Retrieve calendar items (Outlook API, WebDAV) displaying strange behaviour - vba

We are writing an MS Outlook plugin. To satisfy our business-logic, it should check all appointments between some dates. We are experiencing several problems with retrieving all items from calendars. We tried two options:
Outlook API. We use the standard logic that is described in MSDN - sort items by [Start], set IncludeRecurrences to True and run the Find\Restrict query over calendar items like here. It works fine in our test environment. However, in our customer's environment: For recurring appointments, start and end dates are set to the corresponding dates of a 'master appointment.' For example, in some room's calendar we have a weekly appointment that was created in January, and if we try to find all items in August, we get among others four items of this recurring appointment, but their start and end dates are set to January. But Outlook displays correct dates in the same calendar...
Very bad, but we still have WebDAV! We write a simple test application and try to query all items from the calendar using WebDAV. Of course, we didn't reinvent the wheel and just pasted the code from documentation. The previous problem is solved, but the next one arises: It doesn't return recurring items that were created more than approximately six months ago. I Haven't a clue - there are no parameters restricting 'old' items!
What is wrong? Are we missing something important?
Technical details: Exchange 2003, Outlook 2003-2010. Frankly speaking, the first error disappears if we turn on Cached Exchange Mode, but we can't do that.
var nameSpace = application.GetNamespace("MAPI");
var recepient = nameSpace.CreateRecipient(roomEMail);
recepient.Resolve();
var calendar = nameSpace.GetSharedDefaultFolder(recepient, OlDefaultFolders.olFolderCalendar);
var filter = string.Format("[Start]<'{1}' AND [End]>'{0}'",
dateFrom.ToString("dd/MM/yyyy HH:mm", CultureInfo.InvariantCulture), dateTo.ToString("dd/MM/yyyy HH:mm", CultureInfo.InvariantCulture)
);
var allItems = calendar.Items;
allItems.Sort("[Start]");
allItems.IncludeRecurrences = true;
var _item = allItems.Find(filter);
while (_item != null) {
AppointmentItem item = _item as AppointmentItem;
if (item != null) {
if (item.Subject != "some const")
&& (item.ResponseStatus != OlResponseStatus.olResponseDeclined)
&& (item.MeetingStatus != OlMeetingStatus.olMeetingReceivedAndCanceled
&& item.MeetingStatus != OlMeetingStatus.olMeetingCanceled))
{
/* Here we copy item to our internal class.
* We need: Subject, Start, End, Organizer, Recipients, MeetingStatus,
* AllDayEvent, IsRecurring, RecurrentState, ResponseStatus,
* GlobalAppointmentID */
}
}
_item = allItems.FindNext();
}
UPDATE 1:
Additional research using OutlookSpy shows that the problem is not in our code - the Start\End dates are incorrect inside the API when Cached Exchange Mode is off. But Outlook developers were aware of it, and they somehow display correct dates in calendars! Does anyone know how?
UPDATE 2:
Answer from Outlook Support Escalation Engineer:
Based on this, I can confirm that this is a problem in our product.

