Skip to content

Latest commit

 

History

History
101 lines (77 loc) · 4.83 KB

6_nextquestion.rst

File metadata and controls

101 lines (77 loc) · 4.83 KB
Raw

Linking to the next question

To link one question to the next, we need to tell the server what to do when /next_lulu is requested. This will be a POST request, because we want to take data from the user.

Open application_lulu.py and add this decorated function:

@app_lulu.route('/next_lulu',methods=['POST'])
def next_lulu():  #remember the function name does not need to match the URL
    return render_template('layout_lulu.html',num=1,question='Which fruit do you like best?',ans1='banana',\
        ans2='mango',ans3='pineapple')

In case it isn't clear, the whole file application_lulu.py should now look like:

from flask import Flask,render_template,request
app_lulu = Flask(__name__)

app_lulu.vars={}

@app_lulu.route('/index_lulu',methods=['GET','POST'])
def index_lulu():
    nquestions=5
    if request.method == 'GET':
        return render_template('userinfo_lulu.html',num=nquestions)
    else:
        #request was a POST
        app_lulu.vars['name'] = request.form['name_lulu']
        app_lulu.vars['age'] = request.form['age_lulu']

        f = open('%s_%s.txt'%(app_lulu.vars['name'],app_lulu.vars['age']),'w')
        f.write('Name: %s\n'%(app_lulu.vars['name']))
        f.write('Age: %s\n\n'%(app_lulu.vars['age']))
        f.close()

        return render_template('layout_lulu.html',num=1,question='How many eyes do you have?',ans1='1',\
            ans2='2',ans3='3')

@app_lulu.route('/next_lulu',methods=['POST'])
def next_lulu():  #remember the function name does not need to match the URL
    return render_template('layout_lulu.html',num=1,question='Which fruit do you like best?',ans1='banana',\
        ans2='mango',ans3='pineapple')

if __name__ == "__main__":
    app_lulu.run(port=5001, debug=True)

Try running it. IT WORKS, RIGHT? But, when you click on Next after the fruit question, what do you get? IT'S THE FRUIT QUESTION AGAIN. How can we fix this? We need to somehow tell the application to keep track of the questions being asked. We can make a list of questions at the beginning, then iterate through them.

What will come in handy now is to learn about the redirect function in Flask. There's also url_for, which you can Google yourself. It's not necessary for now.

Redirecting

The redirect function in Flask allows a decorated function (a function with @app_lulu.route('/index_lulu') or similar preceding the function) to return the HTML template that another function will produce. Instead of calling render_template to make an HTML page, we call redirect and insert the URL for another decorator function, which will call that decorated function and return the associated HTML code.

Here's an example. We take the previous code and we just add one more step, which redirects to another function to give the rendered template:

from flask import Flask,render_template,request,redirect
app_lulu = Flask(__name__)

app_lulu.vars={}

@app_lulu.route('/index_lulu',methods=['GET','POST'])
def index_lulu():
    nquestions=5
    if request.method == 'GET':
        return render_template('userinfo_lulu.html',num=nquestions)
    else:
        #request was a POST
        app_lulu.vars['name'] = request.form['name_lulu']
        app_lulu.vars['age'] = request.form['age_lulu']

        f = open('%s_%s.txt'%(app_lulu.vars['name'],app_lulu.vars['age']),'w')
        f.write('Name: %s\n'%(app_lulu.vars['name']))
        f.write('Age: %s\n\n'%(app_lulu.vars['age']))
        f.close()

        return render_template('layout_lulu.html',num=1,question='How many eyes do you have?',ans1='1',\
            ans2='2',ans3='3')

@app_lulu.route('/next_lulu',methods=['POST'])
def next_lulu():
    return redirect('/usefulfunction_lulu')
@app_lulu.route('/usefulfunction_lulu',methods=['GET','POST'])
def usefulfunction_lulu():
    return render_template('layout_lulu.html',num=1,question='Which fruit do you like best?',ans1='banana',\
        ans2='mango',ans3='pineapple')

if __name__ == "__main__":
    app_lulu.run(port=5001, debug=True)

I think that's most of the FLASK-ESQUE stuff. The rest is all PYTHON. In the next section, we'll put some of this stuff together, using Python dictionaries to make the question-asking scalable (easier to add more questions), and to automate the process for many questions.