Jinja - Nested for statement inside of an if statement-CodePudding

I am trying to create a table that contains all of the records found inside of a query but only when the said query returns records.

{% if l > 0 %}
{% for record in precord %}
    <tr> 
        <td colspan=1>{{ record['date'] }}</td>
        <td colspan=2>{{ record['tasknote'] }}</td>
    </tr>
{% endfor %}
{% else %}
    <tr>
        <td colspan=3><center>No previous contacts. Get working!</center></td>
    </tr>
{% endif %}

l is equal to the amount of records found. I have tested this by calling l inside of the if loop and it does/doesn't fire based upon the correct amount of records.

My issue is I am not able to get the table row to print. It works perfectly fine without the count test, but as soon as I add the wrapper it doesn't. I feel like I am missing a syntax error, but I've looked through the documentation and can't seem to find out what is going on.

Edited to add code that renders template:

@app.route('/view/<id>', methods=["GET", "POST"])
@login_required
def view(id):
    form = CreatePR()
    record = people.find_one({"_id": ObjectId(id)})
    precord = history.find({"parentRecord": str(record['_id'])}).sort('date',pymongo.ASCENDING)
    listl = len(list(precord))

    if request.method == "GET":
        return render_template('view.html', form=form, people=record, precord=precord, auth=current_user.is_authenticated, id=id, l=listl)
    
    elif request.method == "POST":
        date = request.form.get('date')
        tasknote = request.form.get('tasknote')
        adate = datetime.today()
        
        history.insert_one({"date": date, "tasknote": tasknote, "dateAdded": adate.strftime("%x"), "parentRecord": id})
        flash('Your record has been added successfully.')
        return redirect(url_for('view', id=id))

CodePudding user response：

There is already a specific construct for this type of case: Jinja does have a for ... else ... implementation:

{% for record in precord | default([], true) %}
  <tr> 
    <td colspan="1">{{ record.date }}</td>
    <td colspan="2">{{ record.tasknote }}</td>
  </tr>
{% else %}
  <tr>
    <td colspan="3">
      <center>No previous contacts. Get working!</center>
    </td>
  </tr>
{% endfor %}