Possible cause:
Sort after setting IncludeRecurrences.
Here is my code of a PowerShell module that retrieves Outlook items between two dates.
And a little applet to check for changes and send an email including the agenda updates, which comes handy when you don't have mobile access to the Exchange.
Path: Documents\WindowsPowerShell\Modules\Outlook\expcal.ps1
Function Get-OutlookCalendar
{
<#
.Synopsis
This function returns appointment items from default Outlook profile
.Description
This function returns appointment items from the default Outlook profile. It uses the Outlook interop assembly to use the olFolderCalendar enumeration.
It creates a custom object consisting of Subject, Start, Duration, Location
for each appointment item.
.Example
Get-OutlookCalendar |
where-object { $_.start -gt [datetime]"5/10/2011" -AND $_.start -lt `
[datetime]"5/17/2011" } | sort-object Duration
Displays subject, start, duration and location for all appointments that
occur between 5/10/11 and 5/17/11 and sorts by duration of the appointment.
The sort is the shortest appointment on top.
.Notes
NAME: Get-OutlookCalendar
AUTHOR: ed wilson, msft
LASTEDIT: 05/10/2011 08:36:42
KEYWORDS: Microsoft Outlook, Office
HSG: HSG-05-24-2011
.Link
Http://www.ScriptingGuys.com/blog
#Requires -Version 2.0
#>
echo Starting... Initialize variables
Add-type -assembly "Microsoft.Office.Interop.Outlook" | out-null
$olFolders = "Microsoft.Office.Interop.Outlook.OlDefaultFolders" -as [type]
$olCalendarDetail = "Microsoft.Office.Interop.Outlook.OlCalendarDetail" -as [type]
echo ... Getting ref to Outlook and Calendar ...
$outlook = new-object -comobject outlook.application
$namespace = $outlook.GetNameSpace("MAPI")
$folder = $namespace.getDefaultFolder($olFolders::olFolderCalendar)
echo ... Calculating dates ...
$now = Get-Date -Hour 0 -Minute 00 -Second 00
echo From $a To $b
echo ... Getting appointments ...
$Appointments = $folder.Items
$Appointments.IncludeRecurrences = $true
$Appointments.Sort("[Start]")
echo ... Setting file names ...
$oldfile = "$env:USERPROFILE\outlook-calendar.bak"
echo oldfile: $oldfile
$newfile = "$env:USERPROFILE\outlook-calendar.txt"
echo newfile: $newfile
$calfile = "$env:USERPROFILE\outlook-calendar.ics"
echo calfile: $calfile
echo ... Exporting calendar to $calfile ...
$calendarSharing = $folder.GetCalendarExporter()
$calendarSharing.CalendarDetail = $olCalendarDetail::olFullDetails
$calendarSharing.IncludeWholeCalendar = $false
$calendarSharing.IncludeAttachments = $false
$calendarSharing.IncludePrivateDetails = $true
$calendarSharing.RestrictToWorkingHours = $false
$calendarSharing.StartDate = $now.AddDays(-30)
$calendarSharing.EndDate = $now.AddDays(30)
echo $calendarSharing
$calendarSharing.SaveAsICal($calfile)
echo ... Backing up $newfile into $oldfile ...
if (!(Test-Path $newfile)) {
echo "" |Out-File $newfile
}
# Backup old export into $oldfile
if (Test-Path $oldfile) {
echo "Deleting old backup file $oldfile"
del $oldfile
}
echo " ... moving $newfile into $oldfile ... "
move $newfile $oldfile
echo "... Generating text report to file $newfile ..."
$Appointments | Where-object { $_.start -gt $now -AND $_.start -lt $now.AddDays(+7) } |
Select-Object -Property Subject, Start, Duration, Location, IsRecurring, RecurrenceState |
Sort-object Start |
Out-File $newfile -Width 100
echo "... Comparing with previous export for changes ..."
$oldsize = (Get-Item $oldfile).length
$newsize = (Get-Item $newfile).length
if ($oldsize -ne $newsize ) {
echo "!!! Detected calendar change. Sending email..."
$mail = $outlook.CreateItem(0)
#2 = high importance email header
$mail.importance = 2
$mail.subject = $env:computername + “ Outlook Calendar“
$mail.Attachments.Add($newfile)
$mail.Attachments.Add($calfile)
$text = Get-Content $newfile | Out-String
$mail.body = “See attached file...“ + $text
#for multiple email, use semi-colon ; to separate
$mail.To = “your-email#your-mail-domain.com“
$mail.Send()
}
else {
echo "No changes detected in Calendar!"
}
} #end function Get-OutlookCalendar
Function Get-OutlookCalendarTest
{
echo starting...
Add-type -assembly "Microsoft.Office.Interop.Outlook" | out-null
$olFolders = "Microsoft.Office.Interop.Outlook.OlDefaultFolders" -as [type]
$outlook = new-object -comobject outlook.application
$namespace = $outlook.GetNameSpace("MAPI")
$folder = $namespace.getDefaultFolder($olFolders::olFolderCalendar)
$a = Get-Date -Hour 0 -Minute 00 -Second 00
$b = (Get-Date -Hour 0 -Minute 00 -Second 00).AddDays(7)
echo From $a To $b
$Appointments = $folder.Items
$Appointments.IncludeRecurrences = $true
$Appointments.Sort("[Start]")
$Appointments | Where-object { $_.start -gt $a -AND $_.start -lt $b } | Select-Object -Property IsRecurring, RecurrenceState, Subject, Start, Location
} #end function Get-OutlookCalendarTest
This is the code to invoke the PowerShell function in the module:
Path: Documents\WindowsPowerShell\mono.ps1
Import-Module -Name Outlook\expcal.psm1 -Force
$i=0
#infinite loop for calling connect function
while(1)
{
$i = $i +1
Write-Output "Running task Get-OutlookCalendar ($i)"
Get-OutlookCalendar
start-sleep -seconds 300
}
To run the PowerShell script, use powershell.exe. To run this on startup, a shortcut on "%APPDATA%\Microsoft\Windows\Start Menu\Programs\Startup\":
C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe -ExecutionPolicy Bypass "C:\Users\%USERNAME%\Documents\WindowsPowerShell\mono.ps1"

