parser.py

# -*- coding: utf-8 -*-
from __future__ import absolute_import, print_function

from flask import Flask, render_template, request
from jinja2 import Environment, meta, exceptions
from random import choice
from inspect import getmembers, isfunction
import logging
import logging.handlers
import json
import yaml
import config


app = Flask(__name__)


def get_custom_filters():
    import filters
    custom_filters = {}
    for m in getmembers(filters):
        if m[0].startswith('filter_') and isfunction(m[1]):
            filter_name = m[0][7:]
            custom_filters[filter_name] = m[1]

    return custom_filters


@app.route("/")
def home():
    return render_template('index.html', custom_filters=get_custom_filters())


@app.route('/convert', methods=['GET', 'POST'])
def convert():
    jinja2_env = Environment()

    # Load custom filters
    custom_filters = get_custom_filters()
    app.logger.debug('Add the following customer filters to Jinja environment: %s' % ', '.join(custom_filters.keys()))
    jinja2_env.filters.update(custom_filters)

    # Load the template
    try:
        jinja2_tpl = jinja2_env.from_string(request.form['template'])
    except (exceptions.TemplateSyntaxError, exceptions.TemplateError) as e:
        return "Syntax error in jinja2 template: {0}".format(e)


    dummy_values = [ 'Lorem', 'Ipsum', 'Amet', 'Elit', 'Expositum',
        'Dissimile', 'Superiori', 'Laboro', 'Torquate', 'sunt',
    ]
    values = {}
    if bool(int(request.form['dummyvalues'])):
        # List template variables (introspection)
        vars_to_fill = meta.find_undeclared_variables(jinja2_env.parse(request.form['template']))

        for v in vars_to_fill:
            values[v] = choice(dummy_values)
    else:
        # Check JSON for errors
        if request.form['input_type'] == "json":
            try:
                values = json.loads(request.form['values'])
            except ValueError as e:
                return "Value error in JSON: {0}".format(e)
        # Check YAML for errors
        elif request.form['input_type'] == "yaml":
            try:
                values = yaml.load(request.form['values'])
            except (ValueError, yaml.parser.ParserError, TypeError) as e:
                return "Value error in YAML: {0}".format(e)
        else:
            return "Undefined input_type: {0}".format(request.form['input_type'])

    # If ve have empty var array or other errors we need to catch it and show
    try:
        rendered_jinja2_tpl = jinja2_tpl.render(values)
    except (ValueError, TypeError) as e:
        return "Error in your values input filed: {0}".format(e)

    if bool(int(request.form['showwhitespaces'])):
        # Replace whitespaces with a visible character (will be grayed with javascript)
        rendered_jinja2_tpl = rendered_jinja2_tpl.replace(' ', u'•')

    return rendered_jinja2_tpl.replace('\n', '<br />')


if __name__ == "__main__":
    # Set up logging
    app.logger.setLevel(logging.__getattribute__(config.LOGGING_LEVEL))
    file_handler = logging.handlers.RotatingFileHandler(filename=config.LOGGING_LOCATION, maxBytes=10*1024*1024, backupCount=5)
    file_handler.setFormatter(logging.Formatter(config.LOGGING_FORMAT))
    file_handler.setLevel(logging.__getattribute__(config.LOGGING_LEVEL))
    app.logger.addHandler(file_handler)

    app.run(
        host=config.HOST,
        port=config.PORT,
        debug=config.DEBUG,
    )