shooflenet/articles/__init__.py

"""Route requests for articles according to shoofle's rules.

This is a simple module which is basically entirely here to provide access, in a sensible location,
to the `bloop` object. It's a blueprint which describes how to route requests for articles on my website
(possibly located at http://shoofle.net, possibly not located there). Most of the interesting stuff is in
`render_article`; Go team!"""

import os
from flask import Blueprint, render_template, send_from_directory, abort

folder = "articles"
article_base_template = os.path.join(folder, "article.template.html")
article_small_template = os.path.join(folder, "article.zip.template.html")
bloop = Blueprint("articles", __name__, template_folder="")

@bloop.route("/")
def main_page():
	"""Renders the list of articles/projects."""
	return render_template("project_list.html")

@bloop.route("/.zip/")
def main_page_small():
	return render_template("project_list.zip.html")

@bloop.route("/<article_name>/")
def render_article(article_name):
	"""Renders a requested article! This should always be @routed last, because it catches a 
	wide variety of requests. As a result, other things need to be @routed first, because they 
	might never get called if this catches them first."""
	# Arguably, the various options for how to render (templates, articles, flat html) could be stuck into various 
	# subdirectories. Ultimately I don't want to do this because I want this to be lightweight - this __init__.py file 
	# can be chucked into any folder and start showing pages correctly. But whatever!

	# In the examples, let's think about a request for "example.com/some-article".

	# First, we convert the important part of the requested page into a filename
	# "example.com/Some-Article/" => folder="Some-Article" => file_name = "articles/some_article"
	file_name = os.path.join(folder, article_name.replace("-", "_").lower())

	# Here's the priority list for file rendering!
	if os.path.isfile(file_name + ".template.html"):
		# If the file "articles/some_article.template.html" exists, then there's a specific {template} written 
		# for this path. Specific page {templates} take priority.
		return render_template(file_name + ".template.html")
	if os.path.isfile(file_name + ".article.html"):
		# If "articles/some_article.article.html" exists but there's no template, then we should render that
		# {article fragment}, but using the {article base template}. In the future, this should possibly also
		# extract the title from the {article fragment} and feed it into the {article base template} as well.
		return render_template(article_base_template, target=file_name + ".article.html")
	if file_name.endswith(".zip") and os.path.isfile(file_name[:-4] + ".article.html"):
		return render_template(article_small_template, target=file_name[:-4] + ".article.html")
	if os.path.isfile(file_name + ".html"):
		# If we haven't found any results yet, check to see if "articles/some_article.html" exists. If it does,
		# just display it plain. This also provides a clean way to access the raw form of files like
		# "articles/some_article.template.html" - just make a request for "example.com/some-article.template/"
		# and it will be caught by this rule and rendered.
		return render_template(file_name + ".html")
	if os.path.isfile(file_name):
		# If it didn't match any other rules, then just render the file that has precisely the requested name.
		return render_template(file_name);

	# I *believe* there's one instance that can't be accessed by this kind of routing in any way:
	# If the files "articles/some_article" and "articles/some_article.html" both exist, then no request will
	# convince this blueprint to return the former. However, as sacrifices go, I don't think it's too bad, and 
	# that should be the only case when this happens.

        # It also can't find files with hyphens in their name, because they get replaced with underscores.

	# If we didn't find any files, throw up a 404.

	abort(404)

@bloop.route("/<article_name>/<path:file_path>")
def supplementary(article_name, file_path):
	"""Sends a file such that articles can have supplementary content.

	The article at "example.com/great-articles" will have its article fragment HTML defined at
	"articles/great_articles.article.html" and its supplementary content will be found in the folder
	"articles/great_articles/some_image.jpg".
	
	Oh, and one last thought - if we want more complicated supplementary content behaviors, it might be
	necessary to make a blueprint for it. Then, it's necessary to include the blueprint in this file. Oh well.
	"""
	# Put the article name into the standard form, and concatenate them together.
	article_name = article_name.replace("-", "_").lower()
	
	# You could make a strong argument that this is unnecessary, and we could just shove in a static file handler.
	# But I like this solution more. It better separates out the supplementary content from the article itself.
	# Things that don't fit into this framework might not belong as articles, anyway!

	# Important! This didn't work right for a long time until I finally made it join `folder` to the beginning.
	# Without that, it tries to load the file relative to wherever the server's running - which is /not/ the
	# right thing. The server's running somewhere, but this needs to be in the articles folder, yadda yadda, 
	# you can figure it out.
	path = os.path.join(folder, article_name, file_path)
	# If the path exists and is a file, then we should send it.
	if os.path.isfile(path):
		directory, file_name = os.path.split(path)
		print("sending %(fn)s from directory %(d)s" % {"fn": file_name, "d": directory})
		
		return send_from_directory(directory, file_name)

	# If that file wasn't found, then, well, whoops.
	abort(404)

bloop.route("/<article_name>.zip/<path:file_path>")(supplementary)

"""Th-th-th-that's all, folks!"""