Module:Book

Documentation for this module may be created at Module:Book/doc

-- Module:Book
-- Purpose: Provides utility functions for organizing books, sections, and chapters semantically with navigation and author formatting.
local p = {}



-- Function to split a string by semicolon
local function split(str, sep)
  local t = {}
  for s in string.gmatch(str, "([^" .. sep .. "]+)") do
    table.insert(t, s)
  end
  return t
end





local function queryParent(pageName)
  -- Ensure argument exists
  if not pageName then return nil end
  -- Run semantic query
  local queryResult = mw.smw.ask {
    '[[' .. pageName .. ']]',
    '?Has parent page#-',
    'mainlabel=-'
  }
  -- Return result
  if queryResult and #queryResult > 0 then
    return queryResult[1]['Has parent page']
  end
  -- or nothing
  return nil
end






-- Retrieves the book title from the wiki message or defaults to "Book Index".
function p.getBook()
  -- Try to get the book title from wiki-book-title message
  local book = mw.message.new('wiki-book-title')
  -- Set default fallback value
  local renderBook = 'Book Index'
  -- Check if the message exists and has content
  if book:exists() and not book:isBlank() then
    -- Preprocess the message content to handle any wiki markup
    renderBook = book:plain()
  end
  return renderBook
end

function p.getContext(frame)
  -- Get full page name
  local hasTitle = mw.title.getCurrentTitle().fullText
  -- Get template parameters
  local args = frame:getParent().args
  -- Get book index
  local isPartOf = p.getBook()
  -- Cache values
  local hasParent = args['Has parent page'] or queryParent(hasTitle) or isPartOf or ''
  local hasType = args['Has book element name'] or 'Page'
  local hasOrder = tonumber(args['Has order']) or 0
  local hasLeadAuthorsString = args['Has lead authors'] or ''
  local hasContributingAuthorsString = args['Has contributing authors'] or ''
  -- Build context
  local context = {
    hasTitle = hasTitle,
    hasParent = hasParent,
    hasType = hasType,
    hasOrder = hasOrder,
    leadAuthors = hasLeadAuthorsString,
    leadAuthorsArray = hasLeadAuthorsString ~= '' and split(hasLeadAuthorsString, ';') or {},
    contributingAuthors = hasContributingAuthorsString,
    contributingAuthorsArray = hasContributingAuthorsString ~= '' and split(hasContributingAuthorsString, ';') or
    {},
    book = p.getBook()
  }
  return context
end

local function setProperties(context)
  -- Ensure argument exists
  if not context then return end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Join authors
    local leadAuthorsArray = context.leadAuthorsArray
    local contributingAuthorsArray = context.contributingAuthorsArray
    -- Merge into a single table
    local allAuthors = {}
    for _, a in ipairs(leadAuthorsArray) do table.insert(allAuthors, a) end
    for _, a in ipairs(contributingAuthorsArray) do table.insert(allAuthors, a) end
    -- Combine back into a semicolon-separated string
    local authorsString = table.concat(allAuthors, ';')
    -- Get property values from the context
    local properties = {
      'Has parent page=' .. context.hasParent,
      'Has book element name=' .. context.hasType,
      'Has order=' .. context.hasOrder,
      'Has lead author=' .. context.leadAuthors,
      '+sep=;',
      'Has contributing author=' .. context.contributingAuthors,
      '+sep=;',
      'Has author=' .. authorsString,
      '+sep=;',
    }
    -- Set properties
    mw.smw.set(properties)
  end
  return
end




-- Formats a list of authors into either a string or HTML list format.
-- Input:
--   authors: string or table containing author names
--   outputFormat: 'str' for comma-separated, 'ul' for HTML unordered list
local function formatAuthors(authors, outputFormat)
  if not authors or authors == '' then
    return ''
  end

