g. MM/dd/yyyy
' same as:
Dim dt As New DateTime(1, 5, 2014) ' mm, dd, yyyy
This is InvariantCulture (not US). When you hold the mouse over the var, the VB IDE will use the same order. It tries to make clear it is using the required literal/InvariantCulture format by displaying it with the hashes: #1/5/2014#.
Dim dt As DateTime = #2/11/2011#
Console.WriteLine(dt.ToString)
In the US, 2/11/2011 will display based on the culture
In the UK, it will be 11/2/2011
Intellisense will be #2/11/2011#
Related
In Visual Basic, I have an object with an ItemDate key in it with the value being assigned to a label in ASPX. Here is the code:
lblItemDate.Text = .ItemDate
The result on the front end is '2021/11/15'. I want the result to be: 'November 15, 2021'
What do I need to do in Visual Basic to make the result on the front end be 'November 15, 2021' instead of '2021/11/15'?
In another VB file, the ItemDate object key is created this way:
oItem.ItemDate = Trim(odbcReader("ItemDate").ToString)
Assuming you really have a .Net DateTime struct:
lblItemDate.Text = .ItemDate.ToString("MMMM dd, yyyy")
Otherwise you have a string, in which case you want to parse into a .Net DateTime struct so you can use the same ToString() call above:
Dim MyDate As DateTime = DateTime.ParseExact( .ItemDate, "yyyy/MM/dd")
lblItemDate.Text = MyDate.ToString("MMMM dd, yyyy")
Even better if you can update your code so ItemDate is a DateTime value in the first place, and the Parse() call is moved to the point where the object is first created.
It's been a while, so I don't recall whether the .ItemDate shortcut is available in the context of a function call. You may need to use the full version of the variable name.
Besides the .Net functions mentioned in another answer, which work across different languages, there is also the Format(..) function traditionally included with professional implementations of BASIC since the early 70's (I first used it in DEC's BASIC-Plus in 1976).
To get 'November 15, 2021' you'd do it like this:
lblItemDate.Text = Format(.ItemDate, "MMMM d, yyyy")
whenever I'm defining the timeframe being in German session language after changing to English lang. session (and vice versa) I'm getting the:
java.text.ParseException: Unparseable date: "10.10.2018"
Here is the fragment:
Date startDateFormatted = DateUtils.convertDateToMinusDayNumber(cal, dayRange);
Date endDateFormatted = new Date();
if (StringUtils.isNotEmpty(startDate) && StringUtils.isNotEmpty(endDate))
{
try
{
String datePattern = getLocalizedString("dd.MM.yyyy"); //
startDateFormatted = new SimpleDateFormat(datePattern).parse(startDate); // exception is throwing on this line
endDateFormatted = new SimpleDateFormat(datePattern).parse(endDate);
}
catch (final Exception e)
{
LOG.error(ERROR_DATE_PARSING, e);
}
}
java.time
I recommend you use java.time, the modern Java date and time API, for your date work.
String datePattern = "dd.MM.uuuu";
DateTimeFormatter dateFormatter = DateTimeFormatter.ofPattern(datePattern);
String startDateString = "10.10.2018";
LocalDate startDate = LocalDate.parse(startDateString, dateFormatter);
System.out.println(startDate);
Output:
2018-10-10
If you want to support different date formats for different locales, let Java handle that part for you:
String datePattern = DateTimeFormatterBuilder.getLocalizedDateTimePattern(
FormatStyle.MEDIUM, null, IsoChronology.INSTANCE, Locale.GERMAN);
German locale works with your example string of 10.10.2018. For UK locale, for example, a string like 10 Oct 2018 would be required instead, as Britons would typically expect.
What went wrong in your code?
We cannot tell from the information and code that you have provided exactly what happened. A couple of good guesses are:
As Arvind Kumar Avinash said in a comment, getLocalizedString() may be causing trouble. You may print datePattern to check. Localization is something you do to strings that you display to the user. Trying to localize a format pattern string for a formatter is probably plain wrong, so you should leave out that method call. That the error occurs when changing language seems to support this possibility.
There may be unexpected non-printing characters in your string. One way to check would be to print startDate.length(). If the length is greater than 10, there are more characters than the 10 chars in 10.10.2018.
Link
Oracle tutorial: Date Time explaining how to use java.time.
I seem to be losing the value of sessionScope variables between XPages when I load DateTime values from a Notes document (not from the XPage). Here is what I do:
I have an EditBox where the contents are set to type Date only:
<xp:inputText value="#{document1.datum}" id="datum" defaultValue="#{javascript:#Now()}" required="true">
<xp:this.converter>
<xp:convertDateTime type="date"></xp:convertDateTime>
</xp:this.converter>
<xp:dateTimeHelper></xp:dateTimeHelper>
</xp:inputText>
I then save this to a sessionScope variable :
sessionScope.put ("datum", getComponent("datum").getValue());
Then I change XPages by doing a:
var extCont = facesContext.getExternalContext();
extCont.redirect("xpNextPage.xsp")
I then do a sessionScope.get:
print (sessionScope.get ("datum"));
And the contents are fine.
if I do the same thing with a document that I have loaded:
var date:NotesDateTime = doc.getItemValueDateTimeArray("datum");
var start:NotesDateTime = doc.getItemValueDateTimeArray("von");
var dt:NotesDateTime = session.createDateTime (date [0].getDateOnly() + " " + start [0].getTimeOnly());
sessionScope.put ("datum", dt);
then switch to the next page and try and load it with:
print (sessionScope.get ("datum"));
I get a value null.
I have attached a screenshot of the problem (I printed other fields as well so you can see it is only the DateTime fields that are the problem). I do notice that the format of the DateTime value is different... could this be the problem?
