PowerShell, is a Microsoft download, currently at version 4.0. It is a batch command language and enhanced command shell which is the current successor to the CMD.exe found in Windows. It seems to be a bit of a mash-up between the old DOS command line, the Unix-style shells like BASH, and includes connections to .NET objects. Unfortunately, it also abstracts a number of parameters to objects, such that you can’t just put stuff on a command line; you have to assign it to an object parameter when passing parameters, or when getting things out from a returned object.
To continue with our Brightpearl example:
Recall that when working with the Brighpearl API, you have to first obtain a temporary authorization code, which is good for roughly 30 minutes. You do this by making an HTTP POST which includes your credentials in the body of the post.
Obtain a Brightpearl Authorization Code:
This is a two step process:
1. First stuff the authorization credentials into a variable. Note that the credentials are formatted in nested JSON notation.
$bpauth = “{apiAccountCredtentials:{emailAddress:”myemail@mycompany.com”, password:”Mypassword”}}”
2. Execute the command line call using the stored log-in credentials in the Body parameter
http://ws-use.brightpearl.com/mybpaccountname/authorise -Body $bpauth -ContentType application/json -Method Post
The Brightpearl server returns an authorization code which is displayed as an object with a series of parameters. The authorization code is contained in the a JSON string in the “Content” parameter. This is the authorization code that must accompany any subsequent call to the Brightpearl API.
StatusCode : 200
StatusDescription : OK
Content : {“response”:”53145c429-x1xx-y2sf-z34a-8abc9cde96f9gh”}
RawContent : HTTP/1.1 200 OK
Pragma: no-cache
ruid: a745efb3-2414-428f-8427-5001e3c810b8
Connection: keep-alive
Content-Length: 51
Cache-Control: no-cache, must-revalidate
Content-Type: application/json;char…
Forms : {}
Headers : {[Pragma, no-cache], [ruid, a745efb3-2414-428f-8427-5001e3c810b8], [Connection, keep-alive], [Content-Length, 51]…}
Images : {}
InputFields : {}
Links : {}
ParsedHtml : mshtml.HTMLDocumentClass
RawContentLength : 51
To isolate the code itself, you have to assign the output of the above command to a variable, and then access it using dot notation.
So, restate the above command to assign the output to a variable:
$bpcode = Invoke-WebRequest -Uri http://ws-use.brightpearl/microdesign/authorize -Body $bpauth -ContentType application/json – Method Post
If you then execute $bpcode.Content, then you’ll get the authorization code, (again in JSON format).
PS C:UsersLarryPowerShell>$bpcode.Content
This returns:
{“response”:”53145c429-x1xx-y2sf-z34a-8abc9cde96f9gh”}
To see this in a more readable format:
PS C:UsersLarryPowerShell>$bpcode.Content | ConvertFrom-Json
response
——–
53145c429-x1xx-y2sf-z34a-8abc9cde96f9gh
To assign the authorization code to a variable itself, we either have to strip it from the JSON code, or from the returned converted version. It probably is easier to convert via the JSON code because we can do a text search everything after the colon, and then strip off the double quotes and the last curly bracket.
$bpstring=$bpcode.content
The following command strips off everything up to the start of the actual code.
$bpstring = $bpstring. Trimstart( “{`”response`”`:” )
It gives us:
“53145c429-x1xx-y2sf-z34a-8abc9cde96f9gh”}
The following command strips off the final quote and curly bracket.
$bpstring = $bpstring. Trimend( “`”`}”)
This gives us our final result; what we’re really looking for:
53145c429-x1xx-y2sf-z34a-8abc9cde96f9gh
Final Script:
The final script is pretty close to the interactive commands entered at the PowerShell command line. The main exception is the addition of the back tick escape character within the script. If you use the PowerShell Interactive Shell as an editor, it will color code things nicely and flag scripting errors.
# BrightPearl API: Get an authorization code for subsequent API queries
# Note escape character is the “`” (back tick), instead of the usual backslash.
# Double quotes need to be escaped when nested inside.
# LK 10/9/2014
# Assign credentials to an authorization object.
$bpauth = “{apiAccountCredentials:{emailAddress:`”myeMailAddress@mycompany.com`”,password:`”myPassword`”}}”
# Execute the HTTP POST to retrieve the authorization code. The result is assigned to the string $bpstring
# Note use of the back tick as a line continuation character
$bpstring = Invoke-WebRequest `
-Body $bpauth `
-ContentType application/json `
-Method Post
$bpAuthCode =$bpstring . Content
$bpAuthCode =$bpAuthCode . Trimstart( “{`”response`”`:” )
$bpAuthCode =$bpAuthCode . TrimEnd( “`”`}” ) #Note escape codes for the search expression
# Print the Authorization Code
$bpAuthCode
tfnp 