  local authorList = {}

  -- Handle different input types
  if type(authors) == 'table' then
    -- Table input - assume it's already a list of authors
    for _, author in ipairs(authors) do
      if author and author ~= '' then
        table.insert(authorList, tostring(author))
      end
    end
  elseif type(authors) == 'string' then
    -- Check if it's HTML content (contains <ul> or <li>)
    if authors:match('<%s*ul%s*>') or authors:match('<%s*li%s*>') then
      -- Already HTML, convert to plain text format for string output
      if outputFormat ~= 'ul' then
        -- Extract authors from HTML
        local result = {}
        for author in authors:gmatch('<li[^>]*>(.-)</li>') do
          -- Remove any remaining HTML tags and trim whitespace
          local cleanAuthor = author:match("^%s*(.-)%s*$")
          if cleanAuthor ~= "" then
            table.insert(result, cleanAuthor)
          end
        end
        if #result == 0 then
          return ''
        end
        -- Format as string regardless of how many authors
        if #result == 1 then
          return result[1]
        elseif #result == 2 then
          return result[1] .. ', and ' .. result[2]
        else
          local finalResult = ''
          for i, author in ipairs(result) do
            if i == #result then
              finalResult = finalResult .. ', and ' .. author
            else
              finalResult = finalResult .. author .. ', '
            end
          end
          return finalResult
        end
      else
        -- Return HTML as-is for ul format
        return authors
      end
    else
      -- String with semicolon delimiter
      for author in authors:gmatch("[^;]+") do
        local trimmed = author:match("^%s*(.-)%s*$")
        if trimmed ~= "" then
          table.insert(authorList, trimmed)
        end
      end
    end
  end

  -- If we got here and authorList is empty, return empty string
  if #authorList == 0 then
    return ''
  end

  -- Format based on output format
  if outputFormat == 'ul' then
    local html = mw.html.create('ul'):css({
      ['margin'] = '0'
    })
    for _, author in ipairs(authorList) do
      html:tag('li'):wikitext(author)
    end
    return tostring(html)
  else
    -- String format - join with commas and "and"
    if #authorList == 1 then
      return authorList[1]
    elseif #authorList == 2 then
      return authorList[1] .. ' and ' .. authorList[2]
    else
      local result = ''
      for i, author in ipairs(authorList) do
        if i == #authorList then
          result = result .. ' and ' .. author
        else
          result = result .. author .. ', '
        end
      end
      return result
    end
  end
end




-- Get children of current page
local function getChildren(context)
  -- Ensure argument exists
  if not context then return {} end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Get current page
    local pageName = context.hasTitle or ''
    -- Ensure context is aware of the parent page
    if pageName and pageName ~= '' then
      -- Get children
      local queryResult = mw.smw.ask {
        '[[:+]][[Has parent page::' .. pageName .. ']]',
        '?#-=Page',
        '?Has book element name',
        '?Has order',
        '?Has lead author',
        '?Has contributing author',
        'mainlabel=-',
        'sort=Has order',
        'order=asc'
      }
      return queryResult or {}
    end
  else
    return {}
  end
end




-- Render children of current page
local function renderChildren(context)
  -- Ensure argument exists
  if not context then return '' end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Get children
    local children = getChildren(context)
    -- Ensure children exist
    if #children == 0 then return '' end
    -- Set default fallback list heading
    local renderIntro = 'Contents'
    -- Try custom list heading
    local intro = mw.message.new('wiki-book-children-list-intro', context.hasType)
    if intro:exists() and not intro:isBlank() then
      local frame = mw.getCurrentFrame()
      renderIntro = frame:preprocess(intro:plain())
    end
    -- Assemble
    local html = mw.html.create()
    -- Create contents block
    html:tag('div'):css({
      ['font-weight'] = 'bold',
      ['font-size'] = '1.2em'
    }):wikitext(renderIntro)
    -- Create list
    local ul = html:tag('ul'):addClass('wiki-book-page-subordinates')
    -- Iterate through children to build list items
    for _, child in ipairs(children) do
      li = ul:tag('li'):wikitext(
        string.format('[[%s]]', child['Page'])
      )
      -- Append lead authors if exist
      local leadAuthors = child['Has lead author'] or nil
      if leadAuthors then
        local leadAuthorsText = formatAuthors(leadAuthors, 'str')
        li:tag('span'):wikitext(string.format(' (%s)', leadAuthorsText))
      end
      -- Append contributing authors if exist
      local contributingAuthors = child['Has contributing author'] or nil
      if contributingAuthors then
        local contributingAuthorsText = formatAuthors(contributingAuthors, 'str')
        li:tag('span'):wikitext(string.format(' (%s)', contributingAuthorsText))
      end
    end
    return html
  else
    return ''
  end
end