Related

Error Trapping of Redundant Event in 4 minute Window with PowerSell

I have a script that successfully traps an application event using a SQL query in the database. If found - it will write to the event log and sent an email to support team. Now the team wants to have a double check within a four minute window. You may get ErrorA & ErrorD twice - and ErrorB & ErrorC do not reoccur.
How would you do an internal check within the 1st loop. So first time you have ErrorA.1st and second check two minutes later you see ErrorA.1st = ErrorA.2nd, therefore send off a email?
while($true) ### Endless loop - continuely looking for ERRORS to trap for two actions below (Write event log and send email)
{
$connString = "data source=sqlservername,1433;Initial catalog=HugsDB;Integrated Security=True;"
$date= $((get-date).AddSeconds(-120).ToString("MM-dd-yyyy HH:mm:ss"))
$QueryText = "select statement that graps all errors $date"
#SETUP SQL VALUES####
$SqlConnection = new-object System.Data.SqlClient.SqlConnection
$SqlConnection.ConnectionString = $connString
$SqlCommand = $SqlConnection.CreateCommand()
$SqlCommand.CommandText = $QueryText
#### query the database
$DataAdapter = new-object System.Data.SqlClient.SqlDataAdapter $SqlCommand
$dataset = new-object System.Data.Dataset
$rowCount = $DataAdapter.Fill($dataset)
$sqlConnection.Close()
$sqlConnection.Dispose()
#### IF QUERY FINDS ERRORS # exact time of query ( could be 1 or more devices reporting an error ) write an event log message & send team an email
if($rowCount -gt 0) {
### assign a unique variable to each unique error on 1st find.
ForEach ($row in $dataset.Tables[0].Rows) {
[int]$incre = 0
$row.exciter_name = $incre.$row.exciter_name
}
## sleep 2 minutes before checking to see if we have a repeat of any of the finds in second query
Start-Sleep -Seconds 120
## Another query used to see if a reoccurance of same error.
## If the same error occurs send email and write error to event log.
if($rowCount -gt 0) {
ForEach ($row in $dataset.Tables[0].Rows) {
## NOT SURE HOW TO DO A CHECK TO LOOK FOR REOCCURANCE TO GENERATE EVENT.
write-Eventlog -LogName Exciter_Log -Source Exciter_Health –EventID 108 -Message "PACE Exciter Health Alert"
Send-MailMessage -smtpserver "$SMTPServer" -from "$EmailFrom" -to "$EmailTo" -subject "$Subject" -bodyAsHtml "$Body" -credential $anonCredentials
#################################################################################################################################################
#Second BREAK
Start-Sleep -Seconds 120
}
Sounds like you need to keep track of your previous message and compare them with the new messages. I'm assuming from the code that it does not matter which error message is actually repeated, but only that one is. In the example below what I've done is capture all unique messages in a variable called $currentErrors. Once done with capturing the messages you'll want to check if any of these previous errors appear in in this current set. If even one repeat error is found the the $alert flag is set to true and performs your error handling. Last it moves all current error messages into previous error message to be checked on the next run.
$currentErrors = #()
$alert = $false
if ($rowCount -gt 0)
{
foreach ($row in $dataset.Tables[0].Rows)
{
# not sure what these 2 lines do?
[int]$incre = 0
$row.exciter_name = $incre.$row.exciter_name
if ($currentErrors -notcontains $row.exciter_name) { $currentErrors += $row.exciter_name } # add error message to $currentErrors if not already added
}
# on first run previousErrors will be null so this foreach will do nothing
foreach ($error in $previousErrors)
{
if ($currentErrors -contains $error)
{
# previous error found in current errors
$alert = $true
break # exit loop once duplicate error is found
}
}
if ($alert)
{
Write-EventLog -LogName Exciter_Log -Source Exciter_Health –EventID 108 -Message "PACE Exciter Health Alert"
Send-MailMessage -smtpserver "$SMTPServer" -from "$EmailFrom" -to "$EmailTo" -subject "$Subject" -bodyAsHtml "$Body" -credential $anonCredentials
}
# move currentErrors into previousErrors for next loop
$previousErrors = $currentErrors
Start-Sleep -Seconds 120
}

