Wizard input - DB View - Dynamic where clause - python-2.7

I was trying to pass where condition values onto a database view.
View was created in init method of class defined.
Input to where clause was taken from a popped up wizard.
Issue is that the wizard form values are inserted into model bound database table.
This is happening on all submits.
Currently I am reading the latest record from table on wizard input.
And the view definition is modified to generate result set based on latest input record from wizard table.
select v.col1, v.expre2
from view_name v,
( select fld1, fld2 from wizrd_tbl_1 order by id desc limit 1 ) as w
where
v.colM between w.fld1 and w.fld2
Currently I am following the above sequence of steps and results are fetched.
But I think, this would fail if at least two users are using the same wizard concurrently.
How can I change my approach, so that
1. Wizard input is not sent to database table,
2. The inputs are sent to a where clause dynamically and the result set is bound to a List View
As a summary, I was trying to:
Creates a database view joining multiple table.
Take user input ( and saves in db table, which is not expected and
not required ).
Pass the user input to db view's where clause. ( Any alternative to wizard ? )
Bind the result set to List View

It is definitely a bad idea to morph a database view based on user input, when that view is likely to be accessed by multiple users.
The 'correct' way to do this would be to have a static database view which contains all possible records from the joined tables, and then filter that data for individual users by generating a "domain" and redirecting the user to a tree view with that domain applied.
You can redirect the user by creating a <button type="object"> which calls a function such as the below:
def action_get_results(self, cr, uid, ids, context={}):
# Redirect user to results
my_domain = ['&', ('col1','=','testval'), ('col2','>',33)]
return {
'type': 'ir.actions.act_window',
'name': 'Search Results',
'view_mode': 'tree',
'res_model': 'your.osv_memory.model.name',
'target': 'new', # or 'current'
'context': context,
'domain': my_domain,
}

Related

Django function execution

In views, I have a function defined which is executed when the user submits the form online. After the form submission there are some database transactions that I perform and then based on the existing data in the database API's are triggered:
triggerapi():
execute API to send Email to the user and the administrator about
the submitted form
def databasetransactions():
check the data in the submitted form with the data in DB
if the last data submitted by the user is before 10 mins or more:
triggerapi()
def formsubmitted(request):
save the user input in variables
Databasetransactions()
save the data from the submitted form in the DB
In the above case, the user clicks on submit button 2 times in less than 5 milliseond duration. So 2 parallel data starts to process and both trigger Email which is not the desired behavior.
Is there a way to avoid this ? So that for a user session, the application should only accept the data once all the older data processing is completed ?
Since we are talking in pseudo-code, one way could be to use a singleton pattern for triggerapi() and return Not Allowed in case it is already istantiated.
There are multiple ways to solve this issue.
One of them would be to create a new session variable
request.session['activetransaction'] = True
This would however require you to pass request, unless it is already passed and we got a changed code portion. You can also add an instance/ class flag for it in the same way and check with it.
Another way, which might work if you need those submissions handled after the previous one, you can always add a while request.session['activetransaction']: and do the handling afterwards.
def formsubmitted(request):
if 'activetransaction' not in request.session or not request.session['activetransaction']:
request.session['activetransaction'] = True
# save the user input in variables
Databasetransactions()
# save the data from the submitted form in the DB
request.session['activetransaction'] = False
...

Allowing users to only view data related to them in Apache Superset

I have some information related to different vendors in my database and I want to allow each registered vendor (representative person) to view slices/dashboards which contains only data related to them.
One possible solution could be to create separate views for each vendor as well as separate roles for each vendor. But it feels like a bad idea if you have 100+ vendors (as is my case); and it's not a flexible or scalable solution.
Is there some way to automatically filter a given view for each user? For example, we have a "general profit by product" bar chart, and user X can see only products of vendor X
What you're looking for is multi-tenancy support, and this is not currently supported out-of-the-box in Superset.
There is however an open PR for one possible solution: https://github.com/apache/incubator-superset/pull/3729
One option could be to re-use and/or adapt that code for your use-case.
Another option might be to look into JINJA_CONTEXT_ADDONS [https://github.com/apache/incubator-superset/blob/master/docs/installation.rst#sql-lab] and see whether you might be able to pass additional context to your query (e.g. your vendor_id) and restrict the scope of your query using that parameter.
Superset config has the below two configurations(DB_CONNECTION_MUTATOR, SQL_QUERY_MUTATOR), which can allow for multi-tenancy to an extent.
A callable that allows altering the database conneciton URL and params
on the fly, at runtime. This allows for things like impersonation or
arbitrary logic. For instance you can wire different users to
use different connection parameters, or pass their email address as the
username. The function receives the connection uri object, connection
params, the username, and returns the mutated uri and params objects.
Example:
def DB_CONNECTION_MUTATOR(uri, params, username, security_manager, source):
user = security_manager.find_user(username=username)
if user and user.email:
uri.username = user.email
return uri, params
Note that the returned uri and params are passed directly to sqlalchemy's
as such create_engine(url, **params)
DB_CONNECTION_MUTATOR = None
A function that intercepts the SQL to be executed and can alter it.
The use case is can be around adding some sort of comment header
with information such as the username and worker node information
def SQL_QUERY_MUTATOR(sql, username, security_manager):
dttm = datetime.now().isoformat()
return f"-- [SQL LAB] {username} {dttm}\n{sql}"
SQL_QUERY_MUTATOR = None
One easy way of solving this problem is by using pre-defined JINJA parameters.
Two parameters that can be used are '{{current_username() }}' and {{current_user_id() }}
First you need to ensure that you can use JINJA templates -
In superset_config.py add the following
FEATURE_FLAGS = {
"ENABLE_TEMPLATE_PROCESSING": True,
}
Restart
Now if you go to the SQL LAB and type the following -
SELECT '{{ current_username() }}',{{ current_user_id() }};
You should get an output
?column?
?column?__1
PayalC
5
Now all you have to do is append one of the two following sql snippet in all your queries.
select ........ from ...... where ...... vendorid={{ current_user_id() }}
select ........ from ...... where ...... vendorname='{{ current_username() }}'
vendorid={{ current_user_id() }} and/or
vendorname='{{ current_username() }}' will restrict the user to view only her data.
You could also make it more flexible by creating a table which has a mapping of user to vendorid. That table can be your added to all the queries and you could map multiple vendors to a single user or even all vendors to a single user for a super admin.