-- Generate breadcrumb trail
local function getBreadcrumbs(context)
  -- Set table to store bredcrumbs
  local breadcrumbs = {}
  -- Ensure argument exists
  if not context then return end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Retrieve current title from the context
    local current = context.hasTitle or nil
    -- Iterate through parent pages
    while current do
      local parent = queryParent(current)
      if parent and parent ~= '' then
        table.insert(breadcrumbs, 1, {
          crumb = string.format('[[%s]]', current)
        })
        -- Get the actual parent page title
        local parentTitle = mw.title.new(parent)
        if parentTitle and parentTitle.exists then
          current = parentTitle.fullText
        else
          break
        end
      else
        table.insert(breadcrumbs, 1, {
          crumb = string.format('[[%s]]', current)
        })
        break
      end
    end
  end
  -- Return a table with breadcrumbs
  return breadcrumbs
end




-- Decide on the breadcrumbs separator
local function getBreadcrumbsSeparator()
  local msg = mw.message.new('wiki-book-breadcrumb-separator')
  if msg:exists() and not msg:isBlank() then
    return msg:plain()
  else
    return '>'
  end
end


local function renderCreateButton()
  local html = mw.html.create()
  -- Provide class to optionally hide the button via group CSS.
  local button = html:tag('li')
      :addClass('show-sysop')
      :attr('id', 'create-subpage-trigger')
      :attr('type', 'button')
      :attr('taborder', '0')
      :attr('title', 'Add a subpage.')
      :tag('span')
      :addClass('icon')
      :wikitext('➕')
  return tostring(html)
end


-- Generate breadcrumb HTML
local function renderBreadcrumbs(context)
  -- Set table to store bredcrumbs
  local breadcrumbs = {}
  -- Ensure argument exists
  if not context then return end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Fill breadcrumbs from contents
    breadcrumbs = getBreadcrumbs(context)
    if not breadcrumbs or #breadcrumbs == 0 then
      return {}
    end
    -- Get separator
    local separator = getBreadcrumbsSeparator()
    -- Assemble
    local html = mw.html.create()
    -- Create breadcrumbs bar
    local ul = html:tag('ul'):addClass('breadcrumbs')
    local i = 1
    -- Iterate through the table to build list items
    for _, breadcrumb in ipairs(breadcrumbs) do
      local li = ul:tag('li'):addClass('breadcrumb-item')
      local crumb = breadcrumb['crumb']
      -- Add special class to the last item
      if i == #breadcrumbs then
        li:addClass('breadcrumb-current')
      end
      li:wikitext(crumb):done()
      -- Add separator for non-last items
      if i < #breadcrumbs then
        ul:tag('li'):addClass('breadcrumb-separator'):wikitext(separator)
      end
      -- Push counter
      i = i + 1
    end
    ul:wikitext(renderCreateButton())
    return html
  end
end


-- Normalize node returned by either p.getContext() or mw.smw.ask() row
local function normalizeNode(node, parentTitle)
  -- node may be a context (hasTitle) or an SMW row (Page)
  local title = nil
  if type(node) == 'table' then
    title = node.hasTitle or node.Page or node['Page'] or ''
  end
  -- Build normalized context-like object
  local normalized = {
    hasTitle = title,
    hasParent = parentTitle or (node.hasParent and node.hasParent ~= '' and node.hasParent) or ''
  }
  -- preserve original fields if present (useful for rendering authors/order/etc.)
  if type(node) == 'table' then
    for k, v in pairs(node) do
      if normalized[k] == nil then normalized[k] = v end
    end
  end
  return normalized
end


-- Correct preorder flatten that normalizes nodes and sets hasParent for children
local function flattenBook(context)
  if not context or type(context) ~= 'table' then return {} end

  -- Ensure we work on a normalized node with hasTitle field
  local rootNode = normalizeNode(context)

  local ordered = {}
  -- local function to recurse using normalized nodes
  local function recurse(node)
    table.insert(ordered, node)

