I'm not an IT professional so apologies if I've missed something obvious.
When writing a program I add a class SettingsIni that reads a text file of keys and values. I find this method really flexible as settings can be added or changed without altering any code, regardless of what application I have attached it to.
Here's the main code.
Public Shared Sub Load()
Using settingsReader As StreamReader = New StreamReader(System.AppDomain.CurrentDomain.BaseDirectory & "settings.ini")
Do While settingsReader.Peek > -1
Dim line As String = settingsReader.ReadLine
Dim keysAndValues() As String = line.Split("="c)
settingsTable.Add(keysAndValues(0).Trim, keysAndValues(1).Trim)
Loop
End Using
End Sub
Public Shared Function GetValue(ByVal key As String)
Dim value As String = settingsTable(key)
Return value
End Function
This allows you to use a setting within your code by calling the SettingsIni.GetValue method.
For example:
watcher = New FileSystemWatcher(SettingsIni.GetValue("inputDir"), "*" & SettingsIni.GetValue("extn")).
I find this makes my code esay to read.
My problem is the values in this case, inputDir and extn, are typed freehand and not checked by intellisense. I'm always worried that I may make a typo in an infrequently used branch of an application and miss it during testing.
Is there a best practice method for retrieving settings? or a way around these unchecked freehand typed values?
A best practice for your code example would be to use Constants for the possible settings.
Class Settings
Const inputDir as String = "inputDir"
Const extn as String = "extn"
End Class
watcher = New FileSystemWatcher(SettingsIni.GetValue(Settings.inputDir), "*" & SettingsIni.GetValue(Settings.extn))
I assume you are using VB.NET?
If so, there is the handy "Settings"-menu under "my project". It offers a way to store the settings for your program and retrieve them via "my.settings.YOURKEY". The advantage is, that type securtiy is enforced on this level.
Additionally, you can also store "resources" almost the same way - but resources are better suited for strings / pictures etc. But they are expecially good if you want to translate your program.
As for your current problem:
Store the path in the settings, this way you do not need to change alll your code immidiately but you can use your system and never misspell anything.
If it's a number you could do these 3 things:
Check if is numeric - using IsNumeric function
Check if it is whole number - using Int function, like: if Int(number)=number
Check for the valid range, like: if number>=lowerbound and number<=upperbound
It totally depends on you. You are the one to check almost all the things inside quotes, not the intellisense.
But you still use Try-Catch block:
Try
Dim value As String = settingsTable(key)
Return value
Catch ex As Exception
MsgBox(ex.ToString)
Return ""
End Try
So you will get an message box if you are trying to access a non-existing setting that you may have mistyped.
Related
I have a form with a variable in it called "VigilTable." This variable gets its value from the calling string OpenArgs property.
Among other things, I use this variable in the call string when opening other forms.
But it only works the first call.
MsgBox VigilTable before the call will always show "Spring2022" or whatever on the first call but always comes up blank on succeeding calls (and I get "invalid use of NULL" when the called form attempts to extract the value from OpenArgs). The variable is dimmed as String in the General section of the form's VBA code.
So what's happening here? And can I fix it?
Thanks.
Ok, so you delcared a variable at the form level (code module) for that given form.
and we assume that say on form load, you set this varible to the OpenArgs of the form on form load.
So, say like this:
Option Compare Database
Option Explicit
Public MyTest As String
Private Sub Form_Load()
MyTest = Me.OpenArgs
End Sub
Well, I can't say having a variable helps all that much, since any and all code in that form can use me.OpenArgs.
but, do keep in mind the following:
ONLY VBA code in the form can freely use that variable. It is NOT global to the applcation, but only code in the given form.
However, other VBA code outside of the form can in fact use this variable. But ONLY as long as the form is open.
So, in the forms code, you can go;
MsgBox MyTest
But, for VBA outside of the form, then you can get use of the value like this:
Msgbox forms!cityTest.MyTest
However, do keep in mind that any un-handled error will (and does) blow out all global and local variables. So, maybe you have a un-handled error.
