Question

On Google app engine, I’d like to use two variables in a template for loop: I need to input, say, 10 items. If there are already some items in the datastore, then show them, otherwise, leave the field blank. How do I do it? Thanks.

BTW, I noticed that there is “multifor” in Django, but I don’t know how to install it on GAE.

main.py:

def mainPage(webapp2.RequestHandler):
    query = db.Query(Item)
    items = query.fetch(limit=10)
    template_values = {'range': range(10), 'items': items}
    common.render(handler, 'main.html', template_values)

main.html:

<form action=... method="post">
      {% for i in range; for item in items %}
        <input type="text" name="name" value="item.name">
      {% endfor %}
      <input type="submit">
</form>

Answer 1

Not sure which templating engine you are using, but what about creating a list of 10-elements and filling it with the results of your query? Something like:

my_list = [None for _ in range(10)]

Then, once you get your query results, add them to the list (the objects will be returned as a list of objects, so this is just a conceptual example):

>>> new_list = ['one', 'two', 'three']
>>> my_list[:len(new_list)] = new_list
>>> my_list
['one', 'two', 'three', None, None, None, None, None, None, None]

Now when you pass my_list into the template:

<form action=... method="post">
      {% for item in my_list %}
        {% if item %}
           <input type="text" name="name" value="item.name">
        {% else %}
           <input type="text" name="<your_blank_value>" value="<your_blank>">
        {% endif %}
      {% endfor %}
      <input type="submit">
</form>