Form, views and templates¶
The goal of this tutorial is to add data to Invenio v3. We’ll create a form that inserts the data in the database. Also we will touch different part of the development process such as:
- How to create a new view
- How to create a form
- How to add a utility function
- How to add new templates
- How to use Jinja2
Flask extensions¶
It is important to understand that Invenio modules are just regular Flask extensions. The Flask documentation contains extensive documentation on the APIs, design patterns and in general how to develop with Flask, and it is highly recommended that you follow Flask tutorials to understand the basics of Flask.
1. Create the form¶
First, let’s create a module that contains the forms of our project, we will use Flask-WTF.
in invenio_unicorn/forms.py
"""Forms module."""
from __future__ import absolute_import, print_function
from flask_wtf import FlaskForm
from wtforms import StringField, TextAreaField, validators
class RecordForm(FlaskForm):
"""Custom record form."""
title = StringField(
'Title', [validators.DataRequired()]
)
description = TextAreaField(
'Description', [validators.DataRequired()]
)
2. Create the views¶
in invenio_unicorn/views.py
we’ll create the endpoints for
create
: Form templatesuccess
: Success template
The views.py
registers all the views of our application
"""Invenio module that adds more fun to the platform."""
from __future__ import absolute_import, print_function
from flask import Blueprint, redirect, render_template, request, url_for
from flask_babelex import gettext as _
from invenio_records import Record
from invenio_records.models import RecordMetadata
from .forms import RecordForm
from .utils import create_record
blueprint = Blueprint(
'invenio_unicorn',
__name__,
template_folder='templates',
static_folder='static',
)
@blueprint.route("/")
def index():
"""Basic view."""
return render_template(
"invenio_unicorn/index.html",
module_name=_('Invenio-Unicorn'))
@blueprint.route('/create', methods=['GET', 'POST'])
def create():
"""The create view."""
form = RecordForm()
# if the form is valid
if form.validate_on_submit():
# create the record
create_record(
dict(
title=form.title.data,
description=form.description.data
)
)
# redirect to the success page
return redirect(url_for('invenio_unicorn.success'))
records = _get_all()
return render_template('invenio_unicorn/create.html', form=form, records=records)
def _get_all():
"""Return all records."""
return [Record(obj.json, model=obj) for obj in RecordMetadata.query.all()]
@blueprint.route("/success")
def success():
"""The success view."""
return render_template('invenio_unicorn/success.html')
3. Create the templates¶
And now, let’s create the templates
in invenio_unicorn/templates/invenio_unicorn/create.html
we override
two blocks
from the invenio BASE_TEMPLATE
and those are:
- javascript
- page_body
In the javascript
block we will right a small fetcher, to get the
created records from the API, and in the page_body
we will add the
form and the placeholder for the records list.
{%- extends config.BASE_TEMPLATE %}
{% macro errors(field) %}
{% if field.errors %}
<span class="help-block">
<ul class=errors>
{% for error in field.errors %}
<li>{{ error }}</li>
{% endfor %}
</ul>
{% endif %}
</span>
{% endmacro %}
{% block page_body %}
<div class="container">
<div class="row">
<div class="col-md-12">
<div class="alert alert-warning">
<b>Heads up!</b> This example is for demo proposes only
</div>
<h2>Create record</h2>
</div>
<div class="col-md-offset-3 col-md-6 well">
<form action="{{ url_for('invenio_unicorn.create') }}" method="POST">
<div class="form-group {{ 'has-error' if form.title.errors }}">
<label for="title">{{ form.title.label }}</label>
{{ form.title(class_="form-control")|safe }}
{{ errors(form.title) }}
</div>
<div class="form-group {{ 'has-error' if form.description.errors }}">
<label for="description">{{ form.description.label }}</label>
{{ form.description(class_="form-control")|safe }}
{{ errors(form.description) }}
</div>
{{ form.csrf_token }}
<button type="submit" class="btn btn-default">Submit</button>
</form>
</div>
</div>
<hr />
<div class="row">
<div class="col-md-12">
{% if records %}
<h2>Records created</h2>
<ol id="custom-records">
{% for record in records %}
<li>{{record.title}}</li>
{% endfor %}
</ol>
{% endif %}
</div>
</div>
</div>
{% endblock page_body %}
in invenio_unicorn/templates/invenio_unicorn/success.html
{%- extends config.BASE_TEMPLATE %}
{% block page_body %}
<div class="container">
<div class="row">
<div class="col-md-12">
<div class="alert alert-success">
<b>Success!</b>
</div>
<a href="{{ url_for('invenio_unicorn.create') }}" class="btn btn-warning">Create more</a>
<hr />
<center>
<iframe src="//giphy.com/embed/WZmgVLMt7mp44" width="480" height="480" frameBorder="0" class="giphy-embed" allowFullScreen></iframe><p><a href="http://giphy.com/gifs/kawaii-colorful-unicorn-WZmgVLMt7mp44">via GIPHY</a></p>
</center>
</div>
</div>
</div>
{% endblock page_body %}
4. Create the record creation function¶
in invenio_unicorn/utils.py
On the utils.py
module will create a helper function that creates a record.
"""Utils module."""
from __future__ import absolute_import, print_function
import uuid
from flask import current_app
from invenio_db import db
from invenio_indexer.api import RecordIndexer
from invenio_pidstore import current_pidstore
from invenio_records.api import Record
def create_record(data):
"""Create a record.
:param dict data: The record data.
"""
indexer = RecordIndexer()
# create uuid
rec_uuid = uuid.uuid4()
# add the schema
host = current_app.config.get('JSONSCHEMAS_HOST')
data["$schema"] = \
current_app.extensions['invenio-jsonschemas'].path_to_url(
'custom_record/custom-record-v1.0.0.json')
# create PID
current_pidstore.minters['custid'](
rec_uuid, data, pid_value='custom_pid_{}'.format(rec_uuid)
)
# create record
created_record = Record.create(data, id_=rec_uuid)
db.session.commit()
# index the record
indexer.index(created_record)
Demo time¶
Let’s start our server again.
vagrant> invenio run -h 0.0.0.0
Then go to http://192.168.50.10/create
and you will see the form we just
created. There are two fields Title
and Description
.
Let’s try the form, add something to the Title
and click submit, you will
see the validation errors on the form, fill in the Description
and click
submit. The form is now valid and it navigates you to the /success
page.