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This opens up special handling of user input and "user shortcuts" in the UI. For example accepting only a number as a time entry. | This opens up special handling of user input and "user shortcuts" in the UI. For example accepting only a number as a time entry. | ||
[[File:TimeSpent class example.png|left|thumb]] | |||
This example uses ''FromTimeText'', ''HoursText'' and ''ToTimeText'' for user input, but only '''FromTime''' and '''Hours''' for storing information in the database. | |||
'''/Date''' is a derived attribute for easy access to a neighboring class' containing the date in DateTime format. | |||
'''/EffectiveToTime''' is a derived attribute used a companion to the FromTime, again for symmetry in access the information. | |||
Support function '''StringToTime()''' | |||
To help the other function with conversion, a help function like this was created | |||
if aText.length <= 2 then | |||
DateTime.Parse('1900-01-01 ' + aText + ':00') | |||
else | |||
DateTime.Parse('1900-01-01 ' + aText) | |||
endif | |||
===== Property inspector ===== | |||
Below is the property inspector setting for an derived settable attribute. Note the AttributeMode and then the Ocl and OclSet code. | |||
[[File:DerivedSettable property inspector.png|none|thumb|382x382px]] | |||
===== /FromTimeText: String? ===== | |||
OCL | |||
if self.FromTime.notNull then | |||
self.FromTime.formatDateTime('HH:mm') | |||
else | |||
String.nullValue | |||
endif | |||
EAL (OclSet) | |||
self.FromTime := self.StringToTime(vInputParameter) | |||
'''/HoursText: String?''' | |||
OCL | |||
self.Hours.ToString('N2').Replace('.', ',') | |||
EAL | |||
self.Hours := Decimal.Parse(vInputParameter.Replace(',', '.')).Round(2) | |||
'''/ToTimeText: String?''' | |||
OCL | |||
if self.FromTime.notNull then | |||
self.FromTime.AddHours(self.Hours.Value.ToDouble).formatDateTime('HH:mm') | |||
else | |||
String.nullValue | |||
endif | |||
EAL | |||
if self.FromTime.notNull then | |||
self.Hours := Decimal.Create(self.StringToTime(vInputParameter).Subtract(self.FromTime).TotalHours) | |||
else | |||
self.FromTime := self.StringToTime(vInputParameter).AddHours(-self.Hours.ToDouble); | |||
0 | |||
endif | |||
Revision as of 12:37, 26 November 2017
Derived attributes use and OCL expression to calculate the presentation of another attribute.
Derived settable attributes use EAL to do the reverse, i.e. setting the source attribute from the entered value.
This opens up special handling of user input and "user shortcuts" in the UI. For example accepting only a number as a time entry.
This example uses FromTimeText, HoursText and ToTimeText for user input, but only FromTime and Hours for storing information in the database.
/Date is a derived attribute for easy access to a neighboring class' containing the date in DateTime format.
/EffectiveToTime is a derived attribute used a companion to the FromTime, again for symmetry in access the information.
Support function StringToTime()
To help the other function with conversion, a help function like this was created
if aText.length <= 2 then
DateTime.Parse('1900-01-01 ' + aText + ':00')
else
DateTime.Parse('1900-01-01 ' + aText)
endif
Property inspector
Below is the property inspector setting for an derived settable attribute. Note the AttributeMode and then the Ocl and OclSet code.
/FromTimeText: String?
OCL
if self.FromTime.notNull then
self.FromTime.formatDateTime('HH:mm')
else
String.nullValue
endif
EAL (OclSet)
self.FromTime := self.StringToTime(vInputParameter)
/HoursText: String?
OCL
self.Hours.ToString('N2').Replace('.', ',')
EAL
self.Hours := Decimal.Parse(vInputParameter.Replace(',', '.')).Round(2)
/ToTimeText: String?
OCL
if self.FromTime.notNull then
self.FromTime.AddHours(self.Hours.Value.ToDouble).formatDateTime('HH:mm')
else
String.nullValue
endif
EAL
if self.FromTime.notNull then
self.Hours := Decimal.Create(self.StringToTime(vInputParameter).Subtract(self.FromTime).TotalHours)
else
self.FromTime := self.StringToTime(vInputParameter).AddHours(-self.Hours.ToDouble);
0
endif