I'm struggling with a Flask App that gives me Bad Request on a form submission. I've been through the little bit of documentation from Flask and a number of SO pages. I'm sure there's something simple I'm missing.
In a nutshell, I've developed a template to receive the form called 'placeindex.html'. The form 'name' data all matches. If I change the name of 'placeindex.html' to 'index.html' it works fine, even though I'm pointing to the 'placeindex.html' file. Code below (view):
#app.route('/add_place', methods=['GET', 'POST'])
def add_place():
username = session['username']
placename = request.form['place']
address = request.form['address']
city = request.form['city']
state = request.form['state']
zipcode = request.form['zipcode']
alias = request.form['alias']
searchword = request.args.get('key', '')
print(searchword)
Place(session['username']).new_place(placename, address, city, state, zipcode, alias, username)
return render_template('placeindex.html')
placeindex.html:
{% extends "layout.html" %}
{% block place %}
<h2>Home</h2>
{% if session.username %}
<h3>Add new 'placeindex'</h3>
<form action="{{ url_for('add_place') }}" method="post">
<dl>
<dt>Name:</dt>
<dd><input type="text" size="30" name="place"></dd>
<dt>Address:</dt>
<dd><input type="text" size="30" name="address"></dd>
<dt>City:</dt>
<dd><input type="text" size="30" name="city"></dd>
<dt>State:</dt>
<dd><input type="text" size="2" name="state"></dd>
<dt>Zip Code:</dt>
<dd><input type="text" size="10" name="zipcode"></dd>
<dt>Nickname:</dt>
<dd><input type="text" size="30" name="alias"></dd>
</dl>
<input type="submit" value="Save">
</form>
{% endif %}
<br>
<h3>My Places</h3>
{% include "display_posts.html" %}
{% endblock %}
I've stripped out all the validation code to try to figure this out.
layout.html (in case it helps):
<!doctype html>
<link rel="stylesheet" type="text/css" href="{{ url_for('static', filename='style.css') }}">
<div class="page">
<div class="metanav">
{% if session.username %}
Logged in as {{ session.username }}
{% endif %}
Home
{% if not session.username %}
Register
Login
{% else %}
Profile
Logout
Places
Trips
Delegates
{% endif %}
</div>
{% for message in get_flashed_messages() %}
<div class="flash">{{ message }}</div>
{% endfor %}
{% block body %}{% endblock %}
{% block post %}{% endblock %}
{% block place %}{% endblock %}
{% block trip %}{% endblock %}
</div>
Once I open the 'index.html' version of the file and send form data, it refreshes to the correct file, but I can't go there directly without the BAD REQUEST page.
Thanks
The issue is that you are accessing request.form without checking if request.form is populated. form contains arguments in the body of the HTTP request ... and GET requests don't have a body.
As discussed in Form sending error, Flask - when Flask is asked for a form variable that doesn't exist it throws an error ... just like an ordinary Python dictionary does.
The solution in your case is to wrap all of your data-processing code inside of a conditional:
if request.method == "POST":
# code accessing request.form here
So the general structure is:
#app.route('/add_place', methods=['GET', 'POST'])
def add_place():
if request.method == "POST":
username = session['username']
placename = request.form['place']
# ... snip ...
# Note that this is not under the `if`
# so we'll *always* return this template's HTML.
return render_template('placeindex.html')
Related
Apologies if this isn't worded very well. I can't seem to get any error messages to show when I haven't fulfilled the validation requirements. When I submit, the form is just refreshed without error messages such as "This field is required".
Also, when I do input data, if form.validate_on_submit(): doesn't return the expected homepage, it once again just refreshes the page. I'm aware the form does nothing, I plan on adding the data submitted to a database but I'm stuck on this step. Can anybody help? Thanks.
