Find variables within a string in PowerShell - powershell

Question

I've a sample code like this:
[string] $Text = "This is a string text with some $($variable.Option) and $otherOption and that's it".
Now what I would like to know is it possible to split that $Text into standard strings and variables separately? So that when I pass this $Text variable to a method it's able to extract $($variable.Option) separately?
I know it's a long shot but maybe it's not being processed right away at assignment time?
The ultimate goal is to create a better version of method I wrote for making colorful powershell:
function Write-Color([String[]]$Text, [ConsoleColor[]]$Color = "White", [int]$StartTab = 0, [int] $LinesBefore = 0,[int] $LinesAfter = 0) {
$DefaultColor = $Color[0]
if ($LinesBefore -ne 0) { for ($i = 0; $i -lt $LinesBefore; $i++) { Write-Host "`n" -NoNewline } } # Add empty line before
if ($StartTab -ne 0) { for ($i = 0; $i -lt $StartTab; $i++) { Write-Host "`t" -NoNewLine } } # Add TABS before text
if ($Color.Count -ge $Text.Count) {
for ($i = 0; $i -lt $Text.Length; $i++) { Write-Host $Text[$i] -ForegroundColor $Color[$i] -NoNewLine }
} else {
for ($i = 0; $i -lt $Color.Length ; $i++) { Write-Host $Text[$i] -ForegroundColor $Color[$i] -NoNewLine }
for ($i = $Color.Length; $i -lt $Text.Length; $i++) { Write-Host $Text[$i] -ForegroundColor $DefaultColor -NoNewLine }
}
Write-Host
if ($LinesAfter -ne 0) { for ($i = 0; $i -lt $LinesAfter; $i++) { Write-Host "`n" } } # Add empty line after
}
Usually I can assign colors by doing something like
write-color -Text "[View][$($singleView.Title)]",
"[Row Limit: $($singleView.RowLimit)]",
"[Paged: $($singleView.Paged)]",
"[Default View: $($singleView.DefaultView)]",
"[Style ID: $($singleView.StyleID)]" -Color Yellow, Green, Red, Gray, Green
But this means I get colors for the whole "line". If i would like to get normal text colors in one color and variables being in second color I would have to do something like this:
write-color -Text "[View: ", "$($singleView.Title)", "]",
"[Row Limit: ", "$($singleView.RowLimit)", "]" `
-Color Yellow, Green, Yellow, Yellow, Green, Yellow
It's not bad.. but I just thought if this can be accomplished in a better way where simple text is one color and variables are the 2nd. If I would want to go even further and have $true being in Green and False being in Red that would also require some parsing.

Answer 1

Variables will expand inside double quotes. Once that is done there is no history to speak of.
You have one of two options here. You can use the format operator to send in string with placeholders for your variables.
Use the format operator
ss64 on Using the format operator
# Create a formatted string with variable placeholders
$Text = "This is a string text with some {0} and {1} and that's it"
# Pass that string into a function and put in the variables
$stringParameterinFunction -f $variable.Option, $otherOption
String Expansion
If you really wanted what I think you are asking for then you can delay the string expansion by use single quotes on the original string. Note the single quote inside the string was escaped.
$Text = 'This is a string text with some $($variable.Option) and $otherOption and that''s it.'
# Pass that string into a function and put in the variables
$ExecutionContext.InvokeCommand.ExpandString($stringParameterinFunction)