CODEWITHSUNDEEP
pythonflaskflask-wtforms
Terri Simon
Terri Simon

Reputation: 127

How can I pass a value into my Flask Form

I'm new to Flask. I've been looking at various tutorials and the only thing I've seen that looks like it should work doesn't.

I have a form class:

class CreateKardForm(FlaskForm):
kardTitle = StringField('Title')
contentText = TextAreaField('Content', [InputRequired(message="You must fill in some text.")])
keywords = StringField('Keywords', [InputRequired(message="Please enter at least one keyword. Separate keywords with commas.")])
createDate = DateField('Creation Date')
modifiedDate = DateField('Last Modified Date')
submit = SubmitField('Save')

And an html file:

<!DOCTYPE html>
<html lang="en">
{% extends "formbase.html" %}
{% block content %}
<div class="formwrapper>
    <h1>Create a New IdxKard</h1>
    <form action="" method="post" novalidate>
        {{ form.hidden_tag() }}
        ...
        <p>
            {{ form.createDate.label }}<br>
            {{ form.createDate }}
        </p>
        <p>
            {{ form.modifiedDate.label }}<br>
            {{ form.modifiedDate }}
        </p>
        <p>{{ form.submit() }}</p>
    </form>

</html>

{% endblock %}
</html>

And a route:

@app.route('/createKard', methods=['GET', 'POST'])
def createKard():
    print('In createKard')
    creationDate = datetime.now()
    print('creationDate=', creationDate)
    form = forms.CreateKardForm()

    if form.validate_on_submit():
        print('In createKard in main')

        title = request.form['kardTitle']
        content = request.form['contentText']
        keywords = request.form['keywords']
        createDate = request.form['createDate']
        modifiedDate = request.form['modifiedDate']

        # do stuff

    return render_template('createKard.html', createDate=creationDate, form=form)

I want that creationDate to show up in the form when it loads, but it doesn't. I suspect I am still fuzzy on exactly what is going on. I think because the user hasn't hit the submit button yet, that return with render_template should be displaying the HTML and passing in the createDate. When the user does hit the submit, the validate_on_submit is true and the rest of the code is run. Bottom line though, how do I pass a value into the form so it will be displayed?

Upvotes: 0

Views: 1029

Answers (1)

oschlueter
oschlueter

Reputation: 2698

Before passing the instance of CreateKardForm to render_template, you have to set its createDate.data:

@app.route('/createKard', methods=['GET', 'POST'])
def createKard():
    print('In createKard')
    creationDate = datetime.now()
    print('creationDate=', creationDate)
    form = forms.CreateKardForm()
    form.createDate.data = creationDate  # pre-populate the form
    
    # ...

    return render_template('createKard.html', createDate=creationDate, form=form)

Here is the result:

pre-populated form in browser

Upvotes: 1

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