app.py
from cs50 import SQL
from flask import Flask, render_template, session, redirect
from flask_session import Session
from flask_wtf import FlaskForm
from wtforms import StringField, PasswordField, BooleanField #bool for checkbox
from wtforms.validators import InputRequired, Email, Length
# configure application
app = Flask(__name__)
app.config["SESSION_PERMENANT"] = False
app.config["SESSION_TYPE"] = "filesystem"
Session(app)
# Allows webpage to update html on refresh
app.config["TEMPLATES_AUTO_RELOAD"] = True
app.config['SECRET_KEY'] = 'Itsasecret'
# configure CS50 library to use SQLite database
db = SQL("sqlite:///project.db")
# Usually separate routes, database and form stuff into different files and link together
class LoginForm(FlaskForm):
username = StringField('Username', validators=[InputRequired(), Length(min=4, max=15)])
password = PasswordField('Password', validators=[InputRequired(), Length(min=8, max=80)]) #80 is a special number (learn more)
remember = BooleanField('Remember me')
#app.route('/')
def homepage():
return render_template("homepage.html")
#app.route('/login', methods=['GET', 'POST'])
def login():
form = LoginForm()
if form.validate_on_submit():
return redirect("/")
return render_template("login.html", form=form)
login template
{% extends "layout.html" %}
{% from "_formhelpers.html" import render_field %}
{% set active_page = 'login' %}
{% block title %} Login {% endblock %}
{% block body %}
<div class="ls-main">
<form action="/login" method="POST">
{{ form.csrf_token }}
{{ render_field(form.username) }}
{{ render_field(form.password, autocomplete="off") }}
{{ render_field(form.remember) }}
<div class="ls-div">
<input class="ls-input, signinbutton" name="submit" type="submit" value="Submit">
</div>
</form>
</div>
{% endblock %}
_formhelpers.html
{% macro render_field(field) %}
<dt>{{ field.label }}
<dd>{{ field(**kwargs)|safe }}
{% if field.errors %}
<ul class=errors>
{% for error in field.errors %}
<li>{{ error }}</li>
{% endfor %}
</ul>
{% endif %}
</dd>
{% endmacro %}
return render_template("/") is invalid. I think you mean return redirect("/")
Of course you need from flask import Flask, render_template, session, redirect
I would like to display form error message inside bootstrap tooltip.
<div class="btn-upload" data-toggle="tooltip" data-html="true" data-title="{% if document.documentFile.vars.errors|length > 0 %}<span class='text-danger'>{{ form_errors(document.documentFile) }}</span>{% endif %}">
It should display form error inside tooltip on icon.
But message is displayed like this:
Now if I change {{ form_errors(document.documentFile) }} to "TEST MESSAGE":
So the problem is form error rendering inside tooltip. Any ideas how to fix it?
The {{ form_errors(document.documentFile) }} renders HTML with " that breaks your div.
Consider doing this :
<div class="btn-upload" data-toggle="tooltip" data-html="true" id="error-tooltip">
<script type="text/html" id="form-error">
{% if document.documentFile.vars.errors|length > 0 %}
<span class='text-danger'>{{ form_errors(document.documentFile) }}</span>
{% endif %}
</script>
<!-- ... -->
</div>
And, in your JS :
$('#error-tooltip').data('tooltip', $('#form-error').html());
I finally figured out a simplier way to achieve it by foreaching errors of document.documentFile.vars.errors. A little bit similar way to Favian's answer but without rewriting a block.
<div class="btn-upload" data-toggle="tooltip"
{% if document.documentFile.vars.errors|length > 0 %}
data-html="true"
data-title="<span class='text-danger'>
{% for error in document.documentFile.vars.errors %}
{{ error.message }}
{% endfor %}
</span>"
{% endif %}
>
Works just fine!
By default, the errors are rendered inside an unordered list:
<ul>
<li>The file is to large bla bla bla</li>
</ul>
To override how errors are rendered for all fields, simply copy, paste and customize the form_errors fragment.
