This question could be a duplicate but I have checked all the answers of such related questions and I haven't been able to solve it.
I am trying to get the value from a dropdown menu which consists of numbers. Then I want to compare the numbers with a value and display a text based on the comparison.
Eg
if value_selected_from_dropdown >3
display text
I am unable to get the text to display or even print the value of the option selected.
Here is the python file, web_plants.py
from flask import Flask, render_template,request, redirect, url_for
app = Flask(__name__)
def template(title = "HELLO!", text = ""):
templateDate = {
'text' : text
}
return templateDate
@app.route("/threshold", methods=['POST'])
def threshold():
tvalue= (request.form.get['tvalue']) #get value from dropdown
msg= ""
if tvalue>3:
msg= "rating above 3"
templateData = template(text = msg) #display text using template()
#templateData = template(text = tvalue) #tried to print the value selected
return render_template('index.html', **templateData)
if __name__ == "__main__":
app.run(host='0.0.0.0', port=80, debug=True)
index.html:
<!DOCTYPE HTML>
<html>
<head>
<link rel="stylesheet" type="text/css" href="{{ url_for('static',filename='style.css')}}" />
</head>
<body>
<h2> {{ text }} </h2>
<form action= "{{ url_for('threshold') }}" method="post>"
<p>
<select name= 'tvalue'>
<option value="10">10</option>
<option value="11">11</option>
<option value="15">15</option>
<option value="2">2</option>
<option value="1">1</option>
</select>
</p>
</form>
</body>
</html>
There are several ways to achieve this. Either you can give logic to the template itself or you can add the logic in the function threshold.
index.html
<h2> {{text}} </h2>
<form action= "{{ url_for('threshold') }}" method="POST">
<select name= 'tvalue'>
{% for tvalue in tvalues %}
{% if selected_tvalue == tvalue %}
<option value="{{ tvalue }}" selected='selected'>{{ tvalue }}</option>
{% else %}
<option value="{{ tvalue }}" >{{ tvalue }}</option>
{% endif %}
{% endfor %}
</select>
<input type="submit" value="Submit" />
</form>
OR,
{% if selected_tvalue > 3 %}
<h2> Selected value is greater than 3 </h2>
{% else %}
<h2> Selected value is less than or equal to 3 </h2>
{% endif %}
<form action= "{{ url_for('threshold') }}" method="POST">
<select name= 'tvalue'>
{% for tvalue in tvalues %}
{% if selected_tvalue == tvalue %}
<option value="{{ tvalue }}" selected='selected'>{{ tvalue }}</option>
{% else %}
<option value="{{ tvalue }}" >{{ tvalue }}</option>
{% endif %}
{% endfor %}
</select>
<input type="submit" value="Submit" />
</form>
server.py
def template(title = "HELLO!", text = ""):
templateDate = {
'text' : text,
'tvalues' : getTValues(),
'selected_tvalue' : -1
}
return templateDate
def getTValues():
return (10, 11, 15, 2, 1)
@app.route("/threshold", methods=['POST', 'GET'])
def threshold():
tvalue= -1 #default value
msg = ''
if request.method == "POST":
tvalue = int(request.form['tvalue'])
if tvalue> 3:
msg= "rating above 3"
#generating template data
templateData = template(text = msg)
templateData['selected_tvalue'] = tvalue
return render_template('index.html', **templateData)
Then access your form at path /threshold. I hope it helps.
In your html after your drop down block you may need something like
<input type="submit">
which will trigger the submit. I am not sure, selecting a value alone triggers the form submit.
By the way where are you rendering your page initially ? I would have something like:
@app.route('/')
@app.route('/index')
def index():
return render_template('index.html')
in the python code. There to get the value, I would try
tvalue= request.args.get('tvalue')
Well not 'form' but 'args', and normal brackets instead of squared ones. Finally the function where you are going to handle that 'templateData' might be missing too.
last note:
you might need GET method too:
@app.route("/threshold", methods=['GET', 'POST'])
