Files
shopdb-flask/plugins/guides/models/guide.py

189 lines
7.6 KiB
Python

"""Guides: step-by-step procedures written and read inside ShopDB.
WHY THIS IS NOT THE KNOWLEDGE BASE PLUGIN
The knowledgebase plugin is a LINK REGISTRY - a short description, a URL and
some keywords, pointing at a document that lives somewhere else. That is a
different job. This holds the document itself.
WHY BLOCKS RATHER THAN A BLOB OF HTML
A guide is stored as an ordered list of typed blocks, each with a stable id,
serialized as JSON. Free-form HTML would be easier to write and would defeat
three of the four things this feature exists for:
checklists a tickable step has to be identifiable to be remembered, and
an <input> buried in pasted markup has no identity
dark mode pasted content carries hardcoded colours, which then fight the
theme - black text on a dark background, and nobody can say
why
printing print has to know where a step begins and ends to avoid
splitting one across a page
Blocks also mean a new block type later is additive: old guides keep
rendering, because the renderer skips what it does not know.
INLINE TEXT IS A RESTRICTED MARKDOWN SUBSET - bold, italic, inline code, links,
line breaks, and nothing else. No fonts, sizes or colours: emphasis is semantic
and the theme decides how it looks. That single rule is what keeps a guide
written next year looking like one written today, and what makes dark mode work
without an author thinking about it.
"""
import json
from datetime import datetime
from shopdb.api import db
from shopdb.core.models.base import BaseModel
def _utcnow():
return datetime.utcnow()
# Block types the renderer knows. Stored as data, not as markup, so the same
# guide can render to screen, to dark mode and to paper differently.
BLOCKTYPES = (
'heading',
'paragraph',
'step', # a numbered step, with its own body
'checklist', # tickable items - the reason progress is a feature
'bullets',
'numbers',
'callout', # info / warning / success, per the KB house style
'code',
'image',
'table',
)
class Guide(BaseModel):
"""One guide. Blocks live in a JSON column rather than a child table.
A guide is edited and saved WHOLE - nobody reorders one paragraph in
isolation - so a child table would buy ordering machinery, a second
migration and N+1 reads, in exchange for nothing this feature needs. The
same reasoning the geenforce manifests and backup payloads already follow.
"""
__tablename__ = 'guides'
guideid = db.Column(db.Integer, primary_key=True)
# Human title, and the slug the URL uses. The slug is stored rather than
# derived on read so an edited title cannot silently break a link somebody
# pasted into a work order.
title = db.Column(db.String(300), nullable=False)
slug = db.Column(db.String(300), nullable=False, unique=True, index=True)
# One line, shown in the list and in search results.
summary = db.Column(db.String(1000))
# Comma-separated, matching how knowledgebase.keywords already works, so one
# search can cover both and there is one tag vocabulary rather than two.
tags = db.Column(db.String(500))
# 'draft' or 'published'. A draft is visible to people who can edit, and
# invisible to everyone else: a half-written procedure on a shop floor is
# worse than no procedure.
status = db.Column(db.String(20), nullable=False, default='draft', index=True)
# MEDIUMTEXT: serialized blocks. Text rather than a native JSON column so the
# bytes come back exactly as written and a diff between versions is stable -
# the same reason the backups plugin stores its projection as text.
blocksjson = db.Column(db.Text(length=16777215), nullable=False, default='[]')
createdby = db.Column(db.Integer, db.ForeignKey('users.userid'))
updatedby = db.Column(db.Integer, db.ForeignKey('users.userid'))
createdat = db.Column(db.DateTime, nullable=False, default=_utcnow)
updatedat = db.Column(db.DateTime, nullable=False, default=_utcnow,
onupdate=_utcnow)
publishedat = db.Column(db.DateTime)
# Bumped on every save. Cheap, and it gives a printed copy something
# honest to put in its footer: "version 7, printed 26 Aug 2026".
revision = db.Column(db.Integer, nullable=False, default=1)
@property
def blocks(self):
"""The decoded block list, or [] on a corrupt row.
Deliberately forgiving, unlike the backups payload getter: a guide that
will not render is a page a person cannot read, and an empty guide with
its title and tags intact is a better failure than an error page. The
corruption is still visible - the editor shows no blocks.
"""
if not self.blocksjson:
return []
try:
data = json.loads(self.blocksjson)
except (ValueError, TypeError):
return []
return data if isinstance(data, list) else []
@blocks.setter
def blocks(self, value):
self.blocksjson = json.dumps(value or [], separators=(',', ':'))
def taglist(self):
"""Tags as a clean list, empties dropped."""
return [t.strip() for t in (self.tags or '').split(',') if t.strip()]
def to_dict(self, includeblocks=False):
data = {
'guideid': self.guideid,
'title': self.title,
'slug': self.slug,
'summary': self.summary,
'tags': self.taglist(),
'status': self.status,
'revision': self.revision,
'createdat': self.createdat.isoformat() + 'Z' if self.createdat else None,
'updatedat': self.updatedat.isoformat() + 'Z' if self.updatedat else None,
'publishedat': (self.publishedat.isoformat() + 'Z'
if self.publishedat else None),
}
if includeblocks:
data['blocks'] = self.blocks
return data
class GuideImage(BaseModel):
"""An image pasted or dropped into a guide.
Bytes live in the database, not on disk. Guides are small, the images are
screenshots rather than photographs, and a row travels with a database
backup - whereas a file under instance/ has been lost to a container rebuild
on this very deployment before. If a site ever puts thousands of these in,
the storage decision is one column and one route to revisit.
"""
__tablename__ = 'guideimages'
guideimageid = db.Column(db.Integer, primary_key=True)
# Nullable: an image is uploaded while a NEW guide is still unsaved, so it
# exists before the guide it belongs to does. The editor attaches it on
# save; anything still unattached is orphaned and prunable.
guideid = db.Column(db.Integer, db.ForeignKey('guides.guideid',
ondelete='CASCADE'), index=True)
filename = db.Column(db.String(255))
mimetype = db.Column(db.String(100), nullable=False)
bytesize = db.Column(db.Integer, nullable=False)
data = db.Column(db.LargeBinary(length=(2 ** 24) - 1), nullable=False)
uploadedby = db.Column(db.Integer, db.ForeignKey('users.userid'))
createdat = db.Column(db.DateTime, nullable=False, default=_utcnow)
def to_dict(self):
return {
'guideimageid': self.guideimageid,
'guideid': self.guideid,
'filename': self.filename,
'mimetype': self.mimetype,
'bytesize': self.bytesize,
'url': '/api/guides/images/{}'.format(self.guideimageid),
'createdat': self.createdat.isoformat() + 'Z' if self.createdat else None,
}