    -- getChildren expects a context-like table, so pass node with hasTitle
    local childrenRaw = getChildren({ hasTitle = node.hasTitle })
    if childrenRaw and #childrenRaw > 0 then
      for _, childRaw in ipairs(childrenRaw) do
        -- normalize child and set its hasParent to current node's title
        local childNode = normalizeNode(childRaw, node.hasTitle)
        recurse(childNode)
      end
    end
  end

  recurse(rootNode)
  return ordered
end

-- Render navigation using the corrected flattenBook
local function renderBookNavigation(context)
  if not context or type(context) ~= 'table' then return end

  -- Determine root: if you have a reliable p.getBook() (book root title), prefer that.
  -- Otherwise, fall back to using the provided context as root (flatten will handle descendants).
  local rootContext = nil
  if type(p) == 'table' and type(p.getBook) == 'function' then
    local bookTitle = p.getBook()
    if bookTitle and bookTitle ~= '' then
      rootContext = { hasTitle = bookTitle }
    end
  end
  if not rootContext then
    -- fallback: try to climb to top by repeatedly using getParent info from p.getContext in real usage,
    -- but here we'll use the current context as root to guarantee traversal of its subtree.
    rootContext = { hasTitle = context.hasTitle, hasParent = context.hasParent }
  end

  -- Flatten from the chosen root
  local bookPages = flattenBook(rootContext)
  if not bookPages or #bookPages == 0 then return end

  -- Find current index by matching hasTitle
  local currentIdx = nil
  for i, page in ipairs(bookPages) do
    if page.hasTitle == context.hasTitle or page.Page == context.hasTitle or page['Page'] == context.hasTitle then
      currentIdx = i
      break
    end
  end
  if not currentIdx then
    -- If the current page is not in the flattened list (e.g. rootContext was different),
    -- attempt to flatten from the real current context to find it
    local fallbackList = flattenBook(context)
    for i, page in ipairs(fallbackList) do
      if page.hasTitle == context.hasTitle then
        -- prepend fallbackList before bookPages to preserve order (but usually not needed)
        bookPages = fallbackList
        currentIdx = i
        break
      end
    end
  end
  if not currentIdx then return end

  local prevPage = bookPages[currentIdx - 1]
  local nextPage = bookPages[currentIdx + 1]

  -- Build HTML navigation
  local html = mw.html.create()
  local nav = html:tag('div'):addClass('horizontal-navigation')

  -- Previous
  local prevButton = nav:tag('div'):addClass('wiki-book-nav-prev')
  if prevPage and prevPage.hasTitle and prevPage.hasTitle ~= '' then
    prevButton:wikitext(string.format('< [[%s|%s]]', prevPage.hasTitle, 'Previous Article'))
  else
    prevButton:wikitext('< Previous Article')
  end

  nav:tag('span'):wikitext('|')

  local parentTitle = context.hasParent or ''
  if parentTitle ~= '' then
    nav:tag('div'):addClass('wiki-book-nav-info')
        :wikitext(string.format('[[%s|%s]]', parentTitle, 'Parent Article'))
  else
    nav:tag('div'):addClass('wiki-book-nav-info')
        :wikitext('Root Article')
  end

  nav:tag('span'):wikitext('|')

  local nextButton = nav:tag('div'):addClass('wiki-book-nav-next')
  if nextPage and nextPage.hasTitle and nextPage.hasTitle ~= '' then
    nextButton:wikitext(string.format('[[%s|%s]] >', nextPage.hasTitle, 'Next Article'))
  else
    nextButton:wikitext('Next Article >')
  end

  return html
end





local function renderAuthors(context)
  -- Ensure argument exists
  if not context then return '' end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Get lead authors if exist
    local leadAuthors = context.leadAuthors or nil
    local contributingAuthors = context.contributingAuthors or nil
    -- Ensure that at least one author exist
    if not leadAuthors and not contributingAuthors then return '' end
    -- Assemble
    local html = mw.html.create()
    -- Create authors bar
    local authorBar = html:tag('div'):addClass('wiki-book-authors')
    -- Render lead authors list
    if leadAuthors and leadAuthors ~= '' then
      local ul = authorBar:tag('ul'):addClass('wiki-book-authors-list')
      local label = 'Lead Author:'
      if #context.leadAuthorsArray > 1 then
        label = 'Lead Authors:'
      end
      ul:tag('li'):addClass('wiki-book-authors-list-header'):wikitext(label)
      ul:tag('li'):wikitext(formatAuthors(leadAuthors, 'str'))
    end
    -- Render contributing authors list
    if contributingAuthors and contributingAuthors ~= '' then
      local ul = authorBar:tag('ul'):addClass('wiki-book-authors-list')
      local label = 'Contributing Author:'
      if #context.contributingAuthorsArray > 1 then
        label = 'Contributing Authors:'
      end
      ul:tag('li'):addClass('wiki-book-authors-list-header'):wikitext(label)
      ul:tag('li'):wikitext(formatAuthors(contributingAuthors, 'str'))
    end
    return html
  else
    return ''
  end
end