<div class="btn-upload" data-toggle="tooltip" data-html="true" data-title="{% if document.documentFile.vars.errors|length > 0 %}<span class='text-danger'>
{% block form_errors %}
{% spaceless %}
{% if errors|length > 0 %}
{% for error in document.documentFile %}
{{ error.message }}
{% endfor %}
{% endif %}
{% endspaceless %}
{% endblock form_errors %}
</span>{% endif %}">
</div>
I was sure I understand this process, but when I dug deeper I saw I am wrong ;(
Let's take simple form, please notice that this form contains 3 fields
$form = $this->createFormBuilder($defaultData, ['csrf_protection' => false])
->add('email', 'email')
->add('name', 'text')
->add('message', 'textarea')
->getForm()
->createView();
which is rendered as
{{ form(form, {'attr': {'novalidate': 'novalidate'}}) }}
into
Built in "form" block from vendor\symfony\symfony\src\Symfony\Bridge\Twig\Resources\views\Form\form_div_layout.html.twig looks like:
{% block form %}
{% spaceless %}
{{ form_start(form) }}
{{ form_widget(form) }}
{{ form_end(form) }}
{% endspaceless %}
{% endblock form %}
and form_widget(form)
{% block form_widget %}
{% spaceless %}
{% if compound %}
{{ block('form_widget_compound') }}
{% else %}
{{ block('form_widget_simple') }}
{% endif %}
{% endspaceless %}
{% endblock form_widget %}
{% block form_widget_simple %}
{% spaceless %}
{% set type = type|default('text') %}
<input type="{{ type }}" {{ block('widget_attributes') }} {% if value is not empty %}value="{{ value }}" {% endif %}/>
{% endspaceless %}
{% endblock form_widget_simple %}
Let's modify form and form_widget a bit:
{% block form %}
{% spaceless %}
{{ form_start(form) }}
-form_widget before-
{{ form_widget(form) }}
-form_widget after-
{{ form_end(form) }}
{% endspaceless %}
{% endblock form %}
{% block form_widget %}
{% spaceless %}
- form_widget call -
{% if compound %}
- form_widget compound-
{{ block('form_widget_compound') }}
{% else %}
- form_widget simple-
{{ block('form_widget_simple') }}
{% endif %}
{% endspaceless %}
{% endblock form_widget %}
then as an output I got (listing 5):
<form name="form" method="post" action="" novalidate="novalidate">
-form_widget before-
- form_widget call -
- form_widget compound-
<div id="form" novalidate="novalidate">
<div>
<label for="form_email" class="required">Email</label>
<input type="email" id="form_email" name="form[email]" required="required" />
</div>
<div>
<label for="form_name" class="required">Name</label>
- form_widget call -
- form_widget simple-
<input type="text" id="form_name" name="form[name]" required="required" />
</div>
<div>
<label for="form_message" class="required">Message</label>
<textarea id="form_message" name="form[message]" required="required">Type your message here</textarea>
</div>
</div>
-form_widget after-
</form>
we can easly notcie the flow
form -> form_widget (input parameter is the whole form) -> form_widget_compound -> form_rows (iterates form elements into next function) -> form_row -> form_widget (this call form element is passed as parameter)
so here is the time for question, if form_widget is called 4 times (or more), once for form, 3 times for fields then why in listing 5 'form_widget call' text appears only 2 times?
or other words how email and message were rendered?
The form theming in SF2 uses inheritance. That means that if blocks named email_widget and textarea_widget are defined, neither your e-mail nor your textarea fields will use form_widget. They will rather respectively use their own widget blocks: email_widget and textarea_widget.
Well, in form_div_layout.twig, these two widget blocks are defined. Thus form_widget is not called for 2 of your fields. Thus your message is displayed 2 times instead of 4.
If you want to customize the rendering of these fields, you will have to create your own block definitions email_widget and textarea_widget in your custom form theme file.
Edit:
The default form theme files are defined under Symfony\Bridge\Twig\Resources\views\Form. The default file used is form_div_layout.html.twig.
Although the inheritance logic itself is indeed in the PHP code of the TWIG bridge, it does not define which block inherit from which other block.
Inheritance is actually defined in your FormType classes. Each form type class sports a getParent() method that return the name of the form from which it inherits. The name of a form type is the result of the method getName() of its associated form type class. For instance, with a built-in example, Symfony\Component\Form\Extension\Core\Type\TextareaType:
Textarea >> Text >> Field >> Form
All you have to do is to look for the methods getParent() and getName(). Thus, by default, when rendering the textarea row, Twig will search the block textarea_row, text_row, field_row and finally form_row (the base default row). The first of these blocks that is defined in your form theme is rendered.
The definition of the blocks themselves happen in the form theme files.
I need to be able to add a CSS class to each individual radio button of my choice field(s). Unfortunately, Symfony2 stuffs expanded choices in a div, which gets any passed in CSS class rather than the buttons themselves.
Here's the default widget theming (in PHP):
<div <?php echo $view['form']->block($form, 'widget_container_attributes') ?>>
<?php foreach ($form as $child): ?>
<?php echo $view['form']->widget($child) ?>
<?php echo $view['form']->label($child) ?>
<?php endforeach ?>
</div>
Here's my div-less version (in twig):
{% block choice_widget_expanded %}
{% for child in form %}
{{ form_widget(child) }}
{{ form_label(child) }}
{% endfor %}
{% endblock %}
With that, how can I pass the CSS class to the actual widget? I'm passing it in like:
{% form_widget(form.blah, { 'attr' : { 'class': 'css-class' } }) %}
In my view, but I'm not sure how to grab it in my widget theme.