Of course if you compile (and deploy) a compiled accDB->accDE, then any errors does NOT re-set these local and global variables.
but, for the most part, that "value" should persist ONLY as long as the form is open, and if you close that form, then of course the values and variables for that form will go out of scope (not exist).
Now, you could consider moving the variable declare to a standard code module, and then it would be really global in nature, but for the most part, such code is not recommended, since it hard to debug, and such code is not very modular, or even easy to maintain over time.
So, this suggests that some error in VBA code is occurring, and when that does occur, then all such variables are re-set (but, the noted exception is if you compile down to an accDE - and any and all variables will thus persist - and even persist their values when VBA errors are encountered.
For a string variable, a more robust solution not influenced by any error, should be writing/reading in/from Registry. You can use the, let as say, variable (the string from Registry) from any workbook/application able to read Registry.
Declare some Public constants on top of a standard module (in the declarations area):
Public Const MyApp As String = "ExcelVar"
Public Const Sett As String = "Settings"
Public Const VigilTable As String = "VT"
Then, save the variable value from any module/form:
SaveSetting MyApp, Sett, VigilTable , "Spring2022" 'Save the string in Regisgtry
It can be read in the next way:
Dim myVal as String
myVal = GetSetting(MyApp, Sett, VigilTable , "No value") 'read the Registry
If myVal = "No value" Then MsgBox "Nothing recorded in Registry, yet": Exit Sub
Debug.print myVal
Actually, this proved not to be the the answer at all.
It was suggested that I declare my variables as constants in the Standard module but I declared them as variables. It appeared at first to work, at least through one entire session, then it ceased to work and I don't know why.
If I declare as constants instead, will I still be able to change them at-will? That matters because I re-use them with different values at different times.
I didn't do constants but declaring VigilName in the Standard module and deleting all other declarations of it fixed both problems.
While I was at it I declared several other variables that are as generally used and deleted all other declarations of them as well so that at least they'll be consistently used throughout (probably save me some troubleshooting later.
Thanks to all!
I am working on an MS Access database application that was created by someone else. There is one particular line of code (a Function) that will randomly get called and I have no idea why it is being called or what it does. I have searched (ctrl+F) the entire project for something that calls this function but I can't find it. How can I find out why this Function is being called? (See below). Thank you!
Public Function Concat(strIOSC As String, strFeature As String) As String
Static strLastIOSC As String
Static strFeatures As String
If strIOSC = strLastIOSC Then
strFeatures = strFeatures & ", " & strFeature
Else
strLastIOSC = strIOSC
strFeatures = strFeature
End If
Concat = strFeatures
End Function
If you have only searched the scripts and modules, then your scope is too narrow.
A public function like this can also be used in expressions, so you need to check queries, reports, form controls, macros, and possibly even tables if you use calculated fields. Depending on the size of the database, and how often the function is called, you can either search manually in a targeted way or possibly use a public sub to output something searchable. This sub can get you started. I think it outputs every possible location for expressions. Unfortunately, each object will have its own text file which will need to be searched separately unless you build a sub to do that too.
As for what your function does, it looks like it logs each input using the Static strLastIOSC variable, compares to the arguments passed on the second function call, and if they match it concatenates the two strFeature inputs together and outputs the result.
So basically the first argument tells the function whether this is the beginning of a new concatenation instance, or the continuation of an existing instance. The second argument is the item to be concatenated.
The Static keyword means that the value is stored even after the function runs so it can compare the last call with the current call to determine whether to add the second argument to the one saved from before, or clear the memory and prepare for a new concatenation.
Given its design, it's probably being used in a query/report/form, where strIOSC is likely a primary key field or a field in a GROUP BY.
I am trying to check if an output column of my script component is NULL.
I tried to use the Row.Column_IsNull, but when I try to do the following:
If Row.Column_IsNull = True Then
// do something
End If
I get an error " Property Row.Column_IsNull is WriteOnly".
What the problem is
The key error in the above was is WriteOnly. When you are referencing columns in Script Components as Transformation, you can specify whether they are ReadOnly, ReadWrite.
When acting as Source, you don't have that option. It's WriteOnly (logically) and they don't even give you the option of the above dialog. So, when you're in your Source and attempt to access write only properties like the following code demonstrates, it breaks.