-- Form input
local function renderForm(context)
  -- Ensure argument exists
  if not context then return end
  -- Ensure argument has correct type
  if context and type(context) == 'table' then
    -- Query for the highest existing child number in this parent
    local lastNumberResult = mw.smw.ask {
      '[[Has parent page::' .. context.hasTitle .. ']]',
      '?Has order#-',
      'sort=Has order',
      'order=desc',
      'limit=1'
    } or {}
    -- Calculate next chapter number
    local nextNumber = 1
    if type(lastNumberResult) == 'table' and #lastNumberResult > 0 then
      local lastOrder = lastNumberResult[1] and lastNumberResult[1]['Has order']
      if lastOrder then
        local num = tonumber(lastOrder)
        if num then
          nextNumber = num + 1
        end
      end
    end
    -- Get current frame
    local frame = mw.getCurrentFrame()
    -- Create form input with pre-filled data
    local form = frame:callParserFunction(
      '#forminput',
      'form=Subpage',
      'query string=Subpage[Has parent page]=' .. context.hasTitle .. '&Subpage[Has order]=' .. nextNumber
    )
    -- Get prompt message
    local prompt = mw.message.new('wiki-book-create-subpage-prompt')
    local renderPrompt = ''
    if prompt:exists() and not prompt:isBlank() then
      renderPrompt = frame:preprocess(prompt:plain())
    end
    -- Build HTML interface
    local html = mw.html.create()
    -- Provide class to optionally hide the form in group CSS. Triggered by
    local formwrapper = html:tag('div'):attr('id', 'create-subpage-wrapper'):addClass('sysop-show')
        :css({
          ['padding'] = '.5rem 1rem',
          ['background-color'] = '#f7f7f7',
          ['margin'] = '1rem 0',
          ['display'] = 'none'
        })
    -- Set form heading
    formwrapper:tag('div'):css({
      ['font-weight'] = 'bold',
      ['font-size'] = '1.2em'
    }):wikitext('Create a new page in this ' .. context.hasType):done()
    -- Render prompt if exists
    if renderPrompt ~= '' then
      formwrapper:tag('div'):wikitext(renderPrompt)
    end
    -- Render form
    formwrapper:wikitext(form)
    return tostring(html)
  else
    return ''
  end
end




local function loadWidget(frame)
  local widget = frame:callParserFunction(
    '#widget', 'wiki-book'
  )
  return widget
end


-- Normalize node for hierarchy with metadata
local function normalizeHierarchyNode(node, parentTitle)
  local title = node.hasTitle or node.Page or node['Page'] or ''
  local hasParent = parentTitle or (node.hasParent and node.hasParent ~= '' and node.hasParent) or ''
  local hasType = node.hasType or node['Has book element name'] or 'Page'
  local hasOrder = tonumber(node.hasOrder) or tonumber(node['Has order']) or 0
  local leadAuthors = node.leadAuthors or node['Has lead author'] or ''
  local contributingAuthors = node.contributingAuthors or node['Has contributing author'] or ''

  return {
    hasTitle = title,
    hasParent = hasParent,
    hasType = hasType,
    hasOrder = hasOrder,
    leadAuthors = leadAuthors,
    contributingAuthors = contributingAuthors,
    children = {}
  }
end

