Web developer specializing in React, Vue, and front end development.
To add a form to a dynamically to a Django formset, we can use a for loop.
For instance, we write
<h3>My Services</h3>
{{ serviceFormset.management_form }}
{% for form in serviceFormset.forms %}
<div class='table'>
<table class='no_error'>
{{ form.as_table }}
</table>
</div>
{% endfor %}
<input type="button" value="Add More" id="add_more">
to render the forms with form.as_table within the for loop.
We get the forms from serviceFormset.forms .
To add a numeric for loop in python Django templates, we can add it straight into the template.
For instance, we write
{% for i in '0123456789'|make_list %}
{{ forloop.counter }}
{% endfor %}
to add a for loop in our template that loops from 0 to 9 since we have in '0123456789' as the loop expression.
We use the make_list filter to convert '0123456789' into a list.
Then we use forloop.counter to get the index.
To look up a dictionary value with a variable with a Python Django template, we can add a custom template filter.
For instance, we write
from django.template.defaulttags import register
##...
@register.filter
def get_item(dictionary, key):
return dictionary.get(key)
to use the register_filter decorator to add the get_item template filter.
In it, we call dictionary.get with the key to return the value of the given key.
Then we use it by using
{{ mydict|get_item:item.NAME }}
in our template
We use get_item with item.NAME we the key and mydict as the dictionary value.
To fix ‘CORS: Cannot use wildcard in Access-Control-Allow-Origin when credentials flag is true’ with Express and JavaScript, we can change the config of the cors middleware.
For instance, we write
const app = express();
const corsConfig = {
credentials: true,
origin: true,
};
app.use(cors(corsConfig));
to set the credentails and origin options to true when we add the cors middleware in our Express app to avoid this error.
To upload a file in Python Django, we can get the upload files from request.FILES.
For instance, we write
for key, file in request.FILES.items():
path = file.name
dest = open(path, 'w')
if file.multiple_chunks:
for c in file.chunks():
dest.write(c)
else:
dest.write(file.read())
dest.close()
to loop through the request.FILES dictionary in our view function.
And then we can write the files into disk with write.
We can add a simple upload form with
<form action="/upload_file/" method="post" enctype="multipart/form-data">
{% csrf_token %}
<label for="file">Filename:</label>
<input type="file" name="file" id="file" />
<br />
<input type="submit" name="submit" value="Submit" />
</form>
which has a file input.
The action attribute of the form is set to the URL of the file upload view.