How to create JSON payload using power shell Foreach loop - json

Question

Requirement: To send E-Mail via send grid account (Send Grid API) by attaching multiple attachments.
Description: I am able to create json payload and able to send with single attachment by hard coding attachment values. I am opening window forms dialog and able to select single/multiple files that needs to be attached.
Code:
$FileBrowser = New-Object System.Windows.Forms.OpenFileDialog -Property #{
InitialDirectory = [Environment]::GetFolderPath('Desktop')
#Filter = 'Documents (*.docx)|*.docx|SpreadSheet (*.xlsx)|*.xlsx'
Filter = 'All files (*.*)| *.*'
Title = 'Select File(s) for Attachments'
Multiselect = $true
}
$FileBrowser.ShowDialog() | Out-Null
$FilesEncodedContents = New-Object System.Collections.ArrayList
$AttachmentsjsonRequest = #()
if ($FileBrowser.FileNames.Count -gt 0) {
foreach ($file in $FileBrowser.FileNames) {
[string] $filerawContent = $null
$filedetails = Get-Item $file
$filerawContent = ConvertToBase64Encode $file
if (![string]::IsNullOrWhitespace($filerawContent)) {
$FilesEncodedContents.Add($filerawContent)
$obj = New-Object -TypeName PSObject
$obj | Add-Member -MemberType NoteProperty -Name filename -Value (Get-Item $file).Name
$obj | Add-Member -MemberType NoteProperty -Name content_id -Value (Get-Item $file).Name
$obj | Add-Member -MemberType NoteProperty -Name content -Value $filerawContent
$obj | Add-Member -MemberType NoteProperty -Name disposition -Value 'attachment'
$AttachmentsjsonRequest += $obj
}
}
}
Write-Host "$AttachmentsjsonRequest"
$headers = #{ }
$headers.Add("Authorization", "Bearer $ApiKey")
$headers.Add("Content-Type", "application/json")
$jsonRequest = [ordered]#{
personalizations = #(#{to = #(#{email = "$MailTo" })
subject = "$Subject"
})
from = #{email = "no-reply#xxx.com" }
attachments = "$AttachmentsjsonRequest"
content = #( #{ type = "text/plain"
value = "Sample Mail Body"
}
)
} | ConvertTo-Json -Depth 100
Write-Host $jsonRequest | ConvertTo-Json -Depth 100
Invoke-RestMethod -Uri "https://api.sendgrid.com/v3/mail/send" -Method Post -Headers
$headers -Body $jsonRequest
Write-Host "Mail Sent"
#region ConvertToBase64Encode
Function ConvertToBase64Encode([string] $AttachementFile) {
[string] $fileContentEncoded = $null
if (Test-Path $AttachementFile -PathType leaf) {
$fileContent = get-content $AttachementFile
$fileContentBytes = [System.Text.Encoding]::UTF8.GetBytes($fileContent)
$fileContentEncoded = [System.Convert]::ToBase64String($fileContentBytes)
$fileContentEncoded | set-content ((Get-Item -Path $AttachementFile).Name + ".b64")
}
else {
$fileContentEncoded = $null
Write-Host "File : $FileAttachment not exists,skipping and continue to add if any other
attachments uploaded"
}
return $fileContentEncoded
}
#endregion
Problem: [UPDATED]
Am getting below error after trying to upload single or multiple attachments
{"errors":[{"message":"Invalid type. Expected: array, given: string.","field":"attachments","help":"http://sendgrid.com/docs/API_Reference/Web_API_v3/Mail/errors.html#message.attachments"}]} .
Reference Links :
Send Grid API Documentation:
https://sendgrid.com/docs/API_Reference/api_v3.html

Answer 1

My advice is to consider not building the JSON as a text, first build a Powshell object that you convert to JSON with ConvertTo-Json.
Using this method, arrays will be correctly represented in JSON. don't forget to set the -DEPTH param.
attachments array[object] An array of objects in which you can specify any attachments you want to include.
So in your Powershell object attachments is going to be a #().
of objects with content, type, filename, disposition, conten_id properties.

Answer 2

I realized error details in depth in late . It was giving hint in JSON payload "attachments" field is showing as string rather than array object which it is fixed by adding #(#()) to attachmentjsonrequest in "$jsonrequest" variable .
In Short: "attachmentjsonrequest is an array object which needs to convert to JSON payload by using #()
Thanks for suggesting to use array object.
attachments = #(#($AttachmentsjsonRequest))