Hiding ModelMultipleChoiceField on template for custom input - django

I want the user to select a number of elements belonging to a certain model. I don't want to use the default 'ctrl+click' input of django forms, but create a table of checkboxes myself.
For that reason I hide the ModelMultipleChoiceField by defining the widget:
field = forms.ModelMultipleChoiceField(..., widget=forms.MultipleHiddenInput())
Then I add the form element into the template as follows:
<form method="POST" class="locklist-form" id="locklist-form">{% csrf_token %}
{{ form.field }}
</form>
At this step, I expect the select-option elements to be added to HTML page (as hidden), so that I can reach to element options and modify them with javascript. However, it doesn't add anything to the HTML page.
I use this approach with other type of form fieds. For a TextField HTML page have a hidden element as shown:
Why doesn't it work with ModelMultipleChoiceField? How can I modify the choices of this field with Javascript?
Edit:
MultipleHiddenInput renders only if with initial data is a similar question. But applying it doesn't lead to the expected solution. In this question, it is expected to render the following as hidden:
But following the MultipleHiddenInput renders only if with initial data, when I modify the form constructor as:
form = MyForm(initial={'field':MyModel.objects.all()})
Rendered element is as follows:
It maybe useful, but not exactly the expected one. I need to mark a few options as selected, among a list of objects.

I have done it using Javascript, instead of depending on Django's capabilities. I add the form with ModelMultipleChoiceField directly to the template (not hidden). Then I run a Javascript script, when the page is loaded:
var field = document.getElementById('id_field');
selecter.setAttribute('class', 'hidden');
CSS definition of hidden class is as follows:
.hidden{
display: none;
}
This gets me to the desired situation. ModelMultipleChoiceField is rendered hidden as follows:
At this point, I can modify certain items through Javascript:
document.getElementById('id_field').options[index].selected = boolValue;

Related

Set a variable through a drop down list in django

def scan(request):
scan = Stock.objects.all()
hammer = Stock.objects.filter(Hammer=100)
belthold = Stock.objects.filter(Belthold=100)
context = {'All':scan, 'Belthold':belthold, 'Hammer':hammer
}
return render(request, 'scanner/scan.html', context)
This is my views.py file. I want to add a dropdown list to my html page containing the context dictionary which changes the query filters according.
This is my current html page:
{% for i in Hammer %}
<tr>
<td>{{i.script}}</td>
<td>{{i.open}}</td>
<td>{{i.high}}</td>
<td>{{i.low}}</td>
<td>{{i.close}}</td>
<td>{{i.Volume}}</td>
<td>{{i.Change}}</td>
</tr>
{% endfor %}
The 'Hammer' need to be replaced by whatever selection is made from the dropdown list.
THANKS!!
You cannot dynamically change Hammer in a template for loop. You can use the approach below or change the approach as to how you want everything displayed.
You have to use Javascript for that. You first need to give id's to all the tags you have in the for loop.
<td id="{{i.script}}_myid"> ...
Then with Javascript access the change in the dropdown menu's value and then update the respective td's accordingly:
document.getElementbyId('dropdown').addEventListener('change', function(e) {
// Change td's here: document.getElementbyId(..._myid).innerHTML = "" })
To pass Hammer in your JS you can either do an inline script (which many dont recommend) or a separate JS file added as a script tag below. You can use serializers to pass on the objects from Python to JS.

How can one create a custom "as_table()" method for forms?

I have a relatively complicated form that's used in multiple places on my website (in fact, it's a form from which many other form classes inherit). In the templates, the inherited part of this form is always formatted identically—but that formatting is somehwat involved; each field is rendered and positioned manually in the template.
This means that every template which displays this form has a lot of identical HTML markup that renders the form appropriately.
I would like to create a custom output that can be called, similar to the as_table() methods. I'm aware that one can override the normal_row, error_row, etc. attributes—but the formatting of this form goes beyond that (for example, three of the form's five fields should be printed side-by-side, with a combined title). All of the tutorials/answered-questions I've seen either refer to overriding the above-mentioned attributes, or give instructions on how to manually render forms.
Originally, I was thinking something like this:
Class StrangeForm(form.Forms):
....
def as_table_custom():
html_string = "\
<tr><td>Title 1:</td><td>self.fields['field1']</td><tr>\
<tr><td>Title 2:</td><td>self.fields['field2']</td><tr>\
<tr><td>Titles 3, 4, 5:</td><td>self.fields['field3']\
</td><td>self.fields['field4']</td><td>self.fields['field5']</td></tr>\
"
return html_string
But, after reading through the _html_output() and as_table() methods of Django's forms.py file, it doesn't look like it'll be that easy. If I write this from scratch, have to somehow account for errors, help text, etc. I think.
Is there an easy way to override something such that the form's HTML output can be defined like above? Or do I have to re-write things from scratch. If the latter, how can I account for all of the things I need to account for?
I wouldn't take this approach. You're better off creating the form in an HTML template that you include in the various templates where you have a form you want to display that way.
So create a my_strange_form.html template where you assume a 'form' object is passed in the context with the right number of fields. In that template just create the HTML, using things like {{ field.label_tag }} and {{ field }}. You can loop through the fields with a {% for field in form %} and check the counter of your loop with {{ forloop.counter }}. I foresee a lot of {% if forloop.counter... %} statements to generate the combined row, and it will look ugly, but you'll only have to look at it once :-)
Then in your main templates {% include 'my_strange_form.html' with form=form %}.