Data inserting to ODBC destination with powershell

I need to load data table to ODBC driver connection with powershell.
With OLEDB and SQL server we can use Bulk Copy and insert data quickly.
Is there such posibility with ODBC ?
I'm using powershell because it shoud have the best support for these kind of opperations,
but my current code doesn't utillise an of the dlls.
So my code firstly needs to create an insert statements with two for loops and iterate on every row and hold it in its memory,
and then to construct INSERT INTO with 1000 rows, and then repeat same thing.
Am i doomed to something like this ?
$Datatable = New-Object System.Data.DataTable
$tabledump= $src_cmd.ExecuteReader()
$Datatable.Load($tabledump)
foreach ($item in $Datatable.Rows) {
$f +=1
for ($i = 0; $i -lt $item.ItemArray.Length; $i++) {
$items = $item[$i] -replace "'" , "''"
$val +="'"+ $items + "',"
}
$vals += $val
if ($f % 1000 -eq 0 -or $f -eq $row_cnt) {
$values = [system.String]::Join(" ", $vals)
$values = $values.TrimEnd(",")
$cols = [system.String]::Join(",", $columns)
$postgresCommand = "Insert Into $dst_schema.$dst_table ($cols) values $values"
$dest_cmd_.CommandText = $postgresCommand
$dest_cmd_.ExecuteNonQuery()
Bad code i admit, any advice on code compositions are welcomed.
You can use Get-ODBCDSN command to retrieve the values of the ODBC connections and use it with a query
$conn.ConnectionString= "DSN=$dsn;"
$cmd = new-object System.Data.Odbc.OdbcCommand($query,$conn)
$conn.open()
$cmd.ExecuteNonQuery()
$conn.close()
https://www.andersrodland.com/working-with-odbc-connections-in-powershell/
But the ODBC provider doesnt do bulk copy
https://learn.microsoft.com/en-us/sql/relational-databases/native-client-odbc-bulk-copy-operations/performing-bulk-copy-operations-odbc?view=sql-server-ver15
I know this post is not new, but i've been fiddeling around looking for a solution and also found nothing, however this post gave me a couple of insights.
First: There is no such thing as 'Bad Code'. If it works is not bad, heck even if it didn't worked, but helped with something..
Alright, what i did is not the best solution, but i'm trying to import Active Directory data on PostgreSQL, so...
I noticed that you're trying with pgsql as well, so you can use the COPY statement.
https://www.postgresql.org/docs/9.2/sql-copy.html
https://www.postgresqltutorial.com/import-csv-file-into-posgresql-table/
In my case i used it with a csv file:
*Assuming you have installed pgsql ODBC driver
$DBConn = New-Object System.Data.Odbc.OdbcConnection
$DBConnectionString = "Driver={PostgreSQL UNICODE(x64)};Server=$ServerInstance;Port=$Port;Database=$Database;Uid=$Username;Pwd=$(ConvertFrom-SecureString -SecureString $Password);"
$DBConn.ConnectionString = $DBConnectionString
try
{
$ADFObject = #()
$ADComputers = Get-ADComputer -Filter * -SearchBase "OU=Some,OU=OrgU,OU=On,DC=Domain,DC=com" -Properties Description,DistinguishedName,Enabled,LastLogonTimestamp,modifyTimestamp,Name,ObjectGUID | Select-Object Description,DistinguishedName,Enabled,LastLogonTimestamp,modifyTimestamp,Name,ObjectGUID
foreach ($ADComputer in $ADComputers) {
switch ($ADComputer.Enabled) {
$true {
$ADEnabled = 1
}
$false {
$ADEnabled = 0
}
}
$ADFObject += [PSCustomObject] #{
ADName = $ADComputer.Name
ADInsert_Time = Get-Date
ADEnabled = $ADEnabled
ADDistinguishedName = $ADComputer.DistinguishedName
ADObjectGUID = $ADComputer.ObjectGUID
ADLastLogonTimestamp = [datetime]::FromFileTime($ADComputer.LastLogonTimestamp)
ADModifyTimestamp = $ADComputer.modifyTimestamp
ADDescription = $ADComputer.Description
}
}
$ADFObject | Export-Csv $Env:TEMP\TempPsAd.csv -Delimiter ',' -NoTypeInformation
docker cp $Env:TEMP\TempPsAd.csv postgres_docker:/media/TempPsAd.csv
$DBConn.Open()
$DBCmd = $DBConn.CreateCommand()
$DBCmd.CommandText = #"
COPY AD_Devices (ADName,ADInsert_Time,ADEnabled,ADDistinguishedName,ADObjectGUID,ADLastLogonTimestamp,ADModifyTimestamp,ADDescription)
FROM '/media/TempPsAd.csv'
DELIMITER ','
CSV HEADER
"#
$DBCmd.ExecuteReader()
$DBConn.Close()
docker exec postgres_docker rm -rf /media/TempPsAd.csv
Remove-Item $Env:TEMP\TempPsAd.csv -Force
}
catch
{
Write-Error "$($_.Exception.Message)"
continue
}
Hope it helps!
Cheers!

