Add page to create QR codes

This can be done via the Admin interface but this latter shall be
restricted to admin users. This simple page allows the group "create"
to easily add new Manufacturer, Model or Location.

app/main/forms.py

+# -*- coding: utf-8 -*-
+"""
+app.main.forms
+~~~~~~~~~~~~~~
+
+This module defines the main forms.
+
+:copyright: (c) 2017 European Spallation Source ERIC
+:license: BSD 2-Clause, see LICENSE for