Django: Generate form from dictionary

I'm currently working on a django-app where users have the option to select synonyms for a select number of words. These words are then replaced all over the website by these synonyms
these synonymes are defined as a separate model:
class TransportSynonyms(models.Model):
user= models.ForeignKey(user)
key = models.CharField(max_length=255)
value = models.CharField(max_length=255)
This process is done in part with template tags, and as such the number of words that can be 'synonymed' is limited. For example, the following words can be replaced by synonymes:
'train', 'plane'.
And appear like so in the html template:
{% get_trans "train" %}
{% get_trans "plane" %}
I now want to give user the ability to define synonymes for themselves, without the admin view. I created a few pages using a ListView as an overview (so the users could see which words they can change) with individual buttons that led to EditViews.
However, I'm since user have no synonyms linked to them by default, the ListView appears empty. I could solve that by passing a list from the view, but that list wont have the required '.id' values and would be worthless for linking to the EditViews.
My listview currently looks like the following table:
Original | Synonym
---------------------------
train | train (button to editview)
plane | aircraft (button to editview)
The buttons require an ID value
href="{% url 'synonym_edit' pk=synonym.id %}"
I have to find a way to fill the ListView with the 'synonymable' words and provide links to a DetailView (for synonyms might not yet exist).
I thought about dropping the ListView all together and instead pass a dictionary to a form. By default both the key and the value will be the same word
({'train' : 'train', 'plane' : 'plane'})
and a form would then be generated form this dictionary, allowing users to change the value by having the dictionary value be shown as a text input.
Its a bit more limited (and more cumbersome) than my original plan, but I think this might work. Problem is that I've only really worked with modelforms before, and I am currently stuck on having the form be generated from the dictionary. Could anyone here point me to the right direction?
Regards,
Jasper

CFWheels: Display form errors on redirectto instead of renderpage

I have a form which I am validating using CFWheels model validation and form helpers.
My code for index() Action/View in controller:
public function index()
{
title = "Home";
forms = model("forms");
allforms = model("forms").findAll(order="id ASC");
}
#startFormTag(controller="form", action="init_form")#
<select class="form-control">
<option value="">Please select Form</option>
<cfloop query="allforms">
<option value="#allforms.id#">#allforms.name#</option>
</cfloop>
</select>
<input type="text" name="forms[name]" value="#forms.name#">
#errorMessageOn(objectName="forms", property="name")#
<button type="submit">Submit</button>
#endFormTag()#
This form is submitted to init_form() action and the code is :
public function init_form()
{
title = "Home";
forms = get_forms(params.forms);
if(isPost())
{
if(forms.hasErrors())
{
// don't want to retype allforms here ! but index page needs it
allforms = model(tables.forms).findAll(order="id ASC");
renderPage(action="index");
//redirectTo(action="index");
}
}
}
As you can see from the above code I am validating the value of form field and if any errors it is send to the original index page. My problem is that since I am rendering page, I also have to retype the other variables that page need such as "allforms" in this case for the drop down.
Is there a way not to type such variables? And if instead of renderPage() I use redirectTo(), then the errors don't show? Why is that?
Just to be clear, I want to send/redirect the page to original form and display error messages but I don't want to type other variables that are required to render that page? Is there are way.
Please let me know if you need more clarification.
This may seem a little off topic, but my guess is that this is an issue with the form being rendered using one controller (new) and processed using another (create) or in the case of updating, render using edit handle form using update.
I would argue, IMHO, etc... that the way that cfWheels routes are done leaves some room for improvement. You see in many of the various framework's routing components you can designate a different controller function for POST than your would use for GET. With cfWheels, all calls are handled based on the url, so a GET and a POST would be handled by the same controller if you use the same url (like when a form action is left blank).
This is the interaction as cfwheels does it:
While it is possible to change the way it does it, the documentation and tutorials you'll find seem to prefer this way of doing it.
TL; DR;
The workaround that is available, is to have the form be render (GET:new,edit) and processing (POST:create,update) handled by the same controller function (route). Within the function...
check if the user submitted using POST
if it is POST, run a private function (i.e. handle_create()) that handles the form
within the handle_create() function you can set up all your error checking and create the errors
if the function has no errors, create (or update) the model and optionally redirect to a success page
otherwise return an object/array of errors
make the result error object/array available to view
handle the form creation
In the view, if the errors are present, show them in the form or up top somewhere. Make sure that the form action either points to self or is empty. Giving the submit button a name and value can also help in determining whether a form was submitted.
This "pattern" works pretty well without sessions.
Otherwise you can use the Flash, as that is what it was created for, but you do need to have Sessions working. their use is described here: http://docs.cfwheels.org/docs/using-the-flash and here:http://docs.cfwheels.org/v1.4/docs/flashmessages
but it really is as easy as adding this to your controller
flashInsert(error="This is an error message.");
and this to your view
<cfif flashKeyExists("error")>
<p class="errorMessage">
#flash("error")#
</p>
</cfif>

Django forms: checkboxes are displayed without value

I'm unable to save my form (a ModelForm) properly, since django displays checkboxes without a value (I would expect value="true" on every fields, both checked than unchecked... but that's not the case).
When I submit the form, no data is received in the POST!
The following is a piece o my template:
<div>
{{form.displayAge.label_tag}}
{{form.displayAge}}
{{form.displayAge.errors}}
</div>
{{form.displayAge}} is rendered in this way:
<input checked="checked" type="checkbox" name="displayAge" id="id_displayAge">
BUT... since it has no value, checking/unchecking the checkbox is helpless! What should I do?
I would like to avoid typing form fields by hand!
No, there is no need for a value field. If the checkbox is checked, the browser will submit "on" as the value by default if none is supplied.
If you're not getting this value in your view, something else is wrong. Note that since you're using Django forms, you shouldn't be checking request.POST manually anyway: use form.cleaned_data.