Category: Programming

I have been staffing at Sakura-Con Guest Relations since 2002, and throughout years, I have been experimenting with numerous technologies to support event planning. Previously, I have used Org-mode, some small Python scripts, and this year, I have been constructing the system using PowerShell Core. I have been using PowerShell to various applications, like tabulating Karaoke data, I wanted to expand the use cases for this area as well.

Motivations

My goal for this year to build a centralize solution to:

• Provide the automated way of tabulating event schedule data and create a data set that I can work with.
• Provide conversion from the event schedule data to other useful data type, such as calendar format.

The reason I have picked PowerShell Core is:

• I wanted the solution that works across multiple platforms. I use Linux and Windows. Big plus if it runs on Android. What makes this great is that PowerShell Core can run on Android environment through app like UserLAnd. (If you are doing this on Android, the keyboard such as this one helps a lot.)
• I wanted something that I can use offline. During the event, internet connection may be degraded to the point it’s unusable.

Components and Setup

First module I have created, is a data fetcher to retrieve schedule data from the scheduling system. The scheduling system, unfortunately lacked API that allowed me to retrieve the data from the system, and I used Selenium to retrieve the data.

Obtaining data through Selenium would take about 30 seconds — there are about 800 entries. (though, I regularly interact about 1/8 of it.) The Selenium module navigates to the appropriate calendar ranges through UI, and grabs the result out from the DOM. This is coded in C#. Since Selenium provides driver for both Linux and Windows, same module works works cross-platform as well. (Probably not on Android, but if there’s a driver for Android, this potentially can be done on Android as well.)

The system exposes the following data, and is exported as array:

   TypeName: SakuraCon.Relations.Data.Event
Name        MemberType     Definition
----        ----------     ----------
End Time    AliasProperty  End Time = EndTime
Event Title AliasProperty  Event Title = EventTitle
Start Time  AliasProperty  Start Time = StartTime
Equals      Method         bool Equals(System.Object obj)
GetHashCode Method         int GetHashCode()
GetType     Method         type GetType()
ToString    Method         string ToString()
EndTime     Property       datetime EndTime {get;set;}
EventId     Property       string EventId {get;set;}
EventTitle  Property       string EventTitle {get;set;}
Notes       Property       string Notes {get;set;}
Rating      Property       string Rating {get;set;}
StartTime   Property       datetime StartTime {get;set;}
Type        Property       string Type {get;set;}
Venue       Property       string Venue {get;set;}
Duration    ScriptProperty System.Object Duration {get=($this.EndTime - $this.StartTime);}

This is coupled with the simple ps1xml:

<Types>
    <Type>
        <Name>SakuraCon.Relations.Data.Event</Name>
        <Members>
            <MemberSet>
                <Name>PSStandardMembers</Name>
                <Members>
                    <PropertySet>
                        <Name>DefaultDisplayPropertySet</Name>
                        <ReferencedProperties>
                            <Name>Event Title</Name>
                            <Name>Venue</Name>
                            <Name>Type</Name>
                            <Name>Start Time</Name>
                            <Name>End Time</Name>
                            <Name>Duration</Name>
                            <Name>Notes</Name>
                        </ReferencedProperties>
                    </PropertySet>
                </Members>
            </MemberSet>
            <AliasProperty>
                <Name>Event Title</Name>
                <ReferencedMemberName>EventTitle</ReferencedMemberName>
            </AliasProperty>
            <AliasProperty>
                <Name>Start Time</Name>
                <ReferencedMemberName>StartTime</ReferencedMemberName>
            </AliasProperty>
            <AliasProperty>
                <Name>End Time</Name>
                <ReferencedMemberName>EndTime</ReferencedMemberName>
            </AliasProperty>
            <ScriptProperty>
                <Name>Duration</Name>
                <GetScriptBlock>($this.EndTime - $this.StartTime)</GetScriptBlock>
            </ScriptProperty>
        </Members>
    </Type>
</Types>

Usually, I export this data into clixml — this way, I can retrieve the contents later as needed. PowerShell provides the convenient cmdlet to do this.

$schedule | Export-Clixml schedule.xml

Importing this is easy:

$schedule = Import-Clixml schedule.xml

This would allow offline access to the data offline, as exported XML is essentially the snapshot of obtained data.

From this, I can easier export this as CSV (used for tabulating schedule information) and as a iCalendar format that can be imported into Google Calendar.

Something I like about this data structure is that I can use Where-Object to retrieve desired information. If I want all the event that happens in the room 6C, I would query:

$schedule | ?{ $_.Venue -eq "6C" }

I’ve combined this with the following script:

function Get-ScNextEvent {
    param(
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        $Schedule,
        [parameter(Mandatory = $false)]
        [uint] $Hour = 1
    )
    $result = $Schedule | Where-Object { ($_.StartTime -ge [DateTime]::Now) -and ($_.EndTime -le [DateTime]::Now.AddHours($Hour))}

    return ($result | Sort-Object StartTime)
}

function Get-ScCurrentEvent {
    param(
        [parameter(Mandatory = $true, ValueFromPipeline = $true)]
        $Schedule
    )
    $result = $Schedule | Where-Object { ($_.StartTime -ge [DateTime]::Now) -and ($_.EndTime -le [DateTime]::Now)}

    return ($result | Sort-Object StartTime)
}

This will retrieve the data about the next and current event that taking place.

Other PowerShell Core Applications

Schedule is not only place I have utilized PowerShell Core. Another area I use PowerShell Core is in area of generating form letters. Since I have the letter source as LaTeX source, this is matter of passing the personalized arguments through parameters. Since PowerShell contains the functionality to convert a CSV into data structure, the list of the names are populated as CSV.

function process {
    param(
        [Parameter(position = 0, mandatory = $true)]
        $Name,
        [Parameter(position = 1, mandatory = $true)]
        $Identifier
        )
    $OutputEncoding = [System.Text.Encoding]::GetEncoding('shift_jis')
    $docGuid =  [guid]::NewGuid().ToString()

    uplatex -kanji=utf8 --no-guestt-input-enc -jobname="Welcome_$Identifier" "\newcommand\scguestname{$Name}\input{2019_welcome.tex}"
    dvipdfmx "Welcome_$Identifier"

    Remove-Item @("Welcome_${Identifier}.aux", "Welcome_${Identifier}.log", "Welcome_${Identifier}.out", "Welcome_${Identifier}.dvi") -ErrorAction SilentlyContinue
    $OutputEncoding = New-Object System.Text.ASCIIEncoding
}

$names = Import-Csv welcome.csv

foreach($item in $names)
{
    $currentloc = (Get-Location).Path
    $identifier = $item.Name -replace " ","_"
    Write-Host "$identifier"
    $fileExist = Test-Path (Join-Path -Path $currentloc -ChildPath "Welcome_${identifier}.pdf")
    Pop-Location
    if($fileExist -eq $False)
    {
        process -Identifier $identifier -Name $item.JapaneseName
    }
    else {
        Write-Host -BackgroundColor Red "File exists, please delete a PDF file if you really need update this file."
    }

Because of the way the command line arguments passed, this is the area where I had struggle running this under Windows (because of the way the frontend handles character encoding) and had to use Windows Subsystem for Linux (WSL) to generate Japanese letters; but since PowerShell Core is available both for Linux and Windows, same components and scripts are used unmodified.

This will take about 30 seconds to generate 20 letters.

Conclusion

PowerShell Core provided, cross-platform and consistent environment to support data wrangling within limited area of relations tasks I was handling.

I am planning to improve the system to support schedule conflict, workload verification as well as staffing.