I could also use a TextField, but that's not ideal from UX point of view. I would like to know if there's a field that allows the user to enter multiple custom strings (not from a pre-defined list of options), one at a time, where, to enter a string, one needs to press enter, these values are then passed as a list of strings (or other types) to the model, which defines an ArrayField.
I've searched for some time, but I couldn't find it. I'm not really an expert in Django, but I suppose such a field must exist.
If not, I suppose I could create a custom form field that does that.
Here's what I mean.
In the example, 1 was written, then the user pressed ENTER, and the option was added; then the same thing happened to add 2; the important thing to note is that 1 and 2 do not come from a predefined set of values, but were custom strings entered by the user, which can also be removed after having been entered.
If I've got your question right, you want a ArrayField for your form. Take a look at SplitArrayField:
from django.contrib.postgres.forms import SplitArrayField
class SthForm(forms.Form):
arr_field = SplitArrayField(forms.CharField(max_length=100))
Related
I have a database filled with values for first_name. I also made a form, which calls for an input of first_name. How can i give the user suggestions as they type of names that are already in the database?
Also, if i have someone entering 2 in one integerfield, and a 3 in another integerfield, how can i autocompute the product and show it in real-time?
The package https://github.com/yourlabs/django-autocomplete-light seems to be what you're looking for.
It allows the end user to type some characters, after which it will be autocompleted/suggested from what's already in the DB.
For autocomputing the two intergerfields, I'd go for client-side (Javascript).
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.
I asked a question similar to this previously (How to use RecId as a foreign key in a form) but would like to explore it a bit further in a more complex scenario.
Replacement keys work great when you have indexes set up and allow duplicates set to no, but they don't seem to work at all with multiple-field indexes or when allow duplicates is set to yes.
Is there way, programmatically, to replace a foreign key in a grid with a translated value without using replacement keys? I tried writing a display method to override the field, but some odd behavior resulted--fields moving around in the grid, and the display method being unaware of which row to use, thus all values in the entire column were the same.
Table A: Bob:1, Sally:1, Sue:3
Table B: 1:Apples, 2:Apples, 3:Oranges
The "people" are tied to their favorite "foods" by the food RecId, refererenced in the People table. Assume there is additional data in other columns that make these records unique, so consolidating "1:Apples" and "2:Apples" is not possible.
It seems there should be a way to write a display method to overwrite a field value in a grid. Any suggestions? Sample code?
Thanks
Firstly, surrogate FK replacement does (or at least should) work with composite keys (e.g., {First Name, Last Name}).
Secondly, you state that there is "additonal data in other columns" that make these records unique...Then why aren't these columns being combined with the food's name to form an alternate key? The data model seems incorrect (or at least some metadata isn't being made consistent with the conditions you've stated)
Thirdly, any Field Group can be chosen as the ReplacementFieldGroup on a Reference Group control. That alone will allow you to do basically whatever you want. That said, I would strongly encourage you to use an alternate key as your replacement field group whenever possible due to the semantics of surrogate FK replacement.
Flow:
1) User types a value(s) into reference group.
2) User's tabs out.
3) User's typed value(s) are used to look up a record in the related table.
4a) If the user's typed in value(s) are uniquely mapped to a record that record is chosen, else,
4b) If the user's typed in values are not unique a lookup is presented to allow the user to pick which record they "meant". Note that the lookup must therefore present a collection of uniquely identifiable records so that the user knows which record to pick (if the records all look the same in the lookup then they'll have no idea what in the hell they should pick.)
5) Upon successful resolution of the typed values, the record is set back on the source form.
Given this flow, it is obvious that steps 3-5 will be broken if there is no unique index (key) on the table. (How is the user supposed to specify a unique reference to the record if the record has no means of being uniquely identified (assuming you don't want to display RecId to the user)???)
In the exceptional case that you decide that you still want to use a non-unique index as your replacement field group you must implement resolveReference and lookupReference to provide the user a unique resolution/lookup experience (to handle steps 3-5 in the above flow). Note: The common use case for this is wanting to effectively eliminate non-selective fields from being displayed in Reference Group and instead letting some outer context or mode implicitly set that value. E.g., if the alternate key was {Size, Color}, one could potentially make "Color" a global form context--perhaps by having the user pick a color at the top of the form--and only have the user enter Size into Reference Group...The Color could then be implicitly added back via the resolveReference and lookupReference overrides.
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 have a model which represents the user's display preferences. Just about all of these preferences are boolean values. Instead of having 50 boolean columns, is there a better way to go about this? In the future when I want to add a new item, I don't want to have to add a new column in my database.
If you have that many booleans and are anticipating adding more, you should not be using columns, but entries.
Then when you need to look up "User wants emails", just search for UserPrefs.objects.get(User=user, Preference=Preferences.objects.get(name="wants email")).
User_Table:
User
username
etc
Preferences_Table:
name
description
etc
UserPreferences_Table:
User (FK_User)
Preference (FK_Preferences)
Setting (Boolean)
Depending on your setup, you may be able to omit the Setting field in the UserPreferences table and simply use the existence of an entry for that User/Preference as a True and the lack of one as a False.
You could also use a bitmap. You only need single char field in you database. Somewhere in your app you store a list of preferences, pref1, pref2, pref3 ... and in the bitmap filed you store a sequence of 1's and 0's that correspond to the preferences.
For example 101 means pref1=yes, pref2=no, and pref3=yes and 011 means pref1=no, pref2=yes, and pref3=yes.
You could make this reusable by creating a new model field type for bitmaps.
" In the future when I want to add a new item, I don't want to have to add a new column in my database."
In this case, you'll want to add a row.
You have a table with the domain of possible setting Names. 50 rows.
You have a table of actual settings. User, Setting Name, Setting Value.