Send an array in Get rest message header in Powershell

Question

I'm trying to send an array of numbers in a rest message header to Servicenow, but I'm not having any luck getting a good response back. If I hard code the numbers into the header instead of using an array variable I get the information I'm looking for, but I need to be able to pass the array which is generated from a previous step.

In the header you can see where I'm trying to send a "ritm" header. If I send the line that's commented out it will work, but the line with the array variable listed does not work. Here's what I have:

$headers = @{
  Authorization=("Basic {0}" -f $base64AuthInfo)
  Accept = "application/json"
  #ritm = "REQITEM0096138,REQITEM0096137"  ## If I send this line it works
  ritm = $reqitems
}

# Specify endpoint uri
$uri = "https://service-now.com/api/"

# Specify HTTP method
$method = "get"

# Send HTTP request
$response = Invoke-RestMethod -Headers $headers -Method $method -Uri $uri
$response.result | fl

briantist · Accepted Answer · 2016-10-18 16:49:47Z

1

The default serialization of an array to a [string] is to separate each element with spaces. If you need a different separator, use the -join operator:

$headers = @{
    ritm = $reqitems -join ','
}

answered Oct 18, 2016 at 16:49

briantist

48.3k6 gold badges94 silver badges139 bronze badges

Sign up to request clarification or add additional context in comments.

8 Comments

tlock Over a year ago

I should have added that I already have the $reqitems array comma separated.

briantist Over a year ago

@tlock arrays don't have separators. Do you have an [array], or a [string]? If you run gm -i $reqitems what type is shown at the top?

tlock Over a year ago

TypeName: System.Object[]

briantist Over a year ago

@tlock so it is an array. By using -join you will create a string where each item in the array is separated by the string you give it. When you define an array using commas, you are just telling the parser that you want to create an array. The commas don't become part of the content.

tlock Over a year ago

So i created the array variable with this code: $reqitems = @() and then I'm adding items to it with $reqitems +=

|

Jim Moyle · Accepted Answer · 2016-10-18 17:18:59Z

0

REST headers in powershell don't automatically convert nested objects to the correct format, so you'll need to create a string rather than an array.

Your ritm = $reqitems is probably created using

$reqitems = 'blah', 'blah2'

This creates an array which the header doesn't like

If you don't want an array you can do

$reqitems = 'blah1, blah2'

This will create your values as a string, which will work better.

edited Oct 18, 2016 at 17:18

answered Oct 18, 2016 at 17:08

Jim Moyle

6754 silver badges12 bronze badges

2 Comments

briantist Over a year ago

I would discourage creating the string directly that way. Besides the fact that it's not quite that straightforward when your items are not defined as design time, it can lead to errors, and it needs extra conditionals to handle the first/last item so you don't end up with an extra comma. This is the situation -join was made for. Personally I will often create an array and join it even if I'm statically defining the items, as it tends to be clearer and easier to edit.

Jim Moyle Over a year ago

Yep if I'm changing or adding to a string I'd agree and do an array then convert using join, but that wasn't clear from the original post. I don't mind the string method if it's only 1 or 2 items and you can make sure it's clear.

Collectives™ on Stack Overflow

Send an array in Get rest message header in Powershell

2 Answers 2

8 Comments

2 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

8 Comments

2 Comments

Your Answer

Sign up or log in

Post as a guest

Related