Django - Create new object in Form, update select box and save it

I think what I'm trying to achieve is not hard, but I have no clue how to do it hehehehe !
Basically what I need is the feature that we have in Django Admin, when you are creating a new object, if you have a Foreign Key, you can add new data (opening a pop-up), save it and then the select box updates automatically.
What I have is this form:
I know that would be easy to do it with some Javascript, but my point is, Django has some rules, and as far I know, I can't add new data to a form already created, right? Otherwise Django won't validate this form. How could I achieve this?
PS: "Local" is the select box where I want to add new data. The user should be able to create a new Local on this page, instead of going to another page to do it. Thanks :)
Here your question:
I can't add new data to a form already created, right? Otherwise Django won't validate this form. How could I achieve this?
Then the answer:
you are right, django will check values match form value rules. But:
realize that your main form is invoked for twice: on GET and on POST. Between both form executions you make changes on database values trhough your new form. That means that in second main form invocation the value added to database is available:
field1 = forms.ModelChoiceField(queryset= ***1*** )
***1***: on second invocation new value is already available on field1.
Then, you don't should to be afraid about this subject, the new value will be available on form on your main form POST request.
Nothing wrong with updating the value using javascript as long the key in your new combo box has the right key in the database then it should be ok.
Call this function after you saved the last entry.
function refreshLocal(){
$.get(window.location.href, '', function(html){
// change the id to the local combox's id
var serverLocalDropBox = $(html).find('#id_local');
if (serverLocalDropBox.length){
$('#id_local').replaceWith(serverLocalDropBox);
}
})
}
If you don't want to use javascript solution, you can post the form with refresh flag and on the server side if you see that flag just don't validate and return the form as is. Since you have a new entry in the foreignkey it will automatically update the queryset to include the new entry.
function serverRefreshLocal(){
var $form = $('#your_form_id');
$form.append('<input type="hidden" name="refresh" value="true" />');
// you can use ajax submit and ajax refresh here if you don't want to leave the page
$form.submit();
}
// Server Side
def your_form_post_view(request):
if request.POST.get('refresh', 'false') == 'true':
# initial is the trick to save user input
your_form = YourForm(initial=request.POST)
context = {
'form': your_form,
}
return render(request, 'your_template.html', context)
# your view code goes here

Django - how to pass more than one primary key to the view

I need to write a view to delete multiple objects in one go.
I have modified the HTML template, put checkboxes to select which objects (users) to delete and a button to delete them, but of course you need a view to perform the task.
When you have one item to select at a time, you pass its primary key to the view through the url, how can I extend this to pass more than one primary key?
You would absolutely not be doing this via the URL. If you have a set of checkboxes, then you have a form; since the form is doing destructive operations it will be submitted via POST: therefore your set of IDs is in request.POST.
What you can do is to send the data in a JSON format, which can easily be decoded by Django
On the frontend, you'd have a JavaScript for a button like so,
function delete_object(pks) {
var args = {type: "POST", url: "/delete/", data: {'pks': pks}};
$.ajax(args);
return false;
}
this function would take selected the primary keys from (which is passed in as pks) and POST it to the Django url ^delete/$. A Django view function can then handle the incoming data like so,
def delete(request):
object_pks = request.POST['pks']
Docs.objects.filter(pk__in=object_pks).delete()

How to find user group and use of caching in django?

I am new to django/python and working my way through my webapp. I need assistance in solving one of my problems.
In my app, I am planning to assign each user (from auth_user) to one of the group ( from auth_group). Each group can have multiple users. I have entry in auth_group, auth_user and auth_user_groups. Here is my question:
At time of login I want to check that logging user belongs to which group?
I want to keep that group info in session/cache so all pages I can show information about that group only.
If you have any sample code will be great.
Giving support to the very well #trinchet's answer with an example of context_processor code.
Puts inside your webapp a new file called context_processors.py and writes this lines on it:
def user_groups(request):
"""
Add `groups` var to the context with all the
groups the logged in user has, so you can access
in your templates to this var as: {{ groups }}
"""
groups = None
if request.user.is_authenticated():
groups = user.groups
return {'groups': groups}
Finally on your settings.py add 'webbapp.context_processors.user_groups'to TEMPLATE_CONTEXT_PROCESSOR:
TEMPLATE_CONTEXT_PROCESSORS = (
'webbapp.context_processors.user_groups',
)
1) Be user an instance of auth.models.User, you can get all groups the user belong to, through user.groups. If you want to ask at time of login then you should do this in your login view.
2) You can use session or cache approaches to deal with, this is irrelevant, but once you have the group you need to render the pages having this value, i mean, you need to provide the group to the template rendering, to do this I suggest to you using a custom context processor.