Cannot print data from database using the new version - google-app-engine

I am using the latest version of web.py.
I am trying to print data from the database to a webpage.
The code i use is the following
import web
from google.appengine.ext import db
from models import *
urls = (
'/', 'index',
)
render = web.template.render('templates', base='base')
class index:
def GET(self):
votes = db.GqlQuery("SELECT * FROM votes")
return render.index(votes)
app = web.application(urls, globals())
main = app.cgirun()
the template is the following
$def with(votes)
$for vote in votes:
<li>$vote.status</li>
and i am getting this when i run it
[<models.votes object at 0x0000000004525F28>]
Is this a bug with the new version cause in previous version it works.
I forgot to say that i am compiling my templates as stated here.

It works on my machine, running the latest web.py 0.36 with this code:
main.py
import web
from google.appengine.ext import db
class Votes(db.Model):
status = db.StringProperty()
urls = (
'/', 'Index',
)
render = web.template.render('templates', base='base')
class Index:
def GET(self):
vote = Votes()
vote.status ="foo"
vote.put()
votes = db.GqlQuery("SELECT * FROM Votes")
return render.index(votes)
app = web.application(urls, globals())
main = app.cgirun()
templates/index.html
$def with(votes)
$for vote in votes:
<li>$vote.status</li>
templates/base.html
$def with (content)
<html>
<head>
</head>
<body>
$:content
</body>
</html>
this is the result:
foo

I don't use web.py; but maybe it doesn't support generators/iterables in the templates as expected. Try fetching the results first by changing your line to:
votes = db.GqlQuery("SELECT * FROM votes").fetch(100)

Related

Stuck at django models get_absolute_url. NoReverseMatch

Its not redirecting and giving the error of NoReverseMatch. exception is: book_detail cannot be found... though i have the correct name and same name in urls.py and template. Even book_detail anchored to the book_list working completely fine. where am i doing the mistake kindly help me.
Details:
[Error]
NoReverseMatch at /catalog/book_create/
Reverse for 'book_detail' not found. 'book_detail' is not a valid view function or pattern name.
Request Method: POST
Request URL: http://127.0.0.1:8000/catalog/book_create/
Django Version: 4.1.3
Exception Type: NoReverseMatch
Exception Value:
Reverse for 'book_detail' not found. 'book_detail' is not a valid view function or pattern name.
Exception Location: C:\Users\Umar\AppData\Local\Programs\Python\Python311\Lib\site-packages\django\urls\resolvers.py, line 828, in _reverse_with_prefix
Raised during: catalog.views.BookCreateView
Python Executable: C:\Users\Umar\AppData\Local\Programs\Python\Python311\python.exe
Python Version: 3.11.0
Python Path:
['C:\Users\Umar\Djano_learning\Django\my_site',
'C:\Users\Umar\AppData\Local\Programs\Python\Python311\python311.zip',
'C:\Users\Umar\AppData\Local\Programs\Python\Python311\Lib',
'C:\Users\Umar\AppData\Local\Programs\Python\Python311\DLLs',
'C:\Users\Umar\AppData\Local\Programs\Python\Python311',
'C:\Users\Umar\AppData\Local\Programs\Python\Python311\Lib\site-packages']
Server time: Mon, 02 Jan 2023 17:02:23 +0000
Models:
class Book(models.Model):
title = models.CharField(max_length=100)
'''Linking Author class model to Book model'''
author = models.ForeignKey('Author',on_delete=models.SET_NULL,null=True)
summary = models.TextField(max_length=600)
isbn = models.CharField(max_length=13, unique=True)
genre = models.ManyToManyField(Genre)
language =
models.ForeignKey('Language',on_delete=models.RESTRICT,null=True)
def __str__(self):
return self.title
def get_absolute_url(self):
return reverse('book_detail', kwargs={'pk' : self.pk})
[Book_detail.html]
<html lang="en">
<head>
</head>
<body>
<h2>Details of Books</h2>
<h2>{{book}}</h2>
<h2>{{author}}</h2>
</body>
</html>
[Urls.py]
from django.urls import path,reverse_lazy,reverse
from .views import (HomeView,BookListView,
BookCreateView,BookDetailView,AuthorCreateView,AuthorListView,
AuthorDetailView)
from . import views
app_name='catalog'
# path is below
urlpatterns = [
path('',HomeView.as_view(),name='home'),
path('book_list/',BookListView.as_view(),name='book_list'),
path('book_create/',BookCreateView.as_view(),name='book_create'),
**path('book_detail/<int:pk>/',BookDetailView.as_view(),name='book_detail'),**
path('author_create/',AuthorCreateView.as_view(),name='author_create'),
path('author_list/',AuthorListView.as_view(),name='author_list'), path('author_detail/<int:pk>/',AuthorDetailView.as_view(),name='people_detail')
,path('view/',views.auth_check,name='view')
]
A simple Redirect should have to work.

