#! /usr/bin/env python
# -*- coding: utf-8 -*-
# vim:fenc=utf-8
#
# Copyright © 2017 lafrite <lafrite@Poivre>
#
# Distributed under terms of the MIT license.

"""
Expression

"""
from ..core import tree2txt, tree2tex

class Render(object):
    """ Object which render Expression or token """

    def __init__(self, default="txt"):
        self._default = default
        self._render = default
        self.renders = {}

    def register_render(self, name, func, attribute):
        """ register a render """
        try:
            self.renders[name]
        except KeyError:
            self.renders[name] = {"name": name, "func": func, "attribute": attribute}
        else:
            raise ValueError("This render name already exists")

    @property
    def render_name(self):
        return self._render

    @property
    def render(self):
        return self.renders[self._render]

    def __call__(self, mo_tree, tmp_render=''):
        if tmp_render:
            r = self.renders[tmp_render]
        else:
            r = self.render

        try:
            return r["func"](mo_tree)
        except ValueError:
            pass

        try:
            return getattr(mo_tree, r["attribute"])
        except AttributeError:
            return str(mo_tree)

    def set_render(self, render):
        """ Define the render """
        if render in self.renders.keys():
            self._render = render
        else:
            raise ValueError("This render does not exists")



render = Render()
render.register_render("txt", tree2txt, "__txt__")
render.register_render("tex", tree2tex, "__tex__")

# -----------------------------
# Reglages pour 'vim'
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# cursor: 16 del