terom@8: """
terom@8:     Template handler
terom@8: """
terom@8: 
terom@50: from mako import exceptions, util
terom@50: from mako.runtime import Context
terom@8: from mako.template import Template
terom@32: import mako.lookup
terom@8: 
terom@46: from qmsk.web import http, helpers
terom@26: 
terom@8: # path to template files
terom@8: TEMPLATE_DIR = "templates"
terom@8: 
terom@8: # path to cached templates
terom@8: CACHE_DIR = "cache/templates"
terom@8: 
terom@8: # template file extension
terom@8: TEMPLATE_EXT = "tmpl"
terom@8: 
terom@70: class TemplateError (Exception) :
terom@8:     """
terom@8:         Raised by the template module functions
terom@8:     """
terom@8: 
terom@8:     pass
terom@8: 
terom@71: def fmt_mako_exception () :
terom@71:     """
terom@71:         Returns a string containing the Mako-ized error traceback (so that it includes the template data)
terom@71:     """
terom@71: 
terom@71:     return exceptions.text_error_template().render()
terom@71:  
terom@32: class TemplateLoader (mako.lookup.TemplateLookup) :
terom@8:     """
terom@32:         Our own specialization of mako's TemplateLookup
terom@8:     """
terom@8: 
terom@50:     def __init__ (self, path, fileext=TEMPLATE_EXT, _helper_class=helpers.Helpers, **env) :
terom@32:         """
terom@42:             Initialize to load templates located at path, with the given file extension.
terom@42: 
terom@50:             The given Helpers class is used to provide the helper methods
terom@50: 
terom@42:             The given **env list is supplied to every template render
terom@32:         """
terom@8: 
terom@32:         # store
terom@32:         self.path = path
terom@32:         self.fileext = fileext
terom@50:         self.helper_class = _helper_class
terom@42:         self.env = env
terom@42:             
terom@42:         # build the TemplateLookup
terom@42:         super(TemplateLoader, self).__init__(directories=[path], module_directory=CACHE_DIR)
terom@42:     
terom@50:     def _render (self, tpl, env, params) :
terom@42:         """
terom@42:             Render the given template with given env/params, returning the output as a unicode string, or raising a TemplateError
terom@42:         """
terom@42: 
terom@50:         # build our Helpers class
terom@50:         helpers = self.helper_class()
terom@50: 
terom@50:         # build the context from our env, and params
terom@42:         ctx = dict(
terom@42:             h       = helpers,
terom@42:         )
terom@42:         ctx.update(env)
terom@42:         ctx.update(params)
terom@42: 
terom@50:         # the buffer to use for unicode output
terom@50:         buf = util.FastEncodingBuffer(unicode=True)
terom@50: 
terom@50:         # the context to use
terom@50:         context = Context(buf, **ctx)
terom@50:         
terom@50:         # bind our helper
terom@50:         helpers._bind_ctx(context)
terom@50:         
terom@42:         try :
terom@50:             # render template
terom@50:             tpl.render_context(context)
terom@32:         
terom@42:         # a template may render other templates
terom@42:         except TemplateError :
terom@42:             raise
terom@42: 
terom@42:         except :
terom@50:             # raise a TemplateError with the details
terom@71:             raise TemplateError("tpl=%r, params=%r: %s" % (tpl, params, fmt_mako_exception()))
terom@50:         
terom@50:         else :
terom@50:             # return the unicode data
terom@50:             return buf.getvalue()
terom@8: 
terom@32:     def lookup (self, name) :
terom@32:         """
terom@32:             Looks up a template based on the bare "name", which does not include the path or file extension
terom@32:         """
terom@32:         
terom@32:         try :
terom@32:             return self.get_template("%s.%s" % (name, self.fileext))
terom@8: 
terom@32:         except :
terom@71:             raise TemplateError("name=%r: %s" % (name, fmt_mako_exception()))
terom@32:     
terom@40:     def render (self, name, **params) :
terom@32:         """
terom@32:             Render a template, using lookup() on the given name
terom@32:         """
terom@32: 
terom@42:         return self._render(self.lookup(name), self.env, params)
terom@32: 
terom@40:     def render_to_response (self, name, **params) :
terom@40:         """
terom@40:             Render a template, returning a http.Response object
terom@40:         """
terom@40: 
terom@40:         return http.Response(self.render(name, **params))
terom@40: 
terom@50:     def load (self, path) :
terom@32:         """
terom@32:             Loads a template from a specific file
terom@32:         """
terom@32: 
terom@32:         try :
terom@32:             return Template(filename=path, module_directory=CACHE_DIR)
terom@32: 
terom@32:         except :
terom@71:             raise TemplateError("path=%r: %s" % (path, fmt_mako_exception()))
terom@32:     
terom@50:     def render_file (self, path, **params) :
terom@32:         """
terom@42:             Render a template, using load() on the given path. No global environment vars are defined for the render.
terom@32:         """
terom@32: 
terom@50:         return self._render(self.load(path), dict(), params)
terom@32: 
terom@50:     def render_template (self, template, **params) :
terom@42:         """
terom@42:             Render the given template object. No global environment vars are defined for the render.
terom@42:         """
terom@42:         
terom@50:         return self._render(template, dict(), params)
terom@50: