I am trying to check if the 'Listivew.Tag property is nothing'.
I used to do the 'Is Nothing' check universally for all scenarios as first check to avoid errors
Can someone explain how to do it in VB 6?
If Not .lvwLocation.Tag Is Nothing Then
'COMPANY
str = str & IIf(Len(.lvwLocation.Tag) > 0, " and u.location_id in " & .lvwLocation.Tag, "")
End If
Gives error 'type-mismatch'
Nothing is a valid value for Object variables, and Is is the way to compare object pointers.
But a VB6 control's Tag property is a String, and VB6's String type is not an Object; it's a primitive type. That means a String variable can't be assigned Nothing -- its emptiest possible value is the empty string. (And an Object variable can't be assigned a String value.) For strings just use the same equality/inequality/comparision operators that you use for other primitive (numeric/boolean/date) types:
If .lvwLocation.Tag <> "" Then ...
In VB6 it appears that using Is Nothing to compare Objects works, Every other data type that I tried did not. In .Net Nothing represents the default value of any data type and will work like you expect.
Dim test as Object
If Not test Is Nothing Then
/////
End If
Since it appears the data type of th Tag property in VB6 is a string. I would use something like:
If .lvwLocation.Tag <> "" Then
/////
End If
Related
I know that with Descriptive programming you can do something like this:
Browser("StackOverflow").Page("StackOverflow").Link("text:=Go To Next Page ", "html tag:=A").Click
But is it possible to create some kind of string so I can assign more than one data value and pass it as single variable? I've tried many combinations using escape characters and I always get error.
For example in the case above, let's say I have more properties in the Page object, so I'd normally have to do something like this:
Browser("StackOverflow").Page("name:=StackOverflow", "html id:=PageID")...etc...
But I'd like to pass "name:=StackOverflow", "html id:=PageID" as a single variable, so when writing many objects I'd only have to write:
Browser(BrowserString).Page(PageString).WebEdit("name:=asdfgh")
And the first part would remain static, so if the parents' data needs to be modified I'd only have to modify two variables and not all the objects created in all libraries.
Is it possible?
If I was not clear enough please let me know.
Thank you in advance!
I think what you're looking for is UFT's Description object
This allows you finer grained control on the description since in descriptive programming all values are regular expressions but with Description you can turn the regular expression functionality off for a specific property.
Set desc = Description.Create()
desc("html tag").Value = "A"
desc("innertext").Value = "More information..."
desc("innertext").RegularExpression = False
Browser("Example Domain").Navigate "www.example.com"
Browser("Example Domain").Page("Example Domain").WebElement(desc).Click
If you want to represent this with plain string then it's a bit more of a problem, you can write a helper function but I'm not sure I would recommend it.
Function Desc(descString)
Set ret = Description.Create()
values = Split(descString, "::")
For Each value In values
keyVal = Split(value, ":=")
ret(keyVal(0)).Value = keyVal(1)
Next
Set Desc = ret
End Function
' Usage
Browser("StackOverflow").Page("StackOverflow").WebElement(Desc("html tag:=H2::innertext:=some text")).Click
Further reading about descriptive programming.
As an alternative to Motti's excellent answer, you could also Set a variable to match your initial descriptive object and then extend it as required:
Set myPage = Browser("StackOverflow").Page("name:=StackOverflow", "html id:=PageID")
after which you can then use
myPage.WebEdit("name:=asdfgh")
throughout the rest of the code, so long as the myPage object stays in scope...
I have a recordset like this:
Dim rs as Recordset
Set rs as New Recordset
'... a lot of coding ...
if Err.Number <> 0 Then ' oops, something gone wrong!
If rs.State <> adStateClosed Then rs.Close
Set rs = Nothing
end if
' I want to evaluate if rs is Nothing, or Null
if rs is Nothing then
' this doesn't throw errors, and works well :D
end if
if rs is Null then
' this throws an error of "types not compatible"
end if
if rs = Null then
' this throws an error of "types not compatible"
end if
if isNull(rs) then
' never enters here, isNull(rs) evaluates to False
end if
I found out that in VB6 I rarely use "Null" (I used it for evaluating empty recordset schema names), but I use "Nothing" for stuff like images, adodb.connections or recordsets. For strings I have vbNullString. I read it is a pointer to a null string.
Is "Null" like a "unknown variable value" and "Nothing" a true null value?
Null is a specific subtype of a Variant. It has no existence outside of the Variant type, and is created to allow a Variant to model a database null value.
Nothing is a value of an Object variable. It essentially is identical to a null pointer, i.e. there is no object.