write data into excel using powershell from sql table

I have a .xlsx file which was made into data table by oledb provider.Now I want to add value to that .xlsx based on the sql table data I have
(which is also converted into a csv file Book1.csv)
The sql table consists of name and notes...
Where name column is same in both .xlsx file and sql variable $sql
I want to add that close notes to f column of .xlsx file if the value of name matches with the value of sql table "A" column One I wrote below is very slow and not effective.
Any help would be highly appreciated.
$Excel = New-Object -ComObject Excel.Application
$Workbook = $Excel.Workbooks.Open('C:\Users\VIKRAM\Documents\Sample - Superstore.xlsx')
$workSheet = $Workbook.Sheets.Item(1)
$WorkSheet.Name
$Found = $WorkSheet.Cells.Find('$Data.number')
$Found.row
$Found.text
$Excel1 = New-Object -ComObject Excel.Application
$file = $Excel1.Workbooks.Open('C:\Users\VIKRAM\Documents\Book1.xlsx')
$ff=$file.Sheets.Item(1)
$ff.Name
$ff1=$ff.Range("A1").entirecolumn
$ff1.Value2
foreach ($line in $ff1.value2){
if( $found.text -eq $line)
{
Write-Host "success"
$fff=$ff1.Row
$WorkSheet.Cells.item($fff,20) =$ff.cells.item($fff,2)
}
}
Data in .xlsx file
Number Priority Comment
612721 4 - High
Data in Book1.csv
Number Clo_notes
612721 Order has been closed
I need to update clo_notes value to comment in .xlsx file if this "number" column in each file matches update the clos_notes to the corresponding column of comment
It looks like you answered my question about where "Nebraska" falls into the data.
Make sure to release any COM objects, or you'll have orphaned Excel processes.
You might try something like this. I was able to write the Clo_notes value into column 6 as you were requesting:
## function to close all com objects
function Release-Ref ($ref) {
([System.Runtime.InteropServices.Marshal]::ReleaseComObject([System.__ComObject]$ref) -gt 0)
[System.GC]::Collect()
[System.GC]::WaitForPendingFinalizers()
}
## open Excel data
$Excel = New-Object -ComObject Excel.Application
$Workbook = $Excel.Workbooks.Open('C:\Users\51290\Documents\_temp\StackOverflowAnswers\Excel.xlsx')
$workSheet = $Workbook.Sheets.Item(1)
$WorkSheet.Name
## open SQL data
$Excel1 = New-Object -ComObject Excel.Application
$file = $Excel1.Workbooks.Open('C:\Users\51290\Documents\_temp\StackOverflowAnswers\SQL.xlsx')
$sheetSQL = $file.Sheets.Item(1)
$dataSQL = $sheetSQL.Range("A1").currentregion
$foundNumber = 0
$row_idx = 1
foreach ($row in $WorkSheet.Rows) {
"row_idx = " + $row_idx
if ($row_idx -gt 1) {
$foundNumber = $row.Cells.Item(1,1).Value2
"foundNumber = " + $foundNumber
if ($foundNumber -eq "" -or $foundNumber -eq $null) {
Break
}
foreach ($cell in $dataSQL.Cells) {
if ($cell.Row -gt 1) {
if ($cell.Column -eq 1 -and $cell.Value2 -eq $foundNumber) {
$clo_notes = $sheetSQL.Cells.Item($cell.Row, 2).Value2
Write-Host "success"
$WorkSheet.Cells.item($row_idx, 6).Value2 = $clo_notes
}
}
}
}
$row_idx++
}
$Excel.Quit()
$Excel1.Quit()
## close all object references
Release-Ref($WorkSheet)
Release-Ref($WorkBook)
Release-Ref($Excel)
Release-Ref($Excel1)

