Long time reader, first time poster, please be gentle.
I've been working on a web app using Flask and SQLAlchemy that allows users to review and comment on MMA fights. I have a list of fights in a SQL table appropriately named "fights" and I'm trying to use dynamic routing to filter through the data. I have a list of all the fights on one route like so:
#app.route('/ufc251')
#login_required
def ufc251():
return render_template('ufc251.html', fights=Fight.query.all())
which helped me make a slick page with all the fights listed, and then made another route for info on individual fights like so:
#app.route('/fight/<int:id>')
#login_required
def fight(id):
id = Fight.query.filter_by(id=id).first_or_404()
return render_template('fight.html')
so far, so good. If I click on a fight from the main page i get sent to a url fightsite/fights/<fight_id>, which is perfect. The problem that I'm having is that I can't for the life of me figure out how to call the data from the row for a single fight. If i change my route to:
#app.route('/fight/<int:id>')
#login_required
def fight(id):
id = Fight.query.filter_by(id=id).first_or_404()
return render_template('fight.html', fight=Fight.query.filter_by(id=id).first())
I get the error
sqlalchemy.exc.ArgumentError: Object <Fight 1> is not legal as a SQL literal value
but if i give id a value (i.e. id=1) it will display the data from the first row in my fights table, so i feel like the problem is in the (id=id) part, but after hours of scouring the internet, I can't seem to find a solution.
Any help would be greatly appreciated. And yes, I've read the other StackOverflow article on this subject, however the answer doesn't seem to apply to this situation.
Thank you in advance!
I figured it out, however I decided I'd leave the question in case anybody else has this issue.
i changed:
#app.route('/fight/<int:id>')
#login_required
def fight(id):
id = Fight.query.filter_by(id=id).first_or_404()
return render_template('fight.html', fight=Fight.query.filter_by(id=id).first())
to:
#app.route('/fight/<int:id>')
#login_required
def fight(id):
id = Fight.query.filter_by(id=id).first_or_404()
return render_template('fight.html', fight=Fight.query.filter_by(id=id.id).first())
because initially it was passing the argument 'fight_1' instead of just '1'. I hope nobody else has to spend this long trying to solve the same problem!
The use of id to hold a Fight confuses things. Then there's the double query when one would suffice.
Consider changing
id = Fight.query.filter_by(id=id).first_or_404()
return render_template('fight.html', fight=Fight.query.filter_by(id=id).first())
to
fight = Fight.query.filter_by(id=id).first_or_404()
return render_template('fight.html', fight=fight)
Related
I am sure I am probably being stupid but struggling to wrap my head around this one.
I have a flask website and I am setting up a checkout page for it so users can add their items to the cart etc. Everything was going great, I was able to add items to the cart, get a total etc (using sessions) however when I have tried to implement the ability for users to update the cart on the checkout page, when my form posts, the session data only survives the initial load. The print statement shows the data I am collecting is fine, and the session cookie is set initially, as everything updates, however the moment I then change page, it reverts to whatever it was before I made the update.
#views.route("/shopping-cart", methods=['GET','POST'])
def to_cart():
clear_cart = 'views.to_clear_cart'
if 'shopping' in session:
shopping_list = session['shopping']
sum_list = []
for quantity, price in shopping_list.values():
sum_list.append(quantity * price)
total = sum(sum_list)
if request.method == "POST":
new_quantity = int(request.form.get('quantity'))
product_id = request.form.get('issue')
unit_price = int(request.form.get('price'))
print(new_quantity, product_id, unit_price)
shopping_list[f'{product_id}'] = [new_quantity, unit_price]
return redirect(url_for('views.to_cart'))
return render_template("cart.html",
shopping_list=shopping_list,
total=total,
clear_cart=clear_cart,
)
else:
return render_template("cart.html",
clear_cart=clear_cart
)
I just do not really understand why it is not updating as from what I can tell, the code is running fine, and it does update, but then the session cookie just reverts itself to whatever it was before (using browser side cookies for this for testing).
Any help appreciated!!
After much confusion as everything seemed to be working absolutely fine after I rewrote this in about 5 different ways and printed half the app in the console, I finally found the answer and it is indeed me being an idiot.
It turns out if you modify a value in place rather than creating or deleting it does not automatically save the session state and you just need to state explicitly that it has been modified.
Turns out the answer was as simple as this line of code.
session.modified = True
I have been struggling with this simple query in django. I have checked a lot over internet. I tried using similar syntax - yet no luck.
In my application on html page I need to display some specific record. And for that i want to use parameterized select statement. But the query is not working..
I have checked id2 is getting correct value from previous html page..
And I know I can use APIs but for my databases classes I need to use raw queries in my application.
Can someone please help me here...
def details(request, id2):
temp = 'test3'
data = Posts.objects.raw('''select * from posts_posts where posts_posts.id = %s ''', id2)
context ={
'post' : data,
If you run that code you will see an error, since that is not the correct format for a call to raw. If you can't see the error output anywhere, then you have yet another problem for another post.
The correct format for raw is: .raw(sql, iterable-values), like this:
posts = Posts.objects.raw("select * ..", [id2, ]) # or use (id2,) for a tuple
<RawQuerySet: select * from ... where id = 5>
To get the actual list, since that just gives you a Query, you need to evaluate it somehow:
posts_list = list(posts)
first_post = posts[0]
Be careful, if you don't evaluate the QuerySet then it can be re-run a second time. Please convert it to a list() before doing further operations on it.
I'm very new to programming and especially to Django but can't work out how to use any previous answers to my advantage....