The following raises an error because "Is" can only be used with Object variables:
if rs is Null then
' this throws an error of "types not compatible"
end if
The following raises an error because an Object variable can never be Null:
if rs = Null then
' this throws an error of "types not compatible"
end if
The following evaluates False because IsNull() takes a Variant argument.
if isNull(rs) then
' never enters here, isNull(rs) evaluates to False
end if
It is equivalent to:
VarType(rs) = vbNull
The following table explains how to use VBScript keywords.
Empty
The Empty keyword is used to indicate an uninitialized variable value. This is not the same thing as Null.
False
The False keyword has a value equal to 0.
Nothing
The Nothing keyword in VBScript is used to disassociate an object variable from any actual object. Use the Set statement to assign Nothing to an object variable. For example:
Set MyObject = Nothing
Several object variables can refer to the same actual object. When Nothing is assigned to an object variable, that variable no longer refers to any actual object. When several object variables refer to the same object, memory and system resources associated with the object to which the variables refer are released only after all of them have been set to Nothing, either explicitly using Set, or implicitly after the last object variable set to Nothing goes out of scope.
Null
The Null keyword is used to indicate that a variable contains no valid data. This is not the same thing as Empty.
True
The True keyword has a value equal to -1.
You can try as follow:
a = "SELECT SBio.biosrno,YearlyCharges.adnum,Name,sName
FROM SBio RIGHT JOIN YearlyCharges ON SBio.biosrno=YearlyCharges.adnum
WHERE (SBio.biosrno IS NULL );"
I was trying to run below script, but it's giving me an error that says:
object doesn't support this property or method: "dbrowser.GetRoProperty"
SystemUtil.Run "iexplore.exe","http://usps.com/"
Set dbrowser = description.Create
dbrowser ("micclass").value = "Browser"
dbrowser("openurl").value = "https://www.usps.com"
dbrowser("title").value = "USPS - The United States Postal Service (U.S. Postal Service)"
print(dbrowser.getroproperty("title"))
Your dbrowser object is of type Description not Browser you need to create a Browser object based on this description. Replace the last line with:
Print Browser(dbrowser).GetROProperty("title")
Note, there are two changes here
Using Browser(dbrowser)
Removing the parens from the print sub.
Edit: also note that descriptions are regular expressions by default so the parens in the title may cause problems, you should mark it as not regex.
dbrowser("title").RegularExpression = False
Description.Create is used to create a 0-based Properties collection object. The variable dbrowser is preceded by the Set statement. Usage of Set statement binds an object as a reference to another object. Therefore, dbrowser becomes an object reference to the description object represented by Description.Create
A description object does not have a stand-alone use, but coupled with the ChildObjects method, it becomes an extremely powerful approach in dealing with AUT’s objects .For More Info, check link
So the code should be like
SystemUtil.Run "iexplore.exe","http://usps.com/"
wait(10)
Set dbrowser = description.Create
dbrowser ("micclass").value = "Browser"
dbrowser("openurl").value = "https://www.usps.com"
dbrowser("title").value = "USPS.*" ''Using Regular Expression here
Set colObject = Desktop.ChildObjects( dbrowser )
Print (colObject(0).GetROProperty("title"))
My question involves the use of QTP / VBScript.
Goal: From the qtp main starting file, initialize an array of classes, and pass that array as a parameter to a re-usable action via a parameter.
Problem: I am not able to pass an array of classes to my re-usable action.
Details:
I have two files: “application_main” and “personal_action”.
application_main is the entry point into qtp/vbscript.
personal_action is a re-usable action
Inside application_main, we have a call to InvokeApplication, proceeded by a few other declarations.
I am able to initialize an array and proceed to pass it as a parameter from my application_main to my personal_action:
From application_main:
Dim myArray
myArray = new Array(object1, object2, object3)
RunAction “personal_action”, oneIteration, myInteger, myBoolean, myArray
On the personal_action page, I edit the parameter properties via:
Edit->Action->ActionProperties. I select the Parameters tab.
In it, I have the option to define the amount of incoming parameters and each individual type. These available types seem to be restricted to:
String, Boolean, Date, Number, Password, Any
I set my 1st parameter as: Number
I set my 2nd parameter as: Boolean
I set my 3rd parameter as: Any
Upon running, I am prompted with this:
The type you specified for the ‘myArray’ parameter in your RunAction
statement does not match the type defined in the action.
Question: I am able to pass the Number and Boolean fine, but when an array is involved, qtp/vbscript doesn't seem to handle it well. Why am I not able to pass an array to an action via parameters from the main startup file? This seems like a common and simple task. Could I be so wrong?
