* new project: ff-luci - Freifunk Lua Configuration Interface

1 files changed, 189 insertions, 0 deletions

diff --git a/src/ffluci/template.lua b/src/ffluci/template.lua
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+--[[
+FFLuCI - Template Parser
+
+Description:
+A template parser supporting includes, translations, Lua code blocks
+and more. It can be used either as a compiler or as an interpreter.
+
+FileId: $Id$
+
+License:
+Copyright 2008 Steven Barth <steven@midlink.org>
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at 
+
+	http://www.apache.org/licenses/LICENSE-2.0 
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+]]--
+module("ffluci.template", package.seeall)
+
+require("ffluci.config")
+require("ffluci.util")
+require("ffluci.fs")
+require("ffluci.i18n")
+require("ffluci.model.uci")
+
+viewdir = ffluci.fs.dirname(ffluci.util.__file__()) .. "view/"
+
+
+-- Compile modes:
+-- none:	Never compile, only render precompiled
+-- memory:	Always compile, do not save compiled files, ignore precompiled 
+-- always:  Same as "memory" but also saves compiled files
+-- smart:	Compile on demand, save compiled files, update precompiled
+compiler_mode = "smart"
+
+
+-- This applies to compiler modes "always" and "smart"
+--
+-- Produce compiled lua code rather than lua sourcecode
+-- WARNING: Increases template size heavily!!!
+-- This produces the same bytecode as luac but does not have a strip option
+compiler_enable_bytecode = false
+
+
+-- Define the namespace for template modules
+viewns = {
+	translate  = ffluci.i18n.translate,
+	config     = ffluci.model.uci.get,
+	controller = os.getenv("SCRIPT_NAME"),
+	media      = ffluci.config.mediaurlbase,
+	include    = function(name) return render(name, getfenv(2)) end, 
+	write      = io.write
+}
+
+
+-- Compiles and builds a given template
+function build(template, compiled)	
+	local template = compile(ffluci.fs.readfile(template))
+	
+	if compiled then
+		ffluci.fs.writefile(compiled, template)
+	end
+	
+	return template
+end
+
+
+-- Compiles a given template into an executable Lua module
+function compile(template)
+	-- Search all <% %> expressions (remember: Lua table indexes begin with #1)
+	local function expr_add(command)
+		table.insert(expr, command)
+		return "<%" .. tostring(#expr) .. "%>"
+	end
+	
+	-- As "expr" should be local, we have to assign it to the "expr_add" scope 
+	local expr = {}
+	ffluci.util.extfenv(expr_add, "expr", expr)
+	
+	-- Save all expressiosn to table "expr"
+	template = template:gsub("<%%(.-)%%>", expr_add)
+	
+	local function sanitize(s)
+		s = ffluci.util.escape(s)
+		s = ffluci.util.escape(s, "'")
+		s = ffluci.util.escape(s, "\n")
+		return s
+	end
+	
+	-- Escape and sanitize all the template (all non-expressions)
+	template = sanitize(template)
+
+	-- Template module header/footer declaration
+	local header = "write('"
+	local footer = "')"
+	
+	template = header .. template .. footer
+	
+	-- Replacements
+	local r_include = "')\ninclude('%s')\nwrite('"
+	local r_i18n    = "'..translate('%1','%2')..'"
+	local r_uci     = "'..config('%1','%2','%3')..'"
+	local r_pexec   = "'..%s..'"
+	local r_exec    = "')\n%s\nwrite('"
+	
+	-- Parse the expressions
+	for k,v in pairs(expr) do
+		local p = v:sub(1, 1)
+		local re = nil
+		if p == "+" then
+			re = r_include:format(sanitize(string.sub(v, 2)))
+		elseif p == ":" then
+			re = sanitize(v):gsub(":(.-) (.+)", r_i18n)
+		elseif p == "~" then
+			re = sanitize(v):gsub("~(.-)%.(.-)%.(.+)", r_uci)
+		elseif p == "=" then
+			re = r_pexec:format(string.sub(v, 2))
+		else
+			re = r_exec:format(v)
+		end
+		template = template:gsub("<%%"..tostring(k).."%%>", re)
+	end
+
+	if compiler_enable_bytecode then 
+		tf = loadstring(template)
+		template = string.dump(tf)
+	end
+	
+	return template
+end
+
+
+-- Returns and builds the template for "name" depending on the compiler mode
+function get(name)	
+	local templatefile = viewdir .. name .. ".htm"
+	local compiledfile = viewdir .. name .. ".lua"
+	local template = nil
+	
+	if compiler_mode == "smart" then
+		local tplmt = ffluci.fs.mtime(templatefile)
+		local commt = ffluci.fs.mtime(compiledfile)
+				
+		-- Build if there is no compiled file or if compiled file is outdated
+		if ((commt == nil) and not (tplmt == nil))
+		or (not (commt == nil) and not (tplmt == nil) and commt < tplmt) then
+			template = loadstring(build(templatefile, compiledfile))
+		else
+			template = loadfile(compiledfile)
+		end
+		
+	elseif compiler_mode == "none" then
+		template = loadfile(compiledfile)
+		
+	elseif compiler_mode == "memory" then
+		template = loadstring(build(templatefile))
+		
+	elseif compiler_mode == "always" then
+		template = loadstring(build(templatefile, compiledfile))
+				
+	else
+		error("Invalid compiler mode: " .. compiler_mode)
+		
+	end
+	
+	return template or error("Unable to load template: " .. name)
+end
+
+-- Renders a template
+function render(name, scope)
+	scope = scope or getfenv(2)
+	
+	-- Our template module
+	local view = get(name)
+	
+	-- Put our predefined objects in the scope of the template
+	ffluci.util.updfenv(view, scope)
+	ffluci.util.updfenv(view, viewns)
+	
+	-- Now finally render the thing
+	return view()
+end
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