Src/Private/PSGraph/Edge.ps1
|
function Edge { <# .Description This defines an edge between two or more nodes .Example Graph g { Edge FirstNode SecondNode } Generates this graph syntax: digraph g { "FirstNode"->"SecondNode" } .Example $folder = Get-ChildItem -Recurse -Directory graph g { $folder | %{ edge $_.parent $_.name } } # with parameter names specified graph g { $folder | %{ edge -From $_.parent -To $_.name } } # with scripted properties graph g { edge $folder -FromScript {$_.parent} -ToScript {$_.name} } .Example graph g { edge (1..3) (5..7) edge top bottom @{label="line label"} edge (10..13) edge one,two,three,four } .Notes If an array is specified for the From property, but not for the To property, then the From list will be procesed in order and will map the array in a chain. #> [cmdletbinding( DefaultParameterSetName = 'Node' )] param( # start node or source of edge [Parameter( Mandatory = $true, Position = 0, ParameterSetName = 'Node' )] [Parameter( Mandatory = $true, Position = 0, ParameterSetName = 'Attributes' )] [alias( 'NodeName', 'Name', 'SourceName', 'LeftHandSide', 'lhs' )] [string[]] $From, # Destination node or target of edge [Parameter( Mandatory = $false, Position = 1, ParameterSetName = 'Node' )] [alias('Destination', 'TargetName', 'RightHandSide', 'rhs')] [string[]] $To, # Hashtable that gets translated to an edge modifier [Parameter( Mandatory = $true, Position = 1, ParameterSetName = 'Attributes' )] [Parameter( Position = 2, ParameterSetName = 'Node' )] [Parameter( Position = 1, ParameterSetName = 'script' )] [hashtable] $Attributes = @{}, # a list of nodes to process [Parameter( Mandatory = $true, Position = 0, ValueFromPipeline = $true, ParameterSetName = 'script' )] [Alias('InputObject')] [Object[]] $Node, # start node script or source of edge [Parameter( ParameterSetName = 'script')] [alias('FromScriptBlock', 'SourceScript')] [scriptblock] $FromScript = {$_}, # Destination node script or target of edge [Parameter(ParameterSetName = 'script')] [alias('ToScriptBlock', 'TargetScript')] [scriptblock] $ToScript = {$null}, # A string for using native attribute syntax [string] $LiteralAttribute = $null, # Not used, but can be specified for verbosity [switch] $Default ) begin { if ( -Not [string]::IsNullOrEmpty($LiteralAttribute) ) { $GraphVizAttribute = $LiteralAttribute } } process { try { if ( $Node.count -eq 1 -and $node[0] -is [Hashtable] -and !$PSBoundParameters.ContainsKey('FromScript') -and !$PSBoundParameters.ContainsKey('ToScript') ) { #Deducing the pattern 'edge @{}' as default edge definition $GraphVizAttribute = ConvertTo-GraphVizAttribute -Attributes $Node[0] '{0}edge {1}' -f (Get-Indent), $GraphVizAttribute } elseif ( $null -ne $Node ) { # Used when scripted properties are specified foreach ( $item in $Node ) { $fromValue = ( @($item).ForEach($FromScript) ) $toValue = ( @($item).ForEach($ToScript) ) $LiteralAttribute = ConvertTo-GraphVizAttribute -Attributes $Attributes -InputObject $item -From $fromValue -To $toValue edge -From $fromValue -To $toValue -LiteralAttribute $LiteralAttribute } } else { if ( $null -ne $To ) { # If we have a target array, cross multiply results foreach ( $sNode in $From ) { foreach ( $tNode in $To ) { if ( [string]::IsNullOrEmpty( $LiteralAttribute ) ) { $GraphVizAttribute = ConvertTo-GraphVizAttribute -Attributes $Attributes -From $sNode -To $tNode } if ($GraphVizAttribute -match 'ltail=' -or $GraphVizAttribute -match 'lhead=') { # our subgraph to subgraph edges can crash the layout engine # adding invisible edge for layout hints helps resolve this Edge -From $sNode -To $tNode -LiteralAttribute '[style=invis]' } '{0}{1}->{2} {3}' -f (Get-Indent), (Format-Value $sNode -Edge), (Format-Value $tNode -Edge), $GraphVizAttribute } } } else { # If we have a single array, connect them sequentially. for ( $index = 0; $index -lt ( $From.Count - 1 ); $index++ ) { if ([string]::IsNullOrEmpty( $LiteralAttribute ) ) { $GraphVizAttribute = ConvertTo-GraphVizAttribute -Attributes $Attributes -From $From[$index] -To $From[$index + 1] } ('{0}{1}->{2} {3}' -f (Get-Indent), (Format-Value $From[$index] -Edge), (Format-Value $From[$index + 1] -Edge), $GraphVizAttribute ) } } } } catch { $PSCmdlet.ThrowTerminatingError( $PSitem ) } } } |