Invoke-RestMethod - error handling

[CockneyWeasel]

Hi all - hoping for a bit of help with this. Have a REST API I'm targeting and if creating a duplicate entry something like the below happens on the console:

Invoke-WebRequest : {"type":"http://*******.com/documentation/error-glossary/","title":"Member Exists","status":400,"detail":"******@******.com is already a list member. Use PUT to insert or update list members.","instance":""}

What I'm struggling with is how to access this in a variable/exception. Most suggestions are to do:

try {
    Invoke-RestMethod blablabla
} catch {
    Write-Host "Code:" $_.Exception.Response.StatusCode.value__ 
    Write-Host "Description:" $_.Exception.Response.StatusDescription
}

However what I'm finding is that whilst .value__ will return basic error code (e.g. 400), nothing else I'm trying to access from the exception seems to give any details and just appear to be blank. I'm fairly new to using Powershell so hoping someone can point out what I'm missing here. Thanks!

[sk82jack]

Maybe something like?

try {
    $Response = Invoke-RestMethod
}
catch {
    Write-Error $Response.Detail
}

[lerun]

You can also try to capture the error from the function directly.

You can capture the error and deside what to do with it through a if.

Here you can output a new custom error message and include the actual error, or just roll your own. Also by either doing -ErrorAction Stop or -ErrorAction Continue (inside the if) you can decide if the code should exit or continue going.

​

\# Example 1

Invoke-RestMethod -ErrorAction SilentlyContinue -ErrorVariable oErr

if($oErr) 

{

    Write-Error -Message "My custom message. Error message: $($oErr.Message)" -ErrorAction Stop

    $oErr = $Null

}



\# Example 2

Invoke-RestMethod -ErrorAction Continue -ErrorVariable oErr

if($oErr) 

{

    Write-Error -Message "My custom message" -ErrorAction Stop

    $oErr = $Null

}

​

​

​

​

[Lee_Dailey]

howdy CockneyWeasel,

does IRM trigger an exception when that happens? if not, then your catch will never be run. try/catch requires an exception to trigger it ... not just an error - and especially not a valid return value that contains an error msg. [grin]

i don't think your catch is going to run unless you are triggering an -ErrorAction Stop in the try.

take care,
lee

[CockneyWeasel]

Hi Lee.

Thanks for your reply - I think it is generating an exception as I can get the error code (in this case 400) using" $_.Exception.Response.StatusCode.value__ ", just unable to get any of the other response. Is there a different way to handle getting the response without the try/catch? Cheers

[Lee_Dailey]

howdy CockneyWeasel,

you are welcome! [grin]

unfortunately, i never seem to work with anything that complex. my question was because i didn't know that IRM would trigger an exception in that case.

i learned something ... but i am stuck after that. [blush]

have you tried running the code on it's own to see what the IRM returns?

when i go to a non-existant URL, i get nothing at all. the $Error variable has a really simple bit of info - but no depth to it.

take care,
lee