Apologies if my question is too vague but essentially, I have two different apps, let's call them app A and app B, with data on two different databases but apps contain information on the same individual item.
I want to edit this information on my 'edit details' page while keeping the apps as separate as possible (well AppB can know about functions in AppA but not vice-versa)...I guess what I really want is a signal which works like so:
A 'submit' view within AppA which is called when I submit changes to the data (using text boxes). The data for AppA is then saved..
And a signal then sent to AppB which ideally would update its data, before the HttpResponseRedirect is performed.
Unfortunately I can't really get this to work. My problem is that if I put 'request' into the arguments for save_details, I get errors like "save_details() takes exactly 3 arguments (2 given)"....does anyone know a clever way of getting something like this to work?
My submit function in AppA looks something like this...
def submit(self, request, id):
signal_received.send(sender=self, id=id)
q = get_object_or_404(AppA, pk=id)
q.blah = request.POST.get('wibble from the form')
...
return Http.....
in my AppB signals.py file, I have put.
signal_received = django.dispatch.Signal(providing_args=['id'])
def save_details(sender, uid, **kwargs):
p = AppB.objects.get(id=id)
p.wobble = request.POST.get('wobble from the form')
...
signal.received.connect(save_details)
Obviously the above doesn't mention request in its arguments which seems to be necessary but if I add that, I get problems with the number of arguments.
(I have imported all the right things at the top of each file I think...hence me leaving that off.)
Any point about the above would be appreciated....e.g. does "request" need to be the first argument? It didn't seem to like me using "self" before but I have tried to copy as much as possible the example at the bottom of the documentation (https://docs.djangoproject.com/en/dev/topics/signals/) but the extra functionality I need in the signal receiving function is flumoxing me.
Thanks in advance...
I'm trying to call a view directly from another (if this is at all possible). I have a view:
def product_add(request, order_id=None):
# Works. Handles a normal POST check and form submission and redirects
# to another page if the form is properly validated.
Then I have a 2nd view, that queries the DB for the product data and should call the first one.
def product_copy_from_history(request, order_id=None, product_id=None):
product = Product.objects.get(owner=request.user, pk=product_id)
# I need to somehow setup a form with the product data so that the first
# view thinks it gets a post request.
2nd_response = product_add(request, order_id)
return 2nd_response
Since the second one needs to add the product as the first view does it I was wondering if I could just call the first view from the second one.
What I'm aiming for is just passing through the request object to the second view and return the obtained response object in turn back to the client.
Any help greatly appreciated, critism as well if this is a bad way to do it. But then some pointers .. to avoid DRY-ing.
Thanx!
Gerard.
My god, what was I thinking. This would be the cleanest solution ofcourse:
def product_add_from_history(request, order_id=None, product_id=None):
""" Add existing product to current order
"""
order = get_object_or_404(Order, pk=order_id, owner=request.user)
product = Product.objects.get(owner=request.user, pk=product_id)
newproduct = Product(
owner=request.user,
order = order,
name = product.name,
amount = product.amount,
unit_price = product.unit_price,
)
newproduct.save()
return HttpResponseRedirect(reverse('order-detail', args=[order_id]) )
A view is a regular python method, you can of course call one from another giving you pass proper arguments and handle the result correctly (like 404...). Now if it is a good practice I don't know. I would myself to an utiliy method and call it from both views.
If you are fine with the overhead of calling your API through HTTP you can use urllib to post a request to your product_add request handler.
As far as I know this could add some troubles if you develop with the dev server that comes with django, as it only handles one request at a time and will block indefinitely (see trac, google groups).
Admin actions can act on the selected objects in the list page.
Is it possible to act on all the filtered objects?
For example if the admin search for Product names that start with "T-shirt" which results with 400 products and want to increase the price of all of them by 10%.
If the admin can only modify a single page of result at a time it will take a lot of effort.
Thanks
The custom actions are supposed to be used on a group of selected objects, so I don't think there is a standard way of doing what you want.
But I think I have a hack that might work for you... (meaning: use at your own risk and it is untested)
In your action function the request.GET will contain the q parameter used in the admin search. So if you type "T-Shirt" in the search, you should see request.GET look something like:
<QueryDict: {u'q': [u'T-Shirt']}>
You could completely disregard the querystring parameter that your custom action function receives and build your own queryset based on that request.GET's q parameter. Something like:
def increase_price_10_percent(modeladmin, request, queryset):
if request.GET['q'] is None:
# Add some error handling
queryset=Product.objects.filter(name__contains=request.GET['q'])
# Your code to increase price in 10%
increase_price_10_percent.short_description = "Increases price 10% for all products in the search result"
I would make sure to forbid any requests where q is empty. And where you read name__contains you should be mimicking whatever filter you created for the admin of your product object (so, if the search is only looking at the name field, name__contains might suffice; if it looks at the name and description, you would have a more complex filter here in the action function too).
I would also, maybe, add an intermediate page stating what models will be affected and have the user click on "I really know what I'm doing" confirmation button. Look at the code for django.contrib.admin.actions for an example of how to list what objects are being deleted. It should point you in the right direction.
NOTE: the users would still have to select something in the admin page, otherwise the action function would never get called.
This is a more generic solution, is not fully tested(and its pretty naive), so it might break with strange filters. For me works with date filters, foreign key filters, boolean filters.
def publish(modeladmin,request,queryset):
kwargs = {}
for filter,arg in request.GET.items():
kwargs.update({filter:arg})
queryset = queryset.filter(**kwargs)
queryset.update(published=True)