How To Migrate RichTextField to StreamField?

In my blog post model I am trying to migrate a RichTextField to a StreamField. I have followed the Wagtail docs "Migrating RichTextFields to StreamField" including the section on migrating blog posts with revisions. They were not effective. How do I turn a RichTextField into a StreamField?
This is for a blog using Django 1.11.13, Wagtail 2.1 and PostgreSQL. I have over 200 blog posts, many of them with the Live+Draft status meaning they have unpublished revisions. I inspected the blog posts in the database, it looks like their body fields are stored as HTML.
I copied over the code from the docs and changed all references to relate to my own project. Upon running migrate, I got an AttributeError that "raw_text" is not found. So I created an exception to pass over it. I applied the migration and it completed with an OK.
Then in models.py I changed my class's body attribute from a RichTextField to a StreamField with a RichFieldBlock. I also changed its content panel from a FieldPanel to a StreamFieldPanel. I applied this migration and it completed with an OK.
When I viewed some posts in Wagtail admin, all the posts with a Live+Draft status were converted to RichTextBlocks inside StreamFields, however, their content was wrapped inside a JSON object called {'rich_text': ''}. The JSON object was not styled like the rest of the text inside the editor. When I viewed those posts live no data showed up, I assume because the template could't read JSON. All the blog posts with a Live status also had the RichTextField converted to StreamField, but their content was empty. Their data was erased from the editor. When I viewed them live they were blank. However, when I inspect them in the database their body fields still contain the previous HTML that I saw.
This is a Live+Draft post in admin:
This is a Live post in admin:
I tried to install a fresh copy of the database after I ran the two migrations and was seeing odd data, and that didn't improve things.
template.html:
<section>
{{ page.body }}
</section>
models.py before I ran the conversion migration:
class BlogPost(Page):
body = RichTextField(blank=True)
content_panels = Page.content_panels + [
FieldPanel('body'),
]
migration.py, I added an exception for the AttributeError within the page_to_streamfield() function because raw_text was not found:
# -*- coding: utf-8 -*-
# Generated by Django 1.11.13 on 2019-05-01 13:46
from __future__ import unicode_literals
import json
from django.core.serializers.json import DjangoJSONEncoder
from django.db import migrations, models
from wagtail.core.rich_text import RichText
def page_to_streamfield(page):
changed = False
try:
if page.body.raw_text and not page.body:
page.body = [('rich_text', {'rich_text': RichText(page.body.raw_text)})]
changed = True
except AttributeError:
pass
return page, changed
def pagerevision_to_streamfield(revision_data):
changed = False
body = revision_data.get('body')
if body:
try:
json.loads(body)
except ValueError:
revision_data['body'] = json.dumps(
[{
"value": {"rich_text": body},
"type": "rich_text"
}],
cls=DjangoJSONEncoder)
changed = True
else:
# It's already valid JSON. Leave it.
pass
return revision_data, changed
def page_to_richtext(page):
changed = False
if page.body.raw_text is None:
raw_text = ''.join([
child.value['rich_text'].source for child in page.body
if child.block_type == 'rich_text'
])
page.body = raw_text
changed = True
return page, changed
def pagerevision_to_richtext(revision_data):
changed = False
body = revision_data.get('body', 'definitely non-JSON string')
if body:
try:
body_data = json.loads(body)
except ValueError:
# It's not apparently a StreamField. Leave it.
pass
else:
raw_text = ''.join([
child['value']['rich_text'] for child in body_data
if child['type'] == 'rich_text'
])
revision_data['body'] = raw_text
changed = True
return revision_data, changed
def convert(apps, schema_editor, page_converter, pagerevision_converter):
BlogPage = apps.get_model("blog", "BlogPost")
for page in BlogPage.objects.all():
page, changed = page_converter(page)
if changed:
page.save()
for revision in page.revisions.all():
revision_data = json.loads(revision.content_json)
revision_data, changed = pagerevision_converter(revision_data)
if changed:
revision.content_json = json.dumps(revision_data, cls=DjangoJSONEncoder)