Public Overrides Sub CreateNewOutputRows()
Output0Buffer.AddRow()
' this is logically wrong
If Output0Buffer.Column_IsNull Then
End If
End Sub
The resolution is that you need to inspect whatever you are assigning into OutputBuffer0.Column prior to making the assignment (or create a separate boolean flag) to keep track of whether the current value was populated.
What the problem isn't
Keeping this here since I already ran down this rabbit hole
Since _IsNull is boolean, you can skip the explicit test and simply use
If Row.Column_IsNull Then
Originally, I had thought this was the classic C-like language issue of assignment (=) vs equality (==) but as #John Saunders was kind enough to point out, this was VB.
That said, the supplied code should work (it does for me).
Public Overrides Sub Input0_ProcessInputRow(ByVal Row As Input0Buffer)
Dim x As String
If Row.Src_IsNull = True Then
x = "" ' do nothing
End If
End Sub
Ive always been able to just search for what I need on here, and I've usually found it fairly easily, but this seems to be an exception.
I'm writing a program in Visual Basic 2010 Express, it's a fairly simple text based adventure game.
I have a story, with multiple possible paths based on what button/option you choose.
The text of each story path is saved in its own embedded resource .txt file. I could just write the contents of the text files straight into VB, and that would solve my problem, but that's not the way I want to do this, because that would end up looking really messy.
My problem is that I need to use variable names within my story, here's an example of the contents of one of the embedded text files,
"When "+playername+" woke up, "+genderheshe+" didn't recognise "+genderhisher+" surroundings."
I have used the following code to read the file into my text box
Private Sub frmAdventure_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
Dim thestorytext As String
Dim imageStream As Stream
Dim textStreamReader As StreamReader
Dim assembly As [Assembly]
assembly = [assembly].GetExecutingAssembly()
imageStream = assembly.GetManifestResourceStream("Catastrophe.CatastropheStoryStart.png")
textStreamReader = New StreamReader(assembly.GetManifestResourceStream("Catastrophe.CatastropheStoryStart.txt"))
thestorytext = textStreamReader.ReadLine()
txtAdventure.Text = thestorytext
End Sub
Which works to an extent, but displays it exactly as it is in the text file, keeps the quotes and the +s and the variable names instead of removing the quotes and the +s and replacing the variable names with what's stored within the variables.
Can anyone tell me what I need to change or add to make this work?
Thanks, and apologies if this has been answered somewhere and I just didn't recognise it as the solution or didn't know what to search to find it or something.
Since your application is compiled, you cannot just put some of your VB code in the text file and have it executed when it is read.
What you can do, and what is usually done, is that you leave certain tags inside your text file, then locate them and replace them with the actual values.
For example:
When %playername% woke up, %genderheshe% didn`t recognise %genderhisher% surroundings.
Then in your code, you would find all the tags:
Dim matches = Regex.Matches(thestorytext, "%(\w+?)%")
For Each match in matches
' the tag name is now in: match.Groups(1).Value
' replace the tag with the value and replace it back into the original string
Next
Of course the big problem still remains - which is how to fill in the actual values. Unfortunately, there is no clean way to do this, especially using any local variables.
You can either manually maintain a Dictionary of tag names and their values, or use Reflection to get the values directly at the runtime. While it should be used carefully (speed, security, ...), it will work just fine for your case.
Assuming you have all your variables defined as properties in the same class (Me) as the code that reads and processes this text, the code will look like this:
Dim matches = Regex.Matches(thestorytext, "%(\w+?)%")
For Each match in matches
Dim tag = match.Groups(1).Value
Dim value = Me.GetType().GetField(tag).GetValue(Me)
thestorytext = thestorytext.Replace(match.Value, value) ' Lazy code
Next
txtAdventure.Text = thestorytext
If you don't use properties, but only fields, change the line to this:
Dim value = Me.GetType().GetField(tag).GetValue(Me)
Note that this example is rough and the code will happily crash if the tags are misspelled or not existing (you should do some error checking), but it should get you started.
I have a VBA template project that runs automatically when a Word document is opened. However, if I open multiple documents, they all share the variables values. How can declare these variables to be only associated with the active window or active document?