NotesDataTime is not serializable, so you cannot store it in the memory. When you use getComponent("datum").getValue(), it returns you Java Date not NotesDataTime. Java date is serializable, so its working.
Try convert your NotesDataTime to Java Date.
dt.toJavaDate()
I am using Linq to entityframework to query some infomration. I am trying to use entityfunction.truncatetime and it doesnt seem to work as expected. here is my sample query
From d In Request
Where d.Requestor= "XXXX" And d.ProcessedFlag = "N"
Select d.RequestID, RequestReason = d.RequestReason.ItemValue, RequestType = d.RequestType.ItemValue, RequestedDate = EntityFunctions.TruncateTime(d.RequestedMoveDate)
The requesteddate doesnt seem to truncate the time part and I am still getting the both Date and time.
Am I missing something here?
In .NET, the DateTime class actually represents both a date and a time. Internally, this is stored as a numeric value represented by the number of 100-nanosecond "ticks" since Midnight, January 1, 1001 AD. This number gets "converted" when it's displayed (either in output or in a debugger). This conversion is done via a format string.
Even if you truncate a DateTime's time portion, it still has a time... it's just 00:00:00, and if you don't want to see that time, you need to adjust your format string to not convert that.
Thus, if you do something like this: DateTime.Now.Date it will display `10/15/2012 00:00:00" if you use the default date conversion string (or whatever is the default format for your culture).
If you want to only display the Date portion, then you must do something like myDate.ToShortDateString() or myDate.ToString("d").
EntityFunctions is a set of tools designed to be used in Linq to Entities queries, because doing DateTime formatting is not normally allowed in a query.
For example, this code does not work:
var q = from x in dc where x.BirthDate == DateTime.Now.AddYears(-15).Date select x;
You have to do it like this:
var q = from x in dc
where x.Birthdate == EntityFunctions.TruncateTime(DateTime.Now.AddYears(-15))
select x;
This will then generate the correct SQL to do date comparisons in SQL code. This is what the EntityFunctions are designed for, not truncating dates in the select portion (although it does work). But, even though the date is truncated, it will still have a Time component, it will just be 00:00:00, and you must use a date format string to present it to your users in the manner you intend.
cant you use ToShortDateString() like below?
List<DateTime> time = new List<DateTime>();
time.Add(DateTime.Now);
var WhatDate = from date in time
select new { Date = date.ToShortDateString() };
In your case try this
From d In Request
Where d.Requestor= "XXXX" And d.ProcessedFlag = "N"
Select new{ RequestID = d.RequestID, RequestReason = d.RequestReason.ItemValue, RequestType = d.RequestType.ItemValue, RequestedDate = d.RequestedMoveDate.ToShortDateString()};
I have to use java.util.Date class as field type in a table.
But I would like to change the display format of the date field with help of joda time (confortable, prefered to use), thats why I want to convert a Date to DateTime.
I know I oversee something, because there is no such a question in stackoverflow :) but I could not find the soulution among the DateTime constructors and so on.
The reverse conversion DateTime.toDate();
exists, but what about the opposite way ?
Thanks for the answers in advance.
Cs
In Vaadin, if you want to change display format in a table without joda, you simply override the method protected String formatPropertyValue(Object rowId, Object colId,
Property property)
Here an example to do it :
Table t = new Table() {
#Override
protected String formatPropertyValue(Object rowId, Object colId,
Property property) {
Object v = property.getValue();
if (v instanceof Date) {
Date dateValue = (Date) v;
return new SimpleDateFormat("yyyy-MMMM-dd").format(dateValue);
}
return super.formatPropertyValue(rowId, colId, property);
}
};
Regards
Éric
Yes, Use Joda-Time
Definitely use Joda-Time or the java.time package in Java 8 (inspired by Joda-Time). The old java.util.Date and java.util.Calendar classes are notoriously troublesome, confusing, and outmoded.
Also, read the Wikipedia pages on UTC and ISO 8601.
Yes, Pass Date To Joda-Time Constructor
➔ Yes indeed, you can pass a java.util.Date object to the constructor of a Joda-Time DateTime object.
The API doc is a bit confusing as this apparently falls into the catch-all version of the constructor taking an java.lang.Object instance. If that Object is in fact a java.util.Date, Joda-Time will extract its millisecond-count-since-epoch and use that number as its own.
Time Zone
A DateTime constructor also assigns a time zone. By default, the JVM’s current default time zone is assigned. I recommend you always pass a desired time zone rather than rely implicitly on the default even if that means calling getDefault.
Example Code
Here is some example code in Joda-Time 2.5 showing how to pass a java.util.Date to a Joda-Time constructor.
java.util.Date date = new java.util.Date();
DateTimeZone zone = DateTimeZone.forID( "America/Montreal" );
DateTime dateTimeMontreal = new DateTime( date , zone );
DateTime dateTimeUtc = dateTimeMontreal.withZone( DateTimeZone.UTC ); // Adjust to another time zone.
Dump to console.
System.out.println( "date: " + date ); // Misleading output. A j.u.Date is in UTC but its toString method applies JVM’s current default time zone.
System.out.println( "dateTimeMontreal: " + dateTimeMontreal );
System.out.println( "dateTimeUtc: " + dateTimeUtc );
When run.
date: Sat Oct 18 18:54:55 PDT 2014
dateTimeMontreal: 2014-10-18T21:54:55.740-04:00
dateTimeUtc: 2014-10-19T01:54:55.740Z
As shown in the Question, to go from a DateTime to java.util.Date, call toDate.
java.util.Date date = dateTimeMontreal.toDate();