revision.save()
def convert_to_streamfield(apps, schema_editor):
return convert(apps, schema_editor, page_to_streamfield, pagerevision_to_streamfield)
def convert_to_richtext(apps, schema_editor):
return convert(apps, schema_editor, page_to_richtext, pagerevision_to_richtext)
class Migration(migrations.Migration):
dependencies = [
# leave the dependency line from the generated migration intact!
('blog', 'previous_migration'),
]
operations = [
migrations.RunPython(
convert_to_streamfield,
convert_to_richtext,
),
]
models.py after running the previous migration, I manually changed it to a StreamField and ran a second migration for just this change:
class BlogPost(Page):
body = StreamField([
('rich_text', blocks.RichTextBlock())
], blank=True)
content_panels = Page.content_panels + [
StreamFieldPanel('body'),
]
I expected to see a blog post's data inside a StreamField within Wagtail admin, but instead it was blank or wrapped in a JSON object.
I was able to migrate a RichTextField to StreamField with a RichTextBlock with this script (this assumes a schema that looks like the first 3 chapters of the Wagtail Getting Started tutorial). I found that it was easier to think about this process by breaking it into distinct steps: fresh db from backup/make backup, schema migration, data migration, and admin/template alterations. I found that I needed to loop through each BlogPost and all of its associated PageRevision. Editing the live published data was straightforward, but the drafts are stored as serialized JSON two levels deep, which was tricky to figure out how to interact with. Hopefully this script helps others. Note: this script doesn't migrate in reverse.
0004_convert_data.py
import json
from django.db import migrations
import wagtail.core.fields
from wagtail.core.rich_text import RichText
def convert_data(apps, schema_editor):
blog_page = apps.get_model('blog', 'BlogPage')
for post in blog_page.objects.all():
print('\n', post.title)
# edit the live post
if post.body.raw_text and not post.body:
post.body = [('paragraph', RichText(post.body.raw_text))]
print('Updated ' + post.title)
post.save()
# edit drafts associated with post
if post.has_unpublished_changes:
print(post.title + ' has drafts...')
for rev in post.revisions.all():
data = json.loads(rev.content_json)
body = data['body']
print(body)
print('This is current JSON:', data, '\n')
data['body'] = json.dumps([{
"type": "paragraph",
"value": body
}])
rev.content_json = json.dumps(data)
print('This is updated JSON:', rev.content_json, '\n')
rev.save()
print('Completed ' + post.title + '.' + '\n')
class Migration(migrations.Migration):
dependencies = [
('blog', '0003_blogpage_stream'),
]
operations = [
migrations.AlterField(
model_name='blogpage',
name='body',
field=wagtail.core.fields.StreamField([('paragraph', wagtail.core.blocks.RichTextBlock())], blank=True),
),
migrations.RunPython(convert_data),
]
models.py
from django.db import models
from wagtail.core.models import Page
from wagtail.core import blocks
from wagtail.core.fields import RichTextField, StreamField
from wagtail.admin.edit_handlers import FieldPanel, StreamFieldPanel
from wagtail.images.blocks import ImageChooserBlock
from wagtail.search import index
class BlogIndexPage(Page):
intro = RichTextField(blank=True)
content_panels = Page.content_panels + [
FieldPanel('intro', classname="full")
]
class BlogPage(Page):
date = models.DateField("Post date")
intro = models.CharField(max_length=250)
# body = RichTextField(blank=True)
body = StreamField([
('paragraph', blocks.RichTextBlock()),
], blank=True)
stream = StreamField([
('heading', blocks.CharBlock(classname="full title")),
('paragraph', blocks.RichTextBlock()),
('image', ImageChooserBlock()),
], blank=True)
search_fields = Page.search_fields + [
index.SearchField('intro'),
index.SearchField('body'),
]
content_panels = Page.content_panels + [
FieldPanel('date'),
FieldPanel('intro'),
StreamFieldPanel('body'),
StreamFieldPanel('stream'),
]
templates/blog/blog_page.html
{% extends "base.html" %}
{% load wagtailcore_tags %}
{% block body_class %}template-blogpage{% endblock %}
{% block content %}
<h1>{{ page.title }}</h1>
<p class="meta">{{ page.date }}</p>
<div class="intro">{{ page.intro }}</div>
{{ page.body }}
<p>Return to blog</p>
{% endblock %}

