I want to have a computed property that tracks that historical max of another property. Both these attributes are a member of an ndb class.
My naive approach was the following:
number = ndb.IntegerProperty(default=0)
highest_ever_number = ndb.ComputedProperty(lambda self: self.highest_ever_number if self.highest_ever_number >= self.number else self.number)
The intent was to set the highest_ever_number to a new number if number ever surpassed highest_ever_number.
This doesn't work because highest_ever_number is initially unset. I cannot set it to a default value using "default=0". Is there a workaround to this?
Thanks
I don't think you can use such conditions inside a Computed Property. This whole functionality can be done within a function, so it doesn't need to be a ComputedProperty. A better alternative to this problem could be to create a class method and call it whenever necessary.
Instead of using a computed property, you should use a normal IntegerProperty but use a _pre_put hook (https://cloud.google.com/appengine/docs/standard/python/ndb/modelclass#hooks) to verify/update highest_ever_number.
I can't test it right now, but this might do the trick:
number = ndb.IntegerProperty(default=0)
highest_ever_number = ndb.ComputedProperty(lambda self: self.highest_ever_number if
self.highest_ever_number and self.highest_ever_number >= self.number else self.number)
Related
Please give me a hint how to parameterize a link element in QTP...As we can parameterize 'WebEdit' element/object ,can we parameterize 'Link' element/object and how can we?
By parameterizing, do you mean Parameterizing the properties of the Link element to identify it using Descriptive Programming? Or is it something else?? Please elaborate!!
You can build a function like the one below for each object type that you want to use.
public Function CreateLinkDescription(LinkInnerTextValue, LinkHrefValue)
Set objLink = Description.Create()
objLink("innertext").Value = LinkInnerTextValue
objLink("href").Value = LinkHrefValue
'Add any other properties that you want to specify in the same fashion as above
Set CreateLinkDescription = objLink
End Function
Is there an example anywhere of a form that performs running totals in a column located within a grid. The user ordering and filtering of the grid would affect the running totals column.
I can easily perform the above if it was ordering only by transaction date, but including the user ordering and filtering I presume that we would have to use the datasource range() and rangecount() functions (see SysQuery::mergeRanges() for an example) then iterate over these to apply the filtering, then include the dynalinks. The same for the ordering, albeit this is now more complicated.
Any suggestions appreciated. Any appreciations suggested (as in: vote the question up!).
You could implement it as a form datasource display method using this strategy:
Copy the form's datasource query (no need for SysQuery::mergeRanges):
QueryRun qr = new QueryRun(ledgerTrans_qr.query());
Iterate and sum over your records using qr, stop after the current record:
while (qr.next())
{
lt = qr.getNo(1);
total += lt.AmountMST;
if (lt.RecId == _lt.RecId)
break;
}
This could be made more performant if the sorting order was fixed (using sum(AmountMST) and adding a where constraint).
Return the total
This is of cause very inefficient (subquadratic time, O(n^2)).
Caching the results (in a map) may make it usable if there are not too many records.
Update: a working example.
Any observations or criticisms to the code below most welcome. Jan's observation about the method being slow is still valid. As you can see, it's a modification of his original answer.
//BP Deviation Documented
display AmountMST XXX_runningBalanceMST(LedgerTrans _trans)
{
LedgerTrans localLedgerTrans;
AmountMST amountMST;
;
localLedgerTrans = this.getFirst();
while (localLedgerTrans)
{
amountMST += localLedgerTrans.AmountMST;
if (localLedgerTrans.RecId == _trans.RecId)
{
break;
}
localLedgerTrans = this.getNext();
}
return amountMST;
}
I need to know how I can parse a variable path in Flex 3 & e4X. For example, I have two XML strings where the name of one element is the only difference.
<NameOfRoot>
<NameOfChild1>
<data>1</data>
</NameOfChild1>
</NameOfRoot>
<NameOfRoot>
<NameOfChild2>
<data>2</data>
</NameOfChild2>
</NameOfRoot>
Currently I am accessing variables like this:
var data1:String = NameOfRoot.*::NameOfChild1.*::data;
var data2:String = NameOfRoot.*::NameOfChild2.*::data;
I would rather make this task more abstract so that if "NameOfChild3" is introduced I do not need to update the code. For example:
var data:String = NameOfRoot.*::{variable}.*::data;
Does anyone have insights into how this can be done?
