Ok, this might take a bit of explanation.
I have a class called PurchaceOrder, which has a form with 18 fields. A lot of the time, there will be several PurchaceOrders with the first 12 fields being the same. To facilitate this (and remove the chance of a user making an error when trying to make the 12 fields the same every time) I have a form that allows the user to add more than one PurchaceOrder with the first 12 Fields being carried over from one entry to the next. This is all fine and good, and is working very well.
However; I need a splash page after the user is done adding all of his/her PurchaceOrders, that shows all the entries that were just made. This means I need to track the new entries that are being created, but I can't think of a way to do this. For now I'm just filtering the categories, so that the PurchaceOrders with the first 12 fields being the same as the ones just entered are displayed, but this obviously won't really work (there could be a previous entry that has those 12 fields that are the same). What I'd really like to have is a list of Primary Keys of the entries that were just created. I could then pass this information onto the view that's responsible for the confirmation landing page.
In my current view I have the following:
if form.is_valid():
entry=form.save()
My thinking was that I could then do something like:
pks = [pks, entry.id]
I don't know where I would instantiate the list. If I did it in the view, it would be whipped out every time the page was reloaded.
I'd appreciate any help.
My first thought would be to have a separate class/method/function that keeps track of the PurchaceOrder's in each form. The ID could be tied to the result through a database or array/linked list that is auto-incremented when a new PurchaceOrder is created.
As far as instantiating the list, have it instantiated when the class is first called, or have it as a separate class. After writing that, a separate class makes more sense, which is probably why I posted it that way originally.
After leaving this alone for a long time, I've finally come up with a suitable solution. What I've done is created a url conf that has a regex of (?P<match>/+)/in it. That rexeg will be used to contain an arbitrary number of primary keys separated by /. I use this to store all of the primary keys of the PurchaseOrders that have been created (that is, when I create PurchaseOrder number 15, it redirects me to /new/15, then when I create number 16, it directs me to /new/15/16/, and so on. Then when I'm ready to confirm, I'm sent to /confirm/15/16/ and I can easily access the pk's of the entries I've just created by calling pks=match.split('/'). I can then simply iterate through pks and do something for each object. I think it's an elegant solution, as long as you don't mind your user seeing the primary keys in the url.
Related
I'm building a Django web application, part of it involves an online ordering system for food. I want to make a "receipt" object to save transactions.
My concern, however, is this - let's say I have an object Receipt that relates to Orders which relate to Items, if the items get edited or change over time, it will make the receipts look different down the line. Is there a way to save these at the moment of a transaction?
I am implementing a "soft deletion" to my models to avoid deletion issues however I don't think this would protect against edits.
The only way I can think of to deal with is to 'materialize' the Receipt. In other words when a receipt is generated use the Order and Items information current at the time and then write the actual values, not the Order/Items id to a receipt table. So for a Items item write out the attributes(description, price, qty.etc) you are interested in recording to the table, instead of just an Items.id that points to a possibly changed value in future.
My application creates several rows of data per customer per day. Each row is modified as necessary using a form. Several modifications to a row may take place daily. At the end of the day the customer will "commit" the changes, at which point no further changes will be allowed. In each row I have a 'stage' field, stage=1 allows edits, stage=2 is committed, no further changes allows.
How can I update the stage value to 2 on commit?
In my model I have:
#property
def commit_stage(self):
self.stage = 2
self.save()
Is this the correct way to do this? And if so, how to I attach this function to a "commit" button.
I suspect you are confused about what properties do. You should absolutely not attach this sort of functionality to a property. It would be extremely surprising behaviour for something which is supposed to retrieve a value from an instance to instead modify it and save it to the db.
You can of course put this in a standard model method. But it's so trivial there is no point in doing so.
In terms of "attaching it to a button", nothing in Django can be called from the front-end without a URL and a view. You need a view that accepts the ID of the model instance from a POST request, gets the instance and modifies its stage value, then saves it. There is nothing different from the form views you already use.
So I have a list of unique pupils (pupil is the primary_key in an LDAP database, each with an associated teacher, which can be the same for several pupils.
There is a box in an edit form for each teacher's pupils, where a user can add/remove an pupil, and then the database is updated according using the below function. My current function is as follows. (teacher is the teacher associated with the edit page form, and updated_list is a list of the pupils' names what has been submitted and passed to this function)
def update_pupils(teacher, updated_list):
old_pupils = Pupil.objects.filter(teacher=teacher)
for pupils in old_pupils:
if pupil.name not in updated_list:
pupil.delete()
else:
updated_list.remove(pupil.name)
for pupil in updated_list:
if not Pupil.objects.filter(name=name):
new_pupil = pupil(name=name, teacher=teacher)
new_pupil.save()
As you can see the function basically finds what was the old pupil list for the teacher, looks at those and if an instance is not in our new updated_list, deletes it from the database. We then remove those deleted from the updated_list (or at least their names)...meaning the ones left are the newly created ones, which we then iterate over and save.