Displaying Python database on Flask web server

I'm working on a project that requires that I create a create a database, import data into it, and display it on a FLASK local server. I've created the database, but I'm confused as to what I need to do in order to display its tables on the server. I have it set up to display information via HTML through render_template and believe I've established a connection via config.py, but I'm not sure where to go from here. I've read the following guides, but I don't quite understand them. If anybody could assist, I would appreciate it.
http://flask.pocoo.org/docs/0.12/patterns/sqlalchemy/
http://flask-sqlalchemy.pocoo.org/2.3/config/
Below are the relevant files in the project root.
/project
config.py
database_insert.py
server.py
/app
/templates
index.html
__init__.py
models.py
routes.py
config.py
import os
basedir = os.path.abspath(os.path.dirname(__file__))
class Config(object):
SECRET_KEY = 'you-will-never-guess'
app.config['SQLALCHEMY_DATABASE_URI'] = 'sqlite:////project/app.db'
SQLALCHEMY_TRACK_MODIFICATIONS = False
init.py
from flask import Flask, request, render_template
from config import Config
from flask_sqlalchemy import SQLAlchemy
from flask_migrate import Migrate
app = Flask(__name__)
app.config.from_object(Config)
db = SQLAlchemy(app)
migrate = Migrate(app, db)
from app import routes, models
models.py
from app import db
class Lot(db.Model):
id = db.Column(db.Integer, primary_key=True)
title = db.Column(db.String(64), index=True)
spots = db.relationship('Spot', backref='author', lazy='dynamic')
def __repr__(self):
return '<Lot {}>'.format(self.username)
class Spot(db.Model):
id = db.Column(db.Integer, primary_key=True)
availability = db.Column(db.String(140))
spot_num = db.Column(db.String(140))
lot_id = db.Column(db.Integer, db.ForeignKey('lot.id'))
def __repr__(self):
return '<Spot {}>'.format(self.body)
routes.py
from app import app
from flask import Flask, request, render_template
#app.route('/')
#app.route('/index')
def index():
lot_details = {
'id': 'TEST_ID', #placeholder for testing purposes
'title': 'TEST_TITLE' #placeholder for testing purposes
}
return render_template('index.html', lot=lot_details)
index.html
<!DOCTYPE html>
<html>
<head>
<title>test</title>
</head>
<body>
<p>Hello, World!</p>
<p>{{lot.id}}</p>
<p>{{lot.title}}</p>
</body>
At first, define helper method in your Spot model class.
class Spot(db.Model):
id = db.Column(db.Integer, primary_key=True)
availability = db.Column(db.String(140))
spot_num = db.Column(db.String(140))
lot_id = db.Column(db.Integer, db.ForeignKey('lot.id'))
def __repr__(self):
return '<Spot {}>'.format(self.body)
def dump(self):
return dict(id=self.id, title=self.title)
Then, in your flask route, you may query:
#app.route('/')
#app.route('/index')
def index():
lot_details = Lot.query.first().dump() # query first item
return render_template('index.html', lot=lot_details)

