My class communication design problem.

[Yarick Antonov]

I have serious OOP design problem, and i don't know the way to solve it.

Here are two of my views:

def exercise(request):
    if request.method == 'GET':
        request.session["exercise_start"] = time()
        form = ExerciseForm(language = request.session["language"], dictionary = request.session["dictionary"])

    elif request.method == 'POST':
        form = ExerciseForm(request.POST, language = request.session["language"], dictionary = request.session["dictionary"])

        if form.is_valid():
            ExerciseTime = time() - request.session["exercise_start"]
            ExerciseText = form.cleaned_data["exercise_field"]

            if request.user.is_authenticated():
                exercise = Exercise(player = request.user)
                exercise.time = ExerciseTime
                exercise.save()

            request.session["exercise_text"] = ExerciseText
            request.session["exercise_time"] = ExerciseTime
            return redirect('game_result')
    return render(request, "game/exercise.html", {'form': form})

def result(request):
    exercise_result = {"exercise_text": request.session["exercise_text"], "exercise_time": request.session["exercise_time"]}
    return render(request, "game/result.html", exercise_result)

And here is my "exercise form" which obviously used by "exercise view":

class ExerciseForm(forms.Form):
    def __init__(self, *args, **kwargs):
        self.language = kwargs.pop('language', None)
        self.dictionary = kwargs.pop('dictionary', None)
        self.exercise_text = self.getRandomText(lng=self.language, dct=self.dictionary)
        self.SetExText()
        super(ExerciseForm, self).__init__(*args, **kwargs)

    def SetExText(self):
        self.exercise_text = self.getRandomText(self.language, self.dictionary)
        self.exercise_field.exercise_text = self.exercise_text

    def getRandomText(self, lng, dct):
        count = ExerciseText.objects.filter(dictionary__dictionary_name = dct).count()
        if count:
            rand_id = sample(range(1, count), 1)
            return ExerciseText.objects.get(id__in=rand_id).text
        else:
            return "lol"

    exercise_field = ExerciseField(exercise_text = exercise_text, widget = forms.TextInput(attrs = {'autocomplete': 'off', 'autofocus': 'autofocus'}))

My field, used in form above:

class ExerciseField(forms.CharField):
    def __init__(self, exercise_text, *args, **kwargs):
        self.exercise_text = exercise_text
        super(ExerciseField, self).__init__(*args, **kwargs)

    def validate(self, value):
        if value != self.exercise_text:
            raise ValidationError("Texts don't match")

And finally, simple template:

{% extends "base.html" %}

{% block content %}
<form action="game_result" method="post">
    {% csrf_token %}
    {{ form.exercise_text }}<br/>
    {{ form.as_p }}
</form>
{% endblock content %}

What i try to do:
I try to bargain two arguments which come from "create view" which not represent here in sake of space saving, and these two arguments are "language", and "dictionary".
I use them to get a record from db table, to get random text.

And here I need your help, because i can't dynamically create variable "exercise_text", because i need it in Class instance.
Meaning - it need to be predefined before I'll use my "exercise_field.

And also i can't put exercise_field inside of "__init__", because it will not be accessible in template.

In short:
I need to get random record from db, and i need to put this record in my field. How to do that? Dynamically.

[Kyle Connors]

I believe what you're looking for is an initial value. In __init__ the following would achieve this:

self.fields['exercise_field'].initial = self.getRandomText(self.language, self.dictionary)

[Collin Anderson]

I'd recommend not using a custom field for this. Instead, you can do something like:

class ExerciseForm(forms.Form):
        exercise_field = forms.CharField(widget=forms.TextInput(attrs={'autocomplete': 'off', 'autofocus': 'autofocus'}))

        def __init__(self, *args, **kwargs):
            self.language = kwargs.pop('language', None)
            self.dictionary = kwargs.pop('dictionary', None)

            self.exercise_text = self.getRandomText(self.language, self.dictionary)
            super(ExerciseForm, self).__init__(*args, **kwargs)

        def clean_exercise_field(self):
            if self.cleaned_data['exercise_field'] != self.exercise_text:
                raise forms.ValidationError("Texts don't match")
            return self.cleaned_data['exercise_field']

https://docs.djangoproject.com/en/dev/ref/forms/validation/#cleaning-a-specific-field-attribute

[Yarick Antonov]

Your solution works!!! Thanks a lot!!!