create custom content type from schema.xml using csom and powershell

Question

I need to create a content type from my schema file which containe all my fields this is how to create a basic content type:

function  Add-metaXmlFields-ToContentType($ctx, $xmlFilePath, $CT_id)
{   
    $web = $ctx.Web
    $site = $ctx.Site
    $ctx.Load($web)
    $ctx.Load($site)

        try
        {
            $ctx.executeQuery()
            write-host "info: Loaded Fields and Content Types" -foregroundcolor green
        }
        catch{
            write-host "info: $($_.Exception.Message)" -foregroundcolor red
        }


        $ContentType = $ctx.web.contenttypes.getbyid($CT_id)


       [xml] $xmldata = [xml](Get-Content($xmlFilePath));
            if (-not $xmldata)
            {
                return
            }   
        Write-Host "Solutions xml file loaded successfully"



            foreach ($node in $xmldata.Elements.ChildNodes) {

                $field=$web.Fields.AddFieldAsXml($node.OuterXml,$true,[Microsoft.SharePoint.Client.AddFieldOptions]::AddFieldInternalNameHint); 
                # Finally, add the custom site column to our custom content typ$fieldReferenceLink = New-Object Microsoft.SharePoint.Client.FieldLinkCreationInformation

                $fieldReferenceLink = New-Object Microsoft.SharePoint.Client.FieldLinkCreationInformation
                $fieldReferenceLink.Field = $field;
                $ContentType.FieldLinks.Add($fieldReferenceLink)
            }

            # Commit changes to SharePoint
            $ContentType.Update($true)
            $ctx.ExecuteQuery()

        }

the probleme here is :

$node.OuterXml= 
<Field ID="{45FC08E4-15ED-4B99-BD0C-EAFC4C371D7A}" Name="Service Title" DisplayName="Service Title" Type="TaxonomyFieldType" Required="FALSE" Group="Custom Site Columns" xmlns="http://schema
s.microsoft.com/sharepoint/"></Field>

but :

$fieldReferenceLink.Field

AutoIndexed                 : 
CanBeDeleted                : 
DefaultValue                : 
Description                 : 
DescriptionResource         : Microsoft.SharePoint.Client.UserResource
Direction                   : 
EnforceUniqueValues         : 
EntityPropertyName          : 
Filterable                  : 
FromBaseType                : 
Group                       : 
Hidden                      : 
Id                          : 
Indexed                     : 
InternalName                : 
JSLink                      : 
ReadOnlyField               : 
Required                    : 
SchemaXml                   : 
SchemaXmlWithResourceTokens : 
Scope                       : 
Sealed                      : 
Sortable                    : 
StaticName                  : 
Title                       : 
TitleResource               : Microsoft.SharePoint.Client.UserResource
FieldTypeKind               : 
TypeAsString                : 
TypeDisplayName             : 
TypeShortDescription        : 
ValidationFormula           : 
ValidationMessage           : 
Context                     : Microsoft.SharePoint.Client.ClientContext
Tag                         : 
Path                        : Microsoft.SharePoint.Client.ObjectPathMethod
ObjectVersion               : 
ServerObjectIsNull          : 
TypedObject                 : Microsoft.SharePoint.Client.Field

it like no mapping there . any idea .

Answer 1

After a lot of investigation, it works now , only need : $context.Load() after every get context element ! this is the new version of the code :

$web = $ctx.Web
    $site = $ctx.Site
    $ctx.Load($web)
    $ctx.Load($site)
    $Fields=$ctx.web.Fields
    $ctx.Load($Fields)
        try
        {
            $ctx.executeQuery()
            write-host "info: Loaded Fields and Content Types" -foregroundcolor green
        }
        catch{
            write-host "info: $($_.Exception.Message)" -foregroundcolor red
        }


        $ContentType = $ctx.web.contenttypes.getbyid($CT_id)


       [xml] $xmldata = [xml](Get-Content($xmlFilePath));
            if (-not $xmldata)
            {
                return
            }   
        Write-Host "Solutions xml file loaded successfully"

             $ctx.Load($ContentType)
             $ctx.ExecuteQuery()

            foreach ($node in $xmldata.Elements.ChildNodes) {

                $field=$Fields.AddFieldAsXml($node.OuterXml,$true,[Microsoft.SharePoint.Client.AddFieldOptions]::AddFieldInternalNameHint);  
                # Finally, add the custom site column to our custom content typ$fieldReferenceLink = New-Object Microsoft.SharePoint.Client.FieldLinkCreationInformation

                $fieldReferenceLink = new-object Microsoft.SharePoint.Client.FieldLinkCreationInformation
                $fieldReferenceLink.Field = $field
            $addContentType = $ContentType.FieldLinks.Add($fieldReferenceLink)
            write-host "info: added $($node.OuterXml) to array" -foregroundcolor green
        } 

         $ContentType.Update($true)         
        # send the request containing all operations to the server
        try{
            $ctx.executeQuery()
            write-host "info: Added columns to content type" -foregroundcolor green
        }
        catch{
            write-host "info: $($_.Exception.Message)" -foregroundcolor red
        }

And this is my Fiel.xml:

<Elements xmlns="http://schemas.microsoft.com/sharepoint/">  
  <Field
       ID="{45FC08E4-15ED-4B99-BD0C-EAFC4C371D7A}"
       Name="a"
       DisplayName="a"
       Type="TaxonomyFieldType"
       Required="FALSE"
       Group="Custom Site Columns">
  </Field>

  <Field
      ID="{C574403E-6A2B-42D7-958E-017EF21D210E}"
      Name="b"
      DisplayName="b"
      Type="Note"
      Required="FALSE"
      Group="Custom Site Columns">
  </Field>
</Elements>

Hope it help.