GAE upload image then dynamically serve the image

I'm trying to make a simple app on GAE that allows a user to enter a url to an image and a name. The app then uploads this image to the Datastore along with its name.
After the upload the page self redirects and then should send the image back to the client and display it on their machine.
After running all I get is a Server error. Since I am new to GAE please could someone tell me if my code is at least correct.
I can't see what is wrong with my code. (I have checked for correct indentation and whitespace). Below is the code:
The python:
import jinja2 # html template libary
import os
jinja_environment = jinja2.Environment(
loader=jinja2.FileSystemLoader(os.path.dirname(__file__)))
import urllib
import urllib2
import webapp2
from google.appengine.ext import db
from google.appengine.api import urlfetch
class Default_tiles(db.Model):
name = db.StringProperty()
image = db.BlobProperty(default=None)
class MainPage(webapp2.RequestHandler):
def get(self):
template = jinja_environment.get_template('index.html')
self.response.out.write(template.render())
class Upload(webapp2.RequestHandler):
def post(self):
# get information from form post upload
image_url = self.request.get('image_url')
image_name = self.request.get('image_name')
# create database entry for uploaded image
default_tile = Default_tiles()
default_tile.name = image_name
default_tile.image = db.Blob(urlfetch.Fetch(image_url).content)
default_tile.put()
self.redirect('/?' + urllib.urlencode({'image_name': image_name}))
class Get_default_tile(webapp.RequestHandler):
def get(self):
name = self.request.get('image_name')
default_tile = get_default_tile(name)
self.response.headers['Content-Type'] = "image/png"
self.response.out.write(default_tile.image)
def get_default_tile(name):
result = db.GqlQuery("SELECT * FROM Default_tiles WHERE name = :1 LIMIT 1", name).fetch(1)
if (len(result) > 0):
return result[0]
else:
return None
app = webapp2.WSGIApplication([('/', MainPage),
('/upload', Upload),
('/default_tile_img', Get_default_tile)],
debug=True)
The HTML:
<html>
<head>
<link type="text/css" rel="stylesheet" href="/stylesheets/main.css" />
</head>
<body>
<form action="/upload" method="post">
<div>
<p>Name: </p>
<input name="image_name">
</div>
<div>
<p>URL: </p>
<input name="image_url">
</div>
<div><input type="submit" value="Upload Image"></div>
</form>
<img src="default_tile_img?{{ image_name }}">
</body>
</html>
Any help at all will be so much appreciated. Thanks you!
UPDATE
Thanks to Greg, I know know how to view error logs. As Greg said I was missing a comma, I have updated the code above.
The app now runs, but when I upload an image, no image shows on return. I get the following message in the log:
File "/Users/jamiefearon/Desktop/Development/My Programs/GAE Fully functional website with css, javascript and images/mywebsite.py", line 53, in get
default_tile = self.get_default_tile(name)
TypeError: get_default_tile() takes exactly 1 argument (2 given)
I only passed one argument to get_default_tile() why does it complain that I passed two?
You're missing a comma after ('/upload', Upload) in the WSGIApplication setup.
use this python code
import jinja2 # html template libary
import os
jinja_environment = jinja2.Environment(
loader=jinja2.FileSystemLoader(os.path.dirname(__file__)))
import urllib
import urllib2
import webapp2
from google.appengine.ext import db
from google.appengine.api import urlfetch
class Default_tiles(db.Model):
name = db.StringProperty()
image = db.BlobProperty(default=None)
class MainPage(webapp2.RequestHandler):
def get(self):
template = jinja_environment.get_template('index.html')
self.response.out.write(template.render())
class Upload(webapp2.RequestHandler):
def post(self):
# get information from form post upload
image_url = self.request.get('image_url')
image_name = self.request.get('image_name')
# create database entry for uploaded image
default_tile = Default_tiles()
default_tile.name = image_name
default_tile.image = db.Blob(urlfetch.Fetch(image_url).content)
default_tile.put()
self.redirect('/?' + urllib.urlencode({'image_name': image_name}))
class Get_default_tile(webapp2.RequestHandler):
def get_default_tile(self, name):
result = db.GqlQuery("SELECT * FROM Default_tiles WHERE name = :1 LIMIT 1", name).fetch(1)
if (len(result) > 0):
return result[0]
else:
return None
def get(self):
name = self.request.get('image_name')
default_tile = self.get_default_tile(name)
self.response.headers['Content-Type'] = "image/png"
self.response.out.write(default_tile)
app = webapp2.WSGIApplication([('/', MainPage),
('/upload', Upload),
('/default_tile_img', Get_default_tile)],
debug=True)

Integrating Chat with (webapp2 + python 2.7 + Jinja2)