-- Recursively build full book hierarchy
local function buildBookHierarchy(rootContext)
  if not rootContext or type(rootContext) ~= 'table' then return {} end

  local rootNode = normalizeHierarchyNode(rootContext)

  local function recurse(node)
    local childrenRaw = getChildren({ hasTitle = node.hasTitle })
    node.children = {}
    if childrenRaw and #childrenRaw > 0 then
      for _, childRaw in ipairs(childrenRaw) do
        local childNode = normalizeHierarchyNode(childRaw, node.hasTitle)
        recurse(childNode)
        table.insert(node.children, childNode)
      end
    end
  end

  recurse(rootNode)
  return rootNode
end

-- Helper to normalize type string for CSS class
local function normalizeClassName(str)
  str = tostring(str or '')
  str = str:lower()
  str = str:gsub('%s+', '-')   -- spaces → hyphens
  str = str:gsub('[^%w%-]', '') -- remove invalid characters
  return str
end

-- Render book hierarchy as HTML <ul><li> with classes and data-level
local function renderBookHierarchyHTML(node, level)
  if not node or not node.hasTitle then return '' end
  level = level or 0

  local html = mw.html.create()
  local ul = html:tag('ul'):addClass('wiki-book-tree')

  local function recurseRender(n, parentHtml, depth)
    local li = parentHtml:tag('li')

    -- Add class: wiki-book-{normalized-type}
    local className = 'wiki-book-' .. normalizeClassName(n.hasType or 'page')
    li:addClass(className)

    -- Add data-level attribute
    li:attr('data-level', tostring(depth))

    -- Determine prefix for first-level elements
    local prefix = ''
    if depth == 1 then
      prefix = string.format('<span class="wiki-book-tree-prefix">Part %d:</span> ', n.hasOrder or 1)
    end

    -- Display title + optional metadata (only first-level)
    local text = ''
    if depth == 1 then
      text = string.format(
        '%s[[%s]]',
        prefix,
        n.hasTitle
      )
    else
      text = string.format('[[%s]]', n.hasTitle)
    end
    li:wikitext(text)
    -- Optionally show authors at any level
    if (n.leadAuthors and n.leadAuthors ~= '') or (n.contributingAuthors and n.contributingAuthors ~= '') then
      local authorText = ''
      if n.leadAuthors and n.leadAuthors ~= '' then
        authorText = authorText .. 'Lead: ' .. formatAuthors(n.leadAuthors, 'str')
      end
      if n.contributingAuthors and n.contributingAuthors ~= '' then
        if authorText ~= '' then authorText = authorText .. ' | ' end
        authorText = authorText .. 'Contrib: ' .. formatAuthors(n.contributingAuthors, 'str')
      end
      li:tag('div'):addClass('wiki-book-tree-authors'):wikitext(authorText)
    end
    -- Render children recursively
    if n.children and #n.children > 0 then
      local ul = li:tag('ul')
      for _, child in ipairs(n.children) do
        recurseRender(child, ul, depth + 1)
      end
    end
  end

  -- Suppress root element; render only its children
  if node.children and #node.children > 0 then
    for _, child in ipairs(node.children) do
      recurseRender(child, ul, 1)
    end
  end

  return tostring(html)
end


-- Module function to display book hierarchy
function p.showBookHierarchy(frame)
  local context = p.getContext(frame)
  local rootTitle = p.getBook() or context.hasTitle
  local rootContext = { hasTitle = rootTitle }
  local tree = buildBookHierarchy(rootContext)
  local widget = loadWidget(frame)
  return renderBookHierarchyHTML(tree) .. tostring(widget)
end

local function renderBookFooter(frame)
  local footer = mw.message.new('wiki-book-footer')
  local renderFooter = frame:preprocess(footer:plain())
  local html = mw.html.create()
  html:tag('div'):attr('id', 'wiki-book-footer')
      :tag('div'):addClass('wiki-book-footer-content'):wikitext(renderFooter)
  return html
end


function p.subpage(frame)
  local context = p.getContext(frame)
  setProperties(context)
  local breadcrumbs = renderBreadcrumbs(context)
  local navigation  = renderBookNavigation(context)
  local children    = renderChildren(context)
  local createform  = renderForm(context)
  local authors     = renderAuthors(context)
  local footer      = renderBookFooter(frame)
  local widget      = loadWidget(frame)


  local defaultform = frame:callParserFunction(
    '#default_form', 'Subpage'
  )

  return tostring(breadcrumbs)
      .. tostring(navigation)
      .. tostring(children)
      .. tostring(createform)
      .. tostring(authors)
      .. tostring(footer)
      .. tostring(widget)
end

return p