Now ideally, I would like to access the database as infrequently as possible if that makes sense. So can I do any of the following?
In the initial iteration, can I simply mark those pupils up for deletion and potentially do the deleting and saving together, at a later date? I know I can bulk delete items but can I somehow mark those which I want to delete, without having to access the database which I know can be expensive if the number of deletions is going to be high...and then delete a lot at once?
In the second iteration, is it possible to create the various instances and then save them all in one go? Again, I see in Django 1.4 that you can use bulk_create but then how do you save these? Plus, I'm actually using Django 1.3 :(...
I am kinda assuming that the above steps would actually help with the performance of the function?...But please let me know if that's not the case.
I have of course been reading this https://docs.djangoproject.com/en/1.3/ref/models/querysets/ So I have a list of unique items, each with an associated email address, which can be the same for several items.
First, in this line
if not Pupil.objects.filter(name=name):
It looks like the name variable is undefined no ?
Then here is a shortcut for your code I think:
def update_pupils(teacher, updated_list):
# Step 1 : delete
Pupil.objects.filter(teacher=teacher).exclude(name__in=updated_list).delete() # delete all the not updated objects for this teacher
# Step 2 : update
# either
for name in updated_list:
Pupil.objects.update_or_create(name=name, defaults={teacher:teacher}) # for updated objects, if an object of this name exists, update its teacher, else create a new object with the name from updated_list and the input teacher
# or (but I'm not sure this one will work)
Pupil.objects.update_or_create(name__in=updated_list, defaults={teacher:teacher})
Another solution, if your Pupil object only has those 2 attributes and isn't referenced by a foreign key in another relation, is to delete all the "Pupil" instances of this teacher, and then use a bulk_create.. It allows only 2 access to the DB, but it's ugly
EDIT: in first loop, pupil also is undefined
I want to be able to create as many records as a user wants for a database table in a single form.
For example, there will be some inputs for the data required for a record and at the end of the line a "+" button that would make a new line of inputs appear. There should be no limit to the number of lines and when the user clicks on the single submit button, all of the records would be inserted.
Thing is : I don't know how to make a new line appear dynamically, I suppose I have to use jquery for that but I'm kind of a newbie :)
And I don't know how I can iterate through all the lines dynamically added.
If someone can point to an example or something, it'd save me a lot of hair pulling !
EDIT :
By following this blog post I managed to do that. I have one last problem which is : when I try to insert several records at one time, it keeps the last one fine, but the previous ones are considered empty. It tells me that the fields are required, I fill them up and click on save and only then it saves them allright.
Maybe I'll ask a new question for this!
Start here: https://docs.djangoproject.com/en/1.3/topics/forms/modelforms/#model-formsets
I suppose I have to use jquery for that
That can also work.
And I don't know how I can iterate through all the lines dynamically added.
You'll get all the fields of the form (all of them) in your request.POST object. If you use a formset, it will largely be handled by the form's clean() and save() methods.
I'm trying to make a Django order system that requires 2 forms. The first form, lets users choose some some quantities and basic contact info some. Then, using the quantities of each item they ordered I generate a 2nd form which allows them to choose some options for each item. This system is specifically for event tickets. Here are the 2 stages:
1) Get the order info such as name, address, phone of the person placing the order. Also find out how many people are coming to each of the possible events.
2) Based on the number of people per event, get their name and e-mail address.
I already have both forms created. I am just getting tripped up in the views. When they submit form 1, I need to take that info and save some of it and then send them to form 2. At form 2, they will fill out the rest of the info and finish processing.
How would you set up the views in such as case? I essentially nee-d to call on view form another and pass data between. I tried using kwargs, but I have trouble processing the second form.
Without seeing your models, it's hard to give an exact solution, but one approach is to have two separate views, one for each form.
Once you've processed the first form, you're most likely going to have an instance of some object that you created from the first form. It sounds like you just need to pass the id of that object to your next view where you could then get that object and do whatever association you need.
Also, it sounds like you might need to be collecting data from several instances of a form...
(2) Based on the number of people per event, get their name and e-mail
address.)
You'll want to use a formset for that.