__init__.py 2.78 KB
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import json
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import logging
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import os
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import re
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from pathlib import Path

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import cachecontrol
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import flask
import jinja2
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import pkg_resources
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import requests
import tableschema
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from commonmark import commonmark
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import opendataschema

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from . import config
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log = logging.getLogger(__name__)

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def generate_schema_from_url_func(session):
    """Generates a function that encloses session"""

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    def tableschema_from_url(url):
        response = session.get(url)
        response.raise_for_status()
        descriptor = response.json()
        return tableschema.Schema(descriptor)
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    return tableschema_from_url


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def is_http_url(ref) -> bool:
    return isinstance(ref, str) and re.match("https?://", ref)


class SchemaCatalogRegistry:
    """Retain section_name -> catalog url matching
    and creates SchemaCatalog instance on demand"""

    def __init__(self, session):
        self.session = session
        self.url_map = {}

    def add_ref(self, name, url):
        self.url_map[name] = url

    def build_schema_catalog(self, name):
        if name in self.url_map:
            catalog_url = self.url_map[name]
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            try:
                catalog = opendataschema.SchemaCatalog(catalog_url, session=self.session)
            except requests.exceptions.RequestException as exc:
                log.exception(exc)
                return None
            return catalog
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        return None


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caching_session = cachecontrol.CacheControl(requests.Session())
tableschema_from_url = generate_schema_from_url_func(caching_session)
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# And load schema catalogs which URLs are found in homepage_config.json
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schema_catalog_registry = SchemaCatalogRegistry(caching_session)
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if config.HOMEPAGE_CONFIG:
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    log.info("Initializing homepage sections...")
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    for section in config.HOMEPAGE_CONFIG['sections']:
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        name = section['name']
        log.info('Initializing homepage section "{}"...'.format(name))
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        catalog_ref = section.get('catalog')
        if is_http_url(catalog_ref):
            schema_catalog_registry.add_ref(name, catalog_ref)
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    log.info("...done")
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# Flask things
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app = flask.Flask(__name__)
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app.secret_key = config.SECRET_KEY

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# Jinja2 url_quote_plus custom filter
# https://stackoverflow.com/questions/12288454/how-to-import-custom-jinja2-filters-from-another-file-and-using-flask
blueprint = flask.Blueprint('filters', __name__)

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@jinja2.contextfilter
@blueprint.app_template_filter()
def commonmark2html(context, value):
    return commonmark(value)


app.register_blueprint(blueprint)


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@app.context_processor
def inject_version():
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    return {"validata_ui_version": pkg_resources.get_distribution("validata-ui").version}
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@app.context_processor
def inject_config():
    return {"config": config}


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# Keep this import after app initialisation (to avoid cyclic imports)
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from . import views  # noqa isort:skip