Create a dynamic ReST request body in PowerShell - rest

Question

I am currently working on a use case for invoking ReST request in PowerShell. The body of POST request is created dynamically, reading data from a CSV file.
Here is how my final request body should be
{
"#type": "mtTaskParameter",
"name": "$src_sfdc$",
"type": "EXTENDED_SOURCE",
"sourceConnectionId":"00002E0B00000000000C"
},
{
"#type": "mtTaskParameter",
"name": "$tgt_db_del$",
"type": "TARGET",
"targetConnectionId":"00002E0B00000000000D"
},
{
"#type": "mtTaskParameter",
"name": "$tgt_db_ups$",
"type": "TARGET",
"targetConnectionId":"00002E0B00000000000D"
},
{
"#type": "mtTaskParameter",
"name": "$tgt_status$",
"type": "TARGET",
"targetConnectionId":"00002E0B00000000000D"
}
}
Currently I have implemented like below
if($connectionParameterized -eq "true"){
$str = #"
"#type": "mtTaskParameter",
"name": "$name",
"type": "$type"
"#
if($type -eq "SOURCE"){
$sourceConnectionId = <get source id>
$str = $str+
#"
,"sourceConnectionId":"$sourceConnectionId"
"#
}
if($type -eq "TARGET"){
$targetConnectionId = <get target id>
$str = $str+
#"
,"targetConnectionId":"$targetConnectionId"
"#
}
$finalstr = $finalstr+#"
{
$str
},
"#
}
This works fine, but the code becomes really messy and so difficult to scale. Also while printing, the format is not proper.
Is there a better way to handle this?
Note: As evident from the example, the request body contains several special characters like #,$ etc.

Answer 1

This would be easier if you included your CSV, but basically, you can import the CSV as an array of objects, then convert that to JSON.
You can customize the objects that are created from importing the CSV by adding custom members so that the translation to JSON gives you the output you want.
You can also group or filter the array of objects to make different ones depending on certain conditions.
Here's a some sample code that probably won't work directly but should somewhat demonstrate the concept:
$json = Import-Csv -Path C:\my\data.csv |
ForEach-Object -Process {
$row = $_
$propName = $row.Type.ToLower() + 'ConnectionId'
$row | Add-Member -NotePropertyName $propName -NotePropertyValue $out["$mapping_name"].$name -Force -PassThru
} |
ConvertTo-Json