I can't not use radio buttons for this, so telling me to switch to a select or checkboxes isn't an option. And I really, really don't want to hard code the radios into my form view if I can help it.
EDIT: I've tried:
{% block choice_widget_expanded %}
{% for child in form %}
<input type="radio" value="{{ child.vars.value }}" {{ block('widget_attributes') }} />
{% endfor %}
{% endblock %}
Yet it still renders a containing div in the source, and passes my CSS class to that div instead of the radio inputs. I know that the theme is 'working' because I had a few exceptions thrown during my fiddling.
EDIT 2: With the suggestion below, I've created my own radio_widget theme:
{% block radio_widget %}
<input type="radio" class="star {split:2}" {{ block('widget_attributes') }} value="{{ value }}" {% if checked == true %}checked="checked"{% endif %} />
{% endblock %}
But, unfortunately, it's not generating the radios with the class I added above. I'm not sure if I need to do some inheritance work.
Interesting, why you want every radio option to have a class attribute. But...
Because choice is a single field (no matter how many options it has) you can add class to the wrapper div only. For the theming you should use CSS.
Speaking about form theming if you want to override radio option you should override block radio_widget (you can find original one in form_div_layout.html.twig)
And of course don't forget to tell you template to use form theme:
{% form_theme form _self %}
Since umpteens days, I block on a problem with Symfony 2 and forms.
I got a form of websites entities. "Websites" is a collection of website's entities and each website contains two attributes : "type" and "url".
If I want to add more of one website in my database, I can click on a "Add another website" link, which add another website row to my form. So when you click on the submit button, you can add one or X website(s) at the same time.
This process to add a row use the data-prototype attribute, which can generate the website sub-form.
The problem is that I customize my form to have a great graphic rendering... like that :
<div class="informations_widget">{{ form_widget(website.type.code) }}</div>
<div class="informations_error">{{ form_errors(website.type) }}</div>
<div class="informations_widget">{{ form_widget(website.url) }}</div>
<div class="informations_error">{{ form_errors(website.url) }}</div>
But the data-prototype doesn't care about this customization, with HTML and CSS tags & properties. I keep the Symfony rendering :
<div>
<label class=" required">$$name$$</label>
<div id="jobcast_profilebundle_websitestype_websites_$$name$$">
<div>
<label class=" required">Type</label>
<div id="jobcast_profilebundle_websitestype_websites_$$name$$_type">
<div>
<label for="jobcast_profilebundle_websitestype_websites_$$name$$_type_code" class=" required">label</label>
<select id="jobcast_profilebundle_websitestype_websites_$$name$$_type_code" name="jobcast_profilebundle_websitestype[websites][$$name$$][type][code]" required="required">
<option value="WEB-OTHER">Autre</option>
<option value="WEB-RSS">Flux RSS</option>
...
</select>
</div>
</div>
</div>
<div>
<label for="jobcast_profilebundle_websitestype_websites_$$name$$_url" class=" required">Adresse</label>
<input type="url" id="jobcast_profilebundle_websitestype_websites_$$name$$_url" name="jobcast_profilebundle_websitestype[websites][$$name$$][url]" required="required" value="" />
</div>
</div>
</div>
Does anyone have an idea to make that hack ?
A bit old, but here is a deadly simple solution.
The idea is simply to render the collection items through a Twig template, so you have full ability to customize the prototype that will be placed in your data-prototype="..." tag. Just as if it was a normal, usual form.
In yourMainForm.html.twig:
<div id="collectionContainer"
data-prototype="
{% filter escape %}
{{ include('MyBundle:MyViewsDirectory:prototype.html.twig', { 'form': form.myForm.vars.prototype }) }}
{% endfilter %}">
</div>
And in MyBundle:MyViewsDirectory:prototype.html.twig:
<div>
<!-- customize as you wish -->
{{ form_label(form.field1) }}
{{ form_widget(form.field1) }}
{{ form_label(form.field2) }}
{{ form_widget(form.field2) }}
</div>
Credit: adapted from https://gist.github.com/tobalgists/4032213
I know this question is quite old, but I had the same problem and this is how I soved it. I'm using a twig macro to accomplish this. Macros are like functions, you can render them with different arguments.