PowerShell RoboCopy path issue

Objective: Robo copy from multiple machines on the network to a network share using variables for both the machine name and the currently logged on user.
What I have: txt file with a list of computernames.
Issue: I cannot get the foreach to work with the .split("\")[1] I use on the username variable to remove the domain prefix so I can use the output from that in the robocopy path
something like
robocopy "\\$computername\c$\documents and settings\$username\backup" "\\networkshare\backup\$username\backup"
gives me the error
You cannot call a method on a null-valued expression.
At C:\Scripts\Test\backup.ps1:13 char:2
Here's what I have so far. Can somebody help please?
function Get-LoggedIn {
[CmdletBinding()]
param (
[Parameter(Mandatory=$True)]
[string[]]$computername
)
foreach ($pc in $computername){
$logged_in = (gwmi win32_computersystem -COMPUTER $pc).username
$name = $logged_in.split("\")[1]
"{1}" -f $pc,$name
}
}
$computers = Get-Content "C:\Scripts\testcomputers.txt"
foreach ($computer in $computers) {
$users = Get-LoggedIn $computer
}
$SourceFolder = "\\$computer\c$\users\$users\desktop"
$DestinationFolder = "\\networkshare\backups\$users\backup\desktop"
$Logfile = "\\networkshare\backups\$users\backup\backuplog.txt"
Robocopy $SourceFolder $DestinationFolder /E /R:1 /W:1 /LOG:$Logfile
I see multiple errors here. You're not running the copy commands inside the foreach-loop. The username property recieved from WMI can often be in the following format:
domain\computer\username (or computer\domain\username, unsure since I'm on non-domain workstation now)
Anyways, the username is always the last part, so get it by using the index [-1] instead.
Updated script (with indents!):
function Get-LoggedIn {
[CmdletBinding()]
param (
[Parameter(Mandatory=$True)]
[string[]]$computername
)
foreach ($pc in $computername){
$logged_in = (gwmi win32_computersystem -COMPUTER $pc).username
$name = $logged_in.split("\")[-1]
"{1}" -f $pc,$name
}
}
$computers = Get-Content "C:\Scripts\testcomputers.txt"
foreach ($computer in $computers) {
$users = Get-LoggedIn $computer
$SourceFolder = "\\$computer\c$\users\$users\desktop"
$DestinationFolder = "\\networkshare\backups\$users\backup\desktop"
$Logfile = "\\networkshare\backups\$users\backup\backuplog.txt"
& Robocopy $SourceFolder $DestinationFolder /E /R:1 /W:1 /LOG:$Logfile
}

