An Even Better PowerShell Forecast

Published on Monday, October 13, 2014

Photo by Jan Loyde Cabrera on Unsplash

After posting the last update to my PowerShell weather script, I was looking at the sheer awkwardness of the pre-made SOAP request. Basically, in order to send a SOAP request to the web service, I just kept a ready-made SOAP envelope in a file alongside the script, prepped it with some simple search-and-replace for the parameters, and used Invoke-WebRequest to POST it. Here's the old code:

$uri = ""
$lat = "40.019444"
$lon = "-105.292778"
$start =  Get-Date -format "yyyy-MM-dd"

$body = Get-Content .\ndfd.soap
$body = $body.Replace("[lat]", $lat).Replace("[lon]", $lon).Replace("[start]", $start)

[xml]$envelope = Invoke-WebRequest $uri -Method post -ContentType "text/xml" -Body $body
[xml]$weather = $envelope.Envelope.Body.NDFDgenByDayResponse.dwmlByDayOut.'#text'

It's awkward and very lazy, but it works. Still, it was bothering me. After a little more research, it turns out that if you've got a WSDL, you can just generate a proxy straight out of PowerShell (much the same way you'd generate proxy classes to work with a SOAP service from Visual Studio). The cmdlet you need is New-WebServiceProxy (naturally). Here's the updated code using New-WebServiceProxy and dumping the pre-made SOAP request:

$uri = ""
$lat = "40.0269"
$lon = "-105.251"Po
$start =  Get-Date -format "yyyy-MM-dd"

$Proxy = New-WebServiceProxy -uri $URI -namespace WebServiceProxy

[xml]$weather = $Proxy.NDFDgenByDay($lat, $lon, $start, 7, "e", "Item24hourly")

Just generate the proxy and call the method. Notice that this also means I get to drop the awkward line of code which extracted the XML I cared about from the return SOAP envelope. Much cleaner.