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+--[[
+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.
+
+]]--
+
+local util = require "luci.util"
+local config = require "luci.config"
+local tparser = require "luci.template.parser"
+
+local tostring, pairs, loadstring = tostring, pairs, loadstring
+local setmetatable, loadfile = setmetatable, loadfile
+local getfenv, setfenv, rawget = getfenv, setfenv, rawget
+local assert, type, error = assert, type, error
+
+--- LuCI template library.
+module "luci.template"
+
+config.template = config.template or {}
+viewdir = config.template.viewdir or util.libpath() .. "/view"
+
+
+-- Define the namespace for template modules
+context = util.threadlocal()
+
+--- Render a certain template.
+-- @param name Template name
+-- @param scope Scope to assign to template (optional)
+function render(name, scope)
+ return Template(name):render(scope or getfenv(2))
+end
+
+--- Render a template from a string.
+-- @param template Template string
+-- @param scope Scope to assign to template (optional)
+function render_string(template, scope)
+ return Template(nil, template):render(scope or getfenv(2))
+end
+
+
+-- Template class
+Template = util.class()
+
+-- Shared template cache to store templates in to avoid unnecessary reloading
+Template.cache = setmetatable({}, {__mode = "v"})
+
+
+-- Constructor - Reads and compiles the template on-demand
+function Template.__init__(self, name, template)
+ if name then
+ self.template = self.cache[name]
+ self.name = name
+ else
+ self.name = "[string]"
+ end
+
+ -- Create a new namespace for this template
+ self.viewns = context.viewns
+
+ -- If we have a cached template, skip compiling and loading
+ if not self.template then
+
+ -- Compile template
+ local err
+ local sourcefile
+
+ if name then
+ sourcefile = viewdir .. "/" .. name .. ".htm"
+ self.template, _, err = tparser.parse(sourcefile)
+ else
+ sourcefile = "[string]"
+ self.template, _, err = tparser.parse_string(template)
+ end
+
+ -- If we have no valid template throw error, otherwise cache the template
+ if not self.template then
+ error("Failed to load template '" .. name .. "'.\n" ..
+ "Error while parsing template '" .. sourcefile .. "':\n" ..
+ (err or "Unknown syntax error"))
+ elseif name then
+ self.cache[name] = self.template
+ end
+ end
+end
+
+
+-- Renders a template
+function Template.render(self, scope)
+ scope = scope or getfenv(2)
+
+ -- Put our predefined objects in the scope of the template
+ setfenv(self.template, setmetatable({}, {__index =
+ function(tbl, key)
+ return rawget(tbl, key) or self.viewns[key] or scope[key]
+ end}))
+
+ -- Now finally render the thing
+ local stat, err = util.copcall(self.template)
+ if not stat then
+ error("Failed to execute template '" .. self.name .. "'.\n" ..
+ "A runtime error occured: " .. tostring(err or "(nil)"))
+ end
+end