{% macro information_prototype(website) %}
<div class="informations_widget">{{ form_widget(website.type.code) }}</div>
<div class="informations_error">{{ form_errors(website.type) }}</div>
<div class="informations_widget">{{ form_widget(website.url) }}</div>
<div class="informations_error">{{ form_errors(website.url) }}</div>
{% endmacro %}
now you can render this macro wherever you want. Note that information_prototype() is just the name of the macro, you can name it whatever you want. If you want to use the macro to render the given items and the prototype the same way, do something like this:
<div class="collection" data-prototype="{{ _self.information_prototype(form.websites.vars.prototype)|e }}">
{% for website in form.websites %}
{{ _self.information_prototype(website) }}
{% endfor %}
<button class="add-collection">Add Information</button>
</div>
form.websites.vars.prototype holds the prototype data of the form with the prototype_name you specified. Use _self.+macroname if you want to use the macro in the same template.
You can find out more about macros in the Twig documentation
You probably have found out since but here is the solution for others.
Create a new template and copy/paste this code in it:
https://gist.github.com/1294186
Then in the template containing the form you want to customise, apply it to your form by doing this:
{% form_theme form 'YourBundle:Deal:Theme/_field-prototype.html.twig' %}
I've run into similar problem recently. Here's how you can override the collection prototype without having to explicitly set it in the html:
{% set customPrototype %}
{% filter escape %}
{% include 'AcmeBundle:Controller:customCollectionPrototype.html.twig' with { 'form': form.collection.vars.prototype } %}
{% endfilter %}
{% endset %}
{{ form_label(form.collection) }}
{{ form_widget(form.collection, { 'attr': { 'data-prototype': customPrototype } }) }}
You can do whatever you want then in your custom twig. For example:
<div data-form-collection="item" data-form-collection-index="__name__" class="collection-item">
<div class="collection-box col-sm-10 col-sm-offset-2 padding-top-20">
<div class="row form-horizontal form-group">
<div class="col-sm-4">
{{ form_label(form.field0) }}
{{ form_widget(form.field0) }}
</div>
<div class="col-sm-3">
{{ form_label(form.field1) }}
{{ form_widget(form.field1) }}
</div>
<label class="col-sm-3 control-label text-right">
<button data-form-collection="delete" class="btn btn-danger">
<i class="fa fa-times collection-button-remove"></i>{{ 'form.collection.delete'|trans }}
</button>
</label>
</div>
</div>
Useful when you only have to do it in specific places and don't need a global override that's applicable to all collections.
I know that answer is very late but it maybe useful for visitors.
on your theme file you can simply use one block for rendering every collection entry of websites widget as following:
{% block _jobcast_profilebundle_websitestype_websites_entry_widget %}
<div class="informations_widget">{{ form_widget(form.type.code) }}</div>
<div class="informations_error">{{ form_errors(form.type) }}</div>
<div class="informations_widget">{{ form_widget(form.url) }}</div>
<div class="informations_error">{{ form_errors(form.url) }}</div>
{% endblock %}
also create theme block for your collection widget row as following:
{% block _quiz_question_answers_row %}
{% if prototype is defined %}
{%- set attr = attr | merge({'data-prototype': form_row(prototype) }) -%}
{% endif %}
{{ form_errors(form) }}
{% for child in form %}
{{ form_row(child) }}
{% endfor %}
{% endblock %}
now the prototype and the rendered collection entry will be the same.
I had a somewhat similar issue. You might have to tweak this to work for your case, but someone may find it helpful.
Create a new template file to hold your custom form 'theme'
./src/Company/TestBundle/Resources/views/Forms/fields.html.twig
Normally, you can use the form_row function to display a field's label, error, and widget. But in my case I just wanted to display the widget. As you say, using the data-prototype feature would also display the label, so in our new fields.html.twig type your custom code for how you want the field to look:
{% block form_row %}
{% spaceless %}
{{ form_widget(form) }}
{% endspaceless %}
{% endblock form_row %}
I removed the container div, and the label and error, and just left the widget.
Now in the twig file that displays the form, simply add this after the {% extends ... %}
{% form_theme form 'CompanyTestBundle:Form:fields.html.twig' %}
And now the form_widget(form.yourVariable.var.prototype) will only render the field and nothing else.
Application wide form theming will be applied to the prototype.
See Making Application-wide Customizations
Here is sample code for custom data-prototype:
{{ form_widget(form.emails.get('prototype')) | e }}
where emails — your collection.
To customize differently existing collection items VS prototype, you can override collection_widget like this:
{%- block collection_widget -%}
{% if prototype is defined %}
{%- set attr = attr|merge({'data-prototype': form_row(prototype, {'inPrototype': true} ) }) -%}
{% endif %}
{{- block('form_widget') -}}
{%- endblock collection_widget -%}
And then in your custom entry:
{% block _myCollection_entry_row %}
{% if(inPrototype is defined) %}
{# Something special only for prototype here #}
{% endif %}
{% endblock %}
If you do not need to define a template system-wide, simply set a template in your twig template, and ask twig to use it.
