Load-Assemblies.ps1

# Copyright 2016 Cloudbase Solutions Srl
#
# Licensed under the Apache License, Version 2.0 (the "License"); you may
# not use this file except in compliance with the License. You may obtain
# a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
# WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
# License for the specific language governing permissions and limitations
# under the License.
#

$here = Split-Path -Parent $MyInvocation.MyCommand.Path

function Load-Assembly {
    $libDir = Join-Path $here "lib"
    $assemblies = @{
        "core" = Join-Path $libDir "netstandard2.1\YamlDotNet.dll";
        "net45" = Join-Path $libDir "net45\YamlDotNet.dll";
        "net35" = Join-Path $libDir "net35\YamlDotNet.dll";
    }

    if ($PSVersionTable.Keys -contains "PSEdition") {
        if ($PSVersionTable.PSEdition -eq "Core") {
            return [Reflection.Assembly]::LoadFrom($assemblies["core"])
        } elseif ($PSVersionTable.PSVersion.Major -ge 4) {
            return [Reflection.Assembly]::LoadFrom($assemblies["net45"])
        } else {
            return [Reflection.Assembly]::LoadFrom($assemblies["net35"])
        }
    } else { # Powershell 4.0 and lower do not know "PSEdition" yet
        return [Reflection.Assembly]::LoadFrom($assemblies["net35"])
    }
}


function Initialize-Assemblies {
    $requiredTypes = @(
        "Parser", "MergingParser", "YamlStream",
        "YamlMappingNode", "YamlSequenceNode",
        "YamlScalarNode", "ChainedEventEmitter",
        "Serializer", "Deserializer", "SerializerBuilder",
        "StaticTypeResolver"
    )

    $type = "YamlDotNet.Serialization.Serializer" -as [type]
    if (!$type) {
        return Load-Assembly
    }

    $yaml = $type.Assembly
    foreach ($i in $requiredTypes){
        if ($i -notin $yaml.DefinedTypes.Name) {
            Throw "YamlDotNet is loaded but missing required types ($i). Older version installed on system?"
        }
    }
}

Initialize-Assemblies | Out-Null