How to create a dynamic variable in Powershell, sucha as date/time etc

Hi i am not exactly sure if my wording is right but i need a variable which contains current date/time whenever i write data to log ; how can i do that without initializing everytime.Currently everytime i need a update i use these both statements jointly.Is there an other way of doing this?
$DateTime = get-date | select datetime
Add-Content $LogFile -Value "$DateTime.DateTime: XXXXX"
please do let me know if any questions or clarifications regarding my question.
This script make the real Dynamic variable in Powershell ( Thanks to Lee Holmes and his Windows PowerShell Cookbook The Complete Guide to Scripting Microsoft's Command Shell, 3rd Edition)
##############################################################################
##
## New-DynamicVariable
##
## From Windows PowerShell Cookbook (O'Reilly)
## by Lee Holmes (http://www.leeholmes.com/guide)
##
##############################################################################
<#
.SYNOPSIS
Creates a variable that supports scripted actions for its getter and setter
.EXAMPLE
PS > .\New-DynamicVariable GLOBAL:WindowTitle `
-Getter { $host.UI.RawUI.WindowTitle } `
-Setter { $host.UI.RawUI.WindowTitle = $args[0] }
PS > $windowTitle
Administrator: C:\Windows\System32\WindowsPowerShell\v1.0\powershell.exe
PS > $windowTitle = "Test"
PS > $windowTitle
Test
#>
param(
## The name for the dynamic variable
[Parameter(Mandatory = $true)]
$Name,
## The scriptblock to invoke when getting the value of the variable
[Parameter(Mandatory = $true)]
[ScriptBlock] $Getter,
## The scriptblock to invoke when setting the value of the variable
[ScriptBlock] $Setter
)
Set-StrictMode -Version 3
Add-Type #"
using System;
using System.Collections.ObjectModel;
using System.Management.Automation;
namespace Lee.Holmes
{
public class DynamicVariable : PSVariable
{
public DynamicVariable(
string name,
ScriptBlock scriptGetter,
ScriptBlock scriptSetter)
: base(name, null, ScopedItemOptions.AllScope)
{
getter = scriptGetter;
setter = scriptSetter;
}
private ScriptBlock getter;
private ScriptBlock setter;
public override object Value
{
get
{
if(getter != null)
{
Collection<PSObject> results = getter.Invoke();
if(results.Count == 1)
{
return results[0];
}
else
{
PSObject[] returnResults =
new PSObject[results.Count];
results.CopyTo(returnResults, 0);
return returnResults;
}
}
else { return null; }
}
set
{
if(setter != null) { setter.Invoke(value); }
}
}
}
}
"#
## If we've already defined the variable, remove it.
if(Test-Path variable:\$name)
{
Remove-Item variable:\$name -Force
}
## Set the new variable, along with its getter and setter.
$executioncontext.SessionState.PSVariable.Set(
(New-Object Lee.Holmes.DynamicVariable $name,$getter,$setter))
There's a Set-StrictMode -Version 3 but you can set it as -Version 2 if you can load framework 4.0 in your powershell V2.0 session as explained Here
The use for the OP is:
New-DynamicVariable -Name GLOBAL:now -Getter { (get-date).datetime }
Here the Lee Holmes's evaluation (where it is clear what is the real flaw) about the method I used in my other answer:
Note
There are innovative solutions on the Internet that use PowerShell's debugging facilities to create a breakpoint that changes a variable's value whenever you attempt to read from it. While unique, this solution causes PowerShell to think that any scripts that rely on the variable are in debugging mode. This, unfortunately, prevents PowerShell from enabling some important performance optimizations in those scripts.
Why not use:
Add-Content $LogFile -Value "$((Get-Date).DateTime): XXXXX"
This gets the current datetime every time. Notice that it's inside $( ) which makes powershell run the expression(get the datetime) before inserting it into the string.
wrap your two commands in function so you will have just one call ?
function add-log{
(param $txt)
$DateTime = get-date | select -expand datetime
Add-Content $LogFile -Value "$DateTime: $txt"
}
Besides these other ways (which frankly I would probably use instead - except the breakpoint approach), you can create a custom object with a ScriptProperty that you can provide the implementation for:
$obj = new-object pscustomobject
$obj | Add-Member ScriptProperty Now -Value { Get-Date }
$obj.now
Using PsBreakPoint:
$act= #'
$global:now = (get-date).datetime
'#
$global:sb = [scriptblock]::Create($act)
$now = Set-PSBreakpoint -Variable now -Mode Read -Action $global:sb
calling $now returns current updated datetime value
One liner:
$now = Set-PSBreakpoint -Variable now -Mode Read -Action { $global:now = (get-date).datetime }