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Diffstat (limited to 'libs/web/luasrc/template.lua')
-rw-r--r-- | libs/web/luasrc/template.lua | 220 |
1 files changed, 220 insertions, 0 deletions
diff --git a/libs/web/luasrc/template.lua b/libs/web/luasrc/template.lua new file mode 100644 index 000000000..369aa0a30 --- /dev/null +++ b/libs/web/luasrc/template.lua @@ -0,0 +1,220 @@ +--[[ +LuCI - 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("luci.template", package.seeall) + +require("luci.config") +require("luci.util") +require("luci.fs") +require("luci.http") + +viewdir = luci.sys.libpath() .. "/view/" + + +-- Compile modes: +-- none: Never compile, only use precompiled data from files +-- memory: Always compile, do not save compiled files, ignore precompiled +-- file: Compile on demand, save compiled files, update precompiled +compiler_mode = "memory" + + +-- 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 = { + write = io.write, + include = function(name) Template(name):render(getfenv(2)) 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 = {} + luci.util.extfenv(expr_add, "expr", expr) + + -- Save all expressiosn to table "expr" + template = template:gsub("<%%(.-)%%>", expr_add) + + local function sanitize(s) + s = luci.util.escape(s) + s = luci.util.escape(s, "'") + s = luci.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_pexec = "'..(%s or '')..'" + 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 = r_pexec:format(v:sub(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 + +-- Oldstyle render shortcut +function render(name, scope, ...) + scope = scope or getfenv(2) + local s, t = pcall(Template, name) + if not s then + error(t) + else + t:render(scope, ...) + end +end + + +-- Template class +Template = luci.util.class() + +-- Shared template cache to store templates in to avoid unnecessary reloading +Template.cache = {} + + +-- Constructor - Reads and compiles the template on-demand +function Template.__init__(self, name) + if self.cache[name] then + self.template = self.cache[name] + else + self.template = nil + end + + -- Create a new namespace for this template + self.viewns = {} + + -- Copy over from general namespace + for k, v in pairs(viewns) do + self.viewns[k] = v + end + + -- If we have a cached template, skip compiling and loading + if self.template then + return + end + + -- Compile and build + local sourcefile = viewdir .. name .. ".htm" + local compiledfile = viewdir .. name .. ".lua" + local err + + if compiler_mode == "file" then + local tplmt = luci.fs.mtime(sourcefile) + local commt = luci.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 + local source + source, err = luci.fs.readfile(sourcefile) + + if source then + local compiled = compile(source) + luci.fs.writefile(compiledfile, compiled) + self.template, err = loadstring(compiled) + end + else + self.template, err = loadfile(compiledfile) + end + + elseif compiler_mode == "none" then + self.template, err = loadfile(self.compiledfile) + + elseif compiler_mode == "memory" then + local source + source, err = luci.fs.readfile(sourcefile) + if source then + self.template, err = loadstring(compile(source)) + end + + end + + -- If we have no valid template throw error, otherwise cache the template + if not self.template then + error(err) + else + self.cache[name] = self.template + end +end + + +-- Renders a template +function Template.render(self, scope) + scope = scope or getfenv(2) + + -- Save old environment + local oldfenv = getfenv(self.template) + + -- Put our predefined objects in the scope of the template + luci.util.resfenv(self.template) + luci.util.updfenv(self.template, scope) + luci.util.updfenv(self.template, self.viewns) + + -- Now finally render the thing + self.template() + + -- Reset environment + setfenv(self.template, oldfenv) +end |