I tried declaring them in a Class Module, but that did not help. Switching between opened document I can see that these variables are shared.
Any input is appreciated...
This what I have in my Module:
Option Private Module
Dim CurrentCommand As String
Public Function SetCurrentCommand(command)
CurrentCommand = command
End Function
Public Function GetCurrentCommand()
GetCurrentCommand = CurrentCommand
End Function
More Info: The code/Macro start at AutoExec like this:
Public Sub Main()
Set oAppClass.oApp = Word.Application
If PollingRate <> "" Then Application.OnTime Now + TimeValue(PollingRate), "CaptureUserViewState"
End Sub
And the CaptureUserViewState is a Sub that resides in a different Module and does all teh checks (comparing new values to last recorded ones) and here how this Sub does the check:
If WL_GetterAndSetter.GetLastPageVerticalPercentage <> pageVerticalPercentScrolled Then
'Update the last value variable
WL_GetterAndSetter.SetLastPageVerticalPercentage (pageVerticalPercentScrolled)
'log change
End If
You don't give us much information, but I assume you declared public variables at module level like this:
Public myString As String
Public myDouble As Double
From VBA documentation:
Variables declared using the Public statement are available to all procedures in all modules in all applications unless Option Private Module is in effect; in which case, the variables are public only within the project in which they reside.
The answer is to use Option Private Module.
When used in host applications that allow references across multiple projects, Option Private Module prevents a module’s contents from being referenced outside its project.
[...] If used, the Option Private statement must appear at module level, before any procedures.
EDIT You have now clarified that you declare your variables using Dim at module level. In this case, Option Private Module is irrelevant.
Variables declared with Dim at the module level are available to all procedures within the module.
i.e. regardless of whether you're using Option Private Module or not.
If you're finding that the values are retained between runs, then that must be because you are running a procedure from the same module from the same workbook. You may think you're doing something else, but in reality this is what you're doing.
EDIT
In your class module, instead of Dim CurrentCommand As String try Private CurrentCommand As String. Without more information it's hard to debug your program. I'm just taking random potshots here.
What you need to do is store multiple versions of the variables, one set per document.
So I would suggest that you create a simple class to hold the different values.
You then store them in a collection mapping the data-set with the document name or similar as the key.
In classmodule (MyData), marked as public:
Public data1 as String
Public data2 as Integer
In module with the event-handlers:
Dim c as new Collection 'module global declaration
Sub AddData()
Dim d as new MyData 'Your data set
d.data1 = "Some value"
d.data2 = 42
c.add Value:=d, Key:=ActiveDocument.name
End Sub
Then when you enter the event-handler you retrieve the data and use the specific set for the currently active document.
Sub EventHandler()
Dim d as MyData
set d = c.item(ActiveDocument.name)
'use data
'd.data1...
End Sub
Please not that this code is just on conceptual level. It is not working, You have to apply it to your problem but it should give you some idea on what you need to do. You will need to add alot of error handling, checking if the item is already in the collection and so on, but I hope you understand the concept to continue trying on your own.
The reason for this is because, as I understand the situation from your question, you only have one version of your script running, but multiple documents. Hence the script have to know about all the different documents.
On the other hand, If each document would have their own code/eventhandlers, hence having multiple versions of the script running, then you don't need the solution provided above. Instead you need to be careful what document instance you reference in your script. By always using "ThisDocument" instead of "ActiveDocument" you could achieve isolation if the code is placed in each open document.
However, as I understood it, you only have one version of the script running, separate from the open documents, hence the first solution applies.
Best of luck!
You might want to store the Document Specific details using
The Document.CustomDocumentProperties Property
http://msdn.microsoft.com/en-us/library/office/aa212718(v=office.11).aspx
This returns a
DocumentProperties Collection
Which you can add new Properties to Using
Document.CustomDocumentProperties.Add(PropertyName, LinkToContent, Value, Type)
And then Read From using
Document.CustomDocumentProperties.Item(PropertyName)
A downside, or bonus, here is that the properties will remain stored in the document unless you delete them.
This may be a good thing or a bad thing