Module:TemplateStructure

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

-- Module:TemplateStructure
-- A module for rendering templates using a modular, block-based approach with error handling.

local p = {}

-- Local trim function: removes leading and trailing whitespace.
local function trim(s)
    return (s:gsub("^%s+", ""):gsub("%s+$", ""))
end

-- Format an error as an HTML comment for debugging
local function formatErrorComment(blockIndex, errorMsg)
    return string.format(
        "<!-- WARNING COMMENT: Block #%d failed with error: %s -->",
        blockIndex,
        tostring(errorMsg)
    )
end

--[[
    p.render(args, config)
    
    Renders a table using a modular, block-based approach.
    
    Parameters:
      args   - Template parameters (passed to each block function)
      config - Configuration options:
          tableClass: CSS class for the table (default: "template-table")
          tableAttrs: Additional table attributes (default: 'cellpadding="2"')
          blocks:     Functions that generate table rows
                      Each accepts (args, config) and returns a string
          continueOnError: Continue rendering if a block fails (default: true)
    
    Returns:
      Wikitext markup for the complete table
]]
function p.render(args, config)
    config = config or {}
    local tableClass = config.tableClass or "template-table"
    local tableAttrs = config.tableAttrs or 'cellpadding="2"'
    local blocks = config.blocks or {}
    local continueOnError = config.continueOnError
    if continueOnError == nil then continueOnError = true end -- Default to true

    -- Begin the table markup.
    local result = {}
    table.insert(result, string.format('{| class="%s" %s', tableClass, tableAttrs))
    
    -- Track errors for debugging
    local errors = {}
    
    -- Process each block function in the supplied order.
    for i, block in ipairs(blocks) do
        if type(block) == "function" then
            -- Protect block execution to avoid template failure
            local success, blockOutput = pcall(function() 
                return block(args, config) 
            end)
            
            if success then
                blockOutput = trim(blockOutput)
                if blockOutput ~= "" then
                    table.insert(result, blockOutput)
                end
            else
                -- Record error
                table.insert(errors, {
                    blockIndex = i,
                    error = blockOutput -- In pcall, error message is returned as second value
                })
                
                -- Add error comment
                table.insert(result, "<!-- WARNING COMMENT: Block #" .. i .. " failed with error: " .. tostring(blockOutput) .. " -->")
                
                -- If we shouldn't continue on error, break the loop
                if not continueOnError then
                    break
                end
            end
        else
            -- Add warning for non-function blocks
            table.insert(result, "<!-- WARNING COMMENT: Block #" .. i .. " is not a function and will be skipped. -->")
        end
    end
    
    -- Close the table
    table.insert(result, "|}")
    
    -- Add error debug comments if any errors occurred
    if #errors > 0 then
        local errorOutput = {"<!-- TEMPLATE_STRUCTURE_DEBUG: errors=" .. #errors}
        for i, err in ipairs(errors) do
            table.insert(errorOutput, " E" .. i .. "=Block" .. err.blockIndex .. ":" .. tostring(err.error))
        end
        table.insert(errorOutput, " -->")
        table.insert(result, table.concat(errorOutput, ""))
    end
    
    local finalOutput = table.concat(result, "\n")
    return trim(finalOutput)
end

return p