Use the child property (LiveDocs example here):
var tagName:String = "NameOfChild1";
var data:String = NameOfRoot.child(tagName).data;
That's with no namespacing--not sure whether it's necessary in your case, but I assume you'd add some *::'s?
this also works:
var data:String = NameOfRoot..data;
but if you have more than 1 data node you'll have to sort some stuff out.
It looks like the ".*." operation will work. I wonder if this is the easiest way to handle this problem.
var data:String = NameOfRoot.*.*::data;
I need to access columns of infragistics ultragrid in same sequence in which they are being displayed in grid. If i can get the index of column in same sequence as they are visible on grid, i can fix my issues.
Thanks in advance.
Lalit
UltraGridColumn column = this.ultraGrid1.DisplayLayout.Bands[0].Columns[0];
Debug.WriteLine( "Columns in visible order: ");
// Get the first visible column by passing in VisibleRelation.First.
column = column.GetRelatedVisibleColumn( VisibleRelation.First );
while ( null != column )
{
Debug.WriteLine( " " + column.Key );
// Get the next visible column by passing in VisibleRelation.Next.
column = column.GetRelatedVisibleColumn( VisibleRelation.Next );
}
http://help.infragistics.com/Help/NetAdvantage/NET/2008.2/CLR2.0/html/Infragistics2.Win.UltraWinGrid.v8.2~Infragistics.Win.UltraWinGrid.UltraGridColumn~GetRelatedVisibleColumn.html
I suppose you could try to handle the event that is fired when the order is changed and keep track of all the changes, but this seems like it is asking for subtle bugs to creep in.
I considered looping through all the columns and trying to use some property that would tell me their current position (maybe the TabOrder?) and use that to compile an inorder list of the columns. I guess you might have to loop through each colum using the Column.GetRelatedVisibleColumn() method.
I have not actually implemented it yet as I have other higher priority issues but that may be the road I end up going down.
This is an old question, but I recently had same issue and solved it this way:
var selectedCells = this.Selected.Cells;
List<int> columns = new List<int>();
foreach (var cell in selectedCells)
{
if (!columns.Contains(cell.Column.Index))
columns.Add(cell.Column.Index);
}
columns.Sort((x, y) => this.DisplayLayout.Rows.Band.Columns[x].Header.VisiblePosition.CompareTo(this.DisplayLayout.Rows.Band.Columns[y].Header.VisiblePosition));
You can then use columns to access columns in order they are shown.
I am trying to access an XMLList item and convert it to am XML object.
I am using this expression:
masonicXML.item.(#style_number == styleNum)
For example if there is a match everything works fine but if there is not a match then I get an error when I try cast it as XML saying that it has to be well formed. So I need to make sure that the expression gets a match before I cast it as XML. I tried setting it to an XMLList variable and checking if it as a text() propertie like this:
var defaultItem:XMLList = DataModel.instance.masonicXML.item.(#style_number == styleNum);
if(defaultItem.text())
{
DataModel.instance.selectedItem = XML(defaultItem);
}
But it still give me an error if theres no match. It works fine if there is a match.
THANKS!
In my experience, the simplest way to check for results is to grab the 0th element of the list and see if it's null.
Here is your code sample with a few tweaks. Notice that I've changed the type of defaultItem from XMLList to XML, and I'm assigning it to the 0th element of the list.
var defaultItem:XML =
DataModel.instance.masonicXML.item.(#style_number == styleNum)[0];
if( defaultItem != null )
{
DataModel.instance.selectedItem = defaultItem;
}
OK I got it to work with this:
if(String(defaultItem.#style_number).length)
Matt's null check is a good solution. (Unless there is the possibility of having null items within an XMLList.. probably not, but I haven't verified this.)
You can also check for the length of the XMLList without casting it to a String:
if (defaultItem.#style_number.length() > 0)
The difference to String and Array is that with an XMLList, length() is a method instead of a property.