Any help is appreciated. Thank you.
As per my knowledge, QTP will NOT allow this. There is no parameter type that can be used to represent an Array. This might be a limitation of QuickTest Professional.
Rather than passing array you can pass the Array elements as a string separated with delimiters.
Example:
"Item1^Item2^............" where "^" is the delimiter
then you can use split function of vb script, to get your array back.
Again doing the same thing with object,we have to give try for this
use lib file in your action ...
Create array public in lib
but in end for any case test or interation vararray=null
rodrigonw.
Sugestion... use function for include your lib in your actions (lib path)
Lib soluction
''######################################LIB"
'lib Passsagem de valores entre array
Dim arrayyy()
Sub setArrayyy(strvalores,redimencionaArray)
On error resume next
tamanho=UBound(arrayyy,1)
If Err.Number=9 then
ReDim arrayyy(0)
redimencionaArray=false
end if
err.Clear
On error goto 0
If redimencionaArray Then
tamanho=tamanho+1
ReDim preserve arrayyy(tamanho)
end if
arrayyy(tamanho)=strvalores
'arrayyy=arrayyy
End Sub
function getArrayyy() getArrayyy=arrayyy End function
''######################################"'Action X
call setArrayyy("X",false)
call setArrayyy("A",true)
call setArrayyy("D",true)
call setArrayyy("B",true)
''######################################'Action y
x=getArrayyy()
for countx=0 to ubound(x)
msgbox x(countx)
next
I'm banging my head against the wall on this one. I was looking at some old database reporting code written in VB6 and came across this line (the code is moving data from a "source" database into a reporting database):
rsTarget!VehYear = Trim(Str(rsSource!VehYear))
When rsSource!VehYear is Null, the above line generates an "Invalid use of Null" run-time error. If I break on the above line and type the following in the Immediate pane:
?rsSource!VehYear
It outputs Null. Fine, that makes sense. Next, I try to reproduce the error:
?Str(rsSource!VehYear)
I get an "Invalid use of Null" error.
However, if I type the following into the Immediate window:
?Str(Null)
I don't get an error. It simply outputs Null.
If I repeat the same experiment with Trim() instead of Str(), everything works fine. ?Trim(rsSource!VehYear) returns Null, as does ?Trim(Null). No run-time errors.
So, my question is, how can Str(rsSource!VehYear) possibly throw an "Invalid use of Null" error when Str(Null) does not, when I know that rsSource!VehYear is equal to Null?
Update: If I type the following in the Immediate window, it works as expected (no error occurs):
?Str(rsSource!VehYear.Value)
This outputs Null. Now, I know that rsSource!VehYear is actually an ADODB.Field instance, but Value is its default property, so Str should be operating on the Value property (which is Null). Even the error message ("Invalid use of Null") suggests that Str is receiving a Null parameter, but how can it treat Null differently in one case and not the other?
My only guess is the internal implementation of Str() is somehow failing to get the default property, and the "Invalid use of Null" error is happening for a different reason (something other than the parameter is causing the "Invalid use of Null", perhaps when it is trying to retrieve the default property from the Field object).
Does anyone have a more detailed, technical explanation for what is actually happening here?
In short:
?Str(rsSource!VehYear)
throws an "Invalid use of Null" error when rsSource!VehYear is Null, but
?Str(rsSource!VehYear.Value)
returns Null.
However, both Trim(rsSource!VehYear) and Trim(rsSource!VehYear.Value) return Null.
If you need a value other than a string, try using IsNull instead:
rsTarget!VehYear = IIf(IsNull(rsSource!VehYear), 0, rsSource!VehYear)
' Note 0 is the default value
The Str function will specifically check if a Null value is passed in and deal with it accordingly. When you pass in an object it attempts to convert the result of a default method to a String. The result of the default method is not passed into the Str method, but Field object is, so a check for the initial Null will fail. The Str function will continue to check the parameter type for datatypes that it supports when it realizes that it has an object, it will attempt to retrieve the default value. It doesn't re-attempt to deal with the default value as it did with the passed in argument, so the attempt to return a Null as a String will fail. It seems MS didn't expect a default value to be Null or any other invalid value for Str. For instance Str doesn't support an empty string either.
This was my workaround in the vb6-days:
rsTarget!VehYear = Trim(Str(rsSource!VehYear & ""))
the & "" will make sure there is allways at least an empty string to work with.
From memory, null database fields are Nothing (or possibly vbNull), which do not have the same rules applied to them as Null. You should just be able to do a quick check:
If (rsSource!VehYear Is Nothing) Then
' Null
Else
' Not null
End If