{# using the profiler, you can find the block widget tested by twig #}
{% block my_block_widget %}
<div >
<p>My template for collection</p>
<div >
{{ form_row(form.field1)}}
</div>
<div>
{{ form_row(form.field2)}}
</div>
</div>
{% endblock %}
{% form_theme form.my_collection _self %}
<button data-form-prototype="{{ form_widget(form.my_collection.vars.prototype) )|e }}" >Add a new entry</button>
There are two blocks that you can possibly target to add a custom theme to a collection field:
_myCollection_row and _myCollection_entry_row
_myCollection_row - renders the whole collection.
_myCollection_entry_row - renders a single item.
The prototype relies on _myCollection_entry_row so if you theme _myCollection_row only your theme will appear in the form, but not the prototype. The prototype uses _myCollection_entry_row.
So it's best to theme _myCollection_entry_row first, and then theme _myCollection_row only if required. BUT - if you theme _myCollection_row make sure it calls _myCollection_entry_row to render each item in your collection.
This post focuses on using pre-existing conventions within the twig template.
Basing off "How to Embed a Collection of Forms" from the Symfony Cookbook (http://symfony.com/doc/master/cookbook/form/form_collections.html), you can just enter whatever html_escaped form data you wish in the data-prototype (maybe considered a hack, but works wonderfully) and only pages using that template will change.
In the example, they tell you to put:
<ul class="tags" data-prototype="{{ form_widget(form.tags.vars.prototype)|e }}">
...
</ul>
This can be successfully replaced with something such as:
<table class="tags" data-prototype="<tr> <td><div><input type="text" id="task_tags__name__tagId" name="task[tags][__name__][taskId]" disabled="disabled" required="required" size="10" value="" /></div></td> <td><div><input type="text" id="task_tags__name__tagName" name="task[tags[__name__][tagName]" required="required" value="" /></div></td></tr>">
<tr>
<th>Id</th>
<th>Name</th>
</tr>
<tr>
...pre existing data here...
</tr>
</table>
Where the data-type attribute of the table with the class "tags" above is the html-escaped version (and line breaks removed though spaces are ok and required) of:
<tr>
<td><div><input type="text" id="task_tags__name__tagId" name="task[tags][__name__][taskId]" disabled="disabled" required="required" size="10" value="" /></div></td>
<td><div><input type="text" id="task_tags__name__tagName" name="task[tags[__name__][tagName]" required="required" value="" /></div></td>
</tr>
...but you must also adjust the javascript in the example to add tr's instead of li elements:
function addTagForm(collectionHolder, $newLinkTr) {
...
// Display the form in the page in an tr, before the "Add a question" link tr
var $newFormTr = $('<tr></tr>').append(newForm);
...
};
...
// setup an "add a tag" link
var $addTagLink = $('Add a tag');
var $newLinkTr = $('<tr></tr>').append($addTagLink);
...
For me, the next step is figuring out how to define the prototype in an external file that I can somehow call in the twig template for the data-prototype that dynamically works with the form. Something like:
<table class="tags" data-prototype="{{somefunction('App\Bundle\Views\Entity\TagsPrototypeInTable')}}">
So if one of the other posts is describing this and I am too dense or if someone knows how to do such, say so!
There is a link to something from gitHub from Francois, but I didn't see any explanation so I think that is probably the more dynamic method I'll get to one of these near-future days.
Peace,
Steve
Update:
One can also use just parts of the prototype:
data-prototype="<tr> <td>{{ form_row(form.tags.vars.prototype.tagId) | e }}</td> <td>{{ form_row(form.tags.vars.prototype.tagName) | e }}</td></tr>"
Where the data-type attribute of the table with the class "tags" above is the html-escaped version (and line breaks removed though spaces are ok and required) of:
<td>{{ form_row(form.tags.vars.prototype.tagId) | e }}</td>
<td>{{ form_row(form.tags.vars.prototype.tagName) | e }}</td>
(I used http://www.htmlescape.net/htmlescape_tool.html.)
Symfony will replace the information between the {{}} with an html_escaped (because of the "|e") rendered field when the page is rendered. In this way, any customization at the field-level is not lost, but! you must manually add and remove fields to the prototype as you do so with the entity :)