.. This file is part of Invenio. Copyright (C) 2018 CERN. Invenio is free software; you can redistribute it and/or modify it under the terms of the MIT License; see LICENSE file for more details. .. _developing-with-invenio: Developing with Invenio ======================= As described in the previous section :ref:`build-a-module`, Invenio has a modular design. Therefore in order to extend the application, we need to develop new modules. After covering how to create modules with cookiecutter, in this section we will go through the details of the development process. Form, views and templates ------------------------- In this tutorial we'll see how to add data to our Invenio application. To accomplish this we will cover several parts of the development process such as: - How to create a form. - How to create a new view. - How to add a utility function. - How to add new templates. - How to use Jinja2. - How to define your own JSON Schema. 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 Python module that contains the forms of our project, we will use `Flask-WTF `_. In ``invenio_foo/forms.py`` .. code-block:: python """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_foo/views.py`` we'll create the endpoints for - ``create``: Form template - ``success``: Success template and register all the views to our application. .. code-block:: python """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_foo', __name__, template_folder='templates', static_folder='static', ) @blueprint.route("/") def index(): """Basic view.""" return render_template( "invenio_foo/index.html", module_name=_('invenio-foo')) @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_foo.success')) records = _get_all() return render_template('invenio_foo/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_foo/success.html') 3. Create the templates +++++++++++++++++++++++ And now, let's create the templates. We create a ``create.html`` template in ``invenio_foo/templates/invenio_foo/`` where we can override the ``page_body`` block, to place our form: .. code-block:: html {% extends config.FOO_BASE_TEMPLATE %} {% macro errors(field) %} {% if field.errors %}
    {% for error in field.errors %}
  • {{ error }}
  • {% endfor %}
{% endif %} {% endmacro %} {% block page_body %}
Heads up! This example is for demo proposes only

Create record

{{ form.title(class_="form-control")|safe }} {{ errors(form.title) }}
{{ form.description(class_="form-control")|safe }} {{ errors(form.description) }}
{{ form.csrf_token }}

{% if records %}

Records created

    {% for record in records %}
  1. {{record.title}}
  2. {% endfor %}
{% endif %}
{% endblock page_body %} And finally, the ``success.html`` page in `invenio_foo/templates/invenio_foo/` which will be rendered after a record is created. .. code-block:: html {% extends config.FOO_BASE_TEMPLATE %} {% block page_body %} {% endblock page_body %} 4. Write the record creation function +++++++++++++++++++++++++++++++++++++ The ``utils.py`` file contains all helper functions of our module, so let's write the first utility that will create a record. In ``invenio_foo/utils.py`` .. code-block:: python """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 data["$schema"] = \ current_app.extensions['invenio-jsonschemas'].path_to_url( 'records/custom-record-v1.0.0.json' ) # create PID current_pidstore.minters['recid'](rec_uuid, data) # create record created_record = Record.create(data, id_=rec_uuid) db.session.commit() # index the record indexer.index(created_record) 5. Create the custom-record JSON Schema +++++++++++++++++++++++++++++++++++++++ Our records can use a custom schema. To define and use this schema, we create the ``custom-record-v1.0.0.json`` file inside the ``records`` folder of your data model project (``my-datamodel`` from the Quickstart tutorial :ref:`understanding-data-models`). In ``my-datamodel/my-datamodel/jsonschemas/records/custom-record-v1.0.0.json``: .. code-block:: json { "$schema": "http://json-schema.org/draft-04/schema#", "id": "http://localhost/schemas/records/custom-record-v1.0.0.json", "additionalProperties": true, "title": "my-datamodel v1.0.0", "type": "object", "properties": { "title": { "description": "Record title.", "type": "string" }, "description": { "description": "Record description.", "type": "string" }, "id": { "description": "Invenio record identifier (integer).", "type": "string" } }, "required": [ "title", "description" ] } Demo time --------- Let's now see our Invenio module in action after it has been integrated in our Invenio instance. First, install the new invenio-foo module in the virtual enviroment of the Invenio instance: .. code-block:: console $ pipenv shell # activate the app virtual env (my-site) $ cd ../invenio-foo (my-site) $ pip install --editable . Then, if you've followed the steps in the :ref:`quickstart` guide, you can go to the instance folder, `my-site`, and start the ``server`` script: .. code-block:: console (my-site) $ cd ../my-site (my-site) $ ./scripts/server Then go to ``http://localhost:5000/create`` and you will see the form we just created. There are two fields ``Title`` and ``Description``. Let's try the form. Add something in the ``Title`` field and click on submit: you will see a validation error on the form. Fill in the ``Description`` field and click on submit: the form is now valid and it navigates you to the ``/success`` page.