I'm trying to add chat to my site and am integrating some code with my existing code. The chat app works fine on its own when it's all set up in the original main.app file. But when I try to move that same code to a handlers.py file and then setup up routes in routes.py I get errors saying template variables are undefined. Are the two different codes conflicting in the way they render templates? They seem to be using webapp2 differently, i.e. my code renders templates like this:
self.render_template('secure_zone.html', **params)
And the chat app like this:
self.response.out.write(render("main.html",
username=username,
usernameerror=usernameerror,
channel=channelname,
channelerror=channelerror))
Are both acceptable?
Here's my handlers.py file:
Routes are setup in routes.py and added in main.py
"""
import httpagentparser
from boilerplate import models
from boilerplate.lib.basehandler import BaseHandler
from boilerplate.lib.basehandler import user_required
class SecureRequestHandler(BaseHandler):
"""
Only accessible to users that are logged in
"""
#user_required
def get(self, **kwargs):
user_session = self.user
user_session_object = self.auth.store.get_session(self.request)
user_info = models.User.get_by_id(long( self.user_id ))
user_info_object = self.auth.store.user_model.get_by_auth_token(
user_session['user_id'], user_session['token'])
try:
params = {
"user_session" : user_session,
"user_session_object" : user_session_object,
"user_info" : user_info,
"user_info_object" : user_info_object,
"userinfo_logout-url" : self.auth_config['logout_url'],
}
return self.render_template('secure_zone.html', **params)
except (AttributeError, KeyError), e:
return "Secure zone error:" + " %s." % e
Here's the main.py file for the chat app:
import os
import hashlib
import urllib
import logging
import re
import json
import webapp2
import jinja2
from google.appengine.api import channel as channel_api # 'channel' is kind of ambiguous in context
from google.appengine.ext import db
from google.appengine.api import memcache
# This section will eventually get moved to a Handler class
template_dir = os.path.join(
os.path.dirname(__file__), 'templates')
jinja_env = jinja2.Environment(
loader = jinja2.FileSystemLoader(template_dir),
autoescape = True)
def render_str(template, **params):
'''Returns a string of the rendered template'''
t = jinja_env.get_template(template)
return t.render(params)
def render(template, **kw):
'''Render using the template and parameters'''
return(render_str(template, **kw))
# End Handler
class Main(webapp2.RequestHandler):
def get(self):
'''Show connection page'''
return self.render_template("main.html", channel="#udacity")
def post(self):
'''Displays chat UI'''
username = self.request.get('username')
channelname = self.request.get('channel')
usernameerror = ""
if not username:
usernameerror="Please enter a username"
elif not re.compile(r'^[a-zA-Z0-9_-]{3,20}$').match(username):
usernameerror = "Username must consist of 3-20 alphanumeric characters."
elif get_user(username):
usernameerror="Username already in use"
channelerror = ""
if channelname and not re.compile(r'^#[\w]{3,20}$').match(channelname):
channelerror="Channel must consist of 3-20 alpha_numeric characters and start with a #"
if len(usernameerror+channelerror) > 0:
self.response.out.write(render("main.html",
username=username,
usernameerror=usernameerror,
channel=channelname,
channelerror=channelerror))
app = webapp2.WSGIApplication([
('/', Main),
('/communication', Communication),
('/_ah/channel/connected/?', Connect),
('/_ah/channel/disconnected/?', Disconnect)
], debug=True)
The specific error you posted in the comments "Error: 'Main' object has no attribute 'render_template'" is because in your Main handler, you try to return self.render_template. You should be just calling the function like this:
render_template("main.html", channel="#udacity")
Please note that I did not check the rest of your code, so if you run into any other issues, please post the specific errors you get.
It is because your webapp2.RequestHandler do not have the corresponding function "render_template"
you can use a BaseHandler with render_template function added to achieve the template rendering
from google.appengine.ext.webapp import template
class BaseHandler(webapp2.RequestHandler):
def render_template(self, filename, **template_args):
path = os.path.join(os.path.dirname(__file__), 'templates', filename)
self.response.write(template.render(path, template_args))
class Main(BaseHandler):
def get(self):
'''Show connection page'''
return self.render_template("main.html", channel="#udacity")
ref: http://blog.notdot.net/2011/11/Migrating-to-Python-2-7-part-2-Webapp-and-templates
I just started using webapp2 + python 2.7 + Jinja2 few days, and that is the same problem I encountered.
Hope this solution can help you ;)

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