Module:British regnal year

This module implements the {{British regnal year}} template. It converts a year in the Gregorian calendar into a British regnal year.

Syntax

{{#invoke:British regnal year|main|<year in Gregorian calendar>}}

Example

{{British regnal year|1952}} → Template:British regnal year

Data

The data for the module is stored in a table at Module:British regnal year/data. The module looks through the data list from newest to oldest, and returns the data for the first result where the input year is greater than or equal to the year value. The data table entries are organised as follows:

• year - the year that the template searches for when deciding what links to display. In most cases this is the year that the monarch's reign began, although it can be different if the history is complicated.
• linkCurrent - a wikilink to the current monarch's Wikipedia article.
• startYear - the regnal year of the year value for the current monarch. If this is the monarch's first year on the throne, this is 1; if it is their second year, this is 2, and so on.
• linkPrev - a wikilink to the Wikipedia article of the previous monarch.
• prevEndYear - the regnal year of the year value for the previous monarch.
• note - a short note about the years for this time period. This is displayed after the other content.

See also

• {{year in other calendars}}

---

-- This module implements {{British regnal year}}. It converts a year in the Gregorian
-- calendar to the equivalent English or British regnal year.

local data = mw.loadData( 'Module:British regnal year/data' )

local p = {}

function p.main( frame )
    -- If we are being called from #invoke, then the year is the first positional
    -- argument. If not, it is the frame parameter.
    local inputYear
    if frame == mw.getCurrentFrame() then
        inputYear = frame:getParent().args[ 1 ]
        local frameArgsYear = frame.args[ 1 ]
        if frameArgsYear then
            inputYear = frameArgsYear
        end
    else
        inputYear = frame
    end

    -- Convert the input to an integer if possible. Return "N/A" if the input could
    -- not be converted, or if the converted input is too big or too small.
    if type( inputYear ) ~= 'number' then
        inputYear = tonumber( inputYear )
    end
    if not inputYear then
        return "''N/A''"
    end
    local currentYear = tonumber( mw.language.getContentLanguage():formatDate( 'Y' ) )
    if inputYear < 1066 or inputYear > currentYear then
        return "''N/A''"
    end
    
    -- Find the year in the data page and display the output.
    for _, t in ipairs( data ) do
        local dataYear = t.year
        if inputYear >= dataYear then
            -- Get data values from the data page.
            local startYear = t.startYear
            local currentRegnalYear = inputYear - dataYear + startYear
            local linkCurrent = t.linkCurrent
            local prevEndYear = t.prevEndYear
            local linkPrev = t.linkPrev
            local note = t.note

            if inputYear > dataYear then
                -- Years with the same monarch.
                return mw.ustring.format(
                    '%d&nbsp;%s&nbsp;–&nbsp;%d&nbsp;%s%s',
                    currentRegnalYear - 1, linkCurrent, currentRegnalYear, linkCurrent, note or ''
                )
            elseif inputYear == dataYear and prevEndYear and linkPrev then
                -- Years with a different monarch.
                return mw.ustring.format(
                    '%d&nbsp;%s&nbsp;–&nbsp;%d&nbsp;%s%s',
                    prevEndYear, linkPrev, currentRegnalYear, linkCurrent, note or ''
                )
            else
                -- This should only match the year 1066.
                return mw.ustring.format(
                    '%d&nbsp;%s%s',
                    currentRegnalYear, linkCurrent, note or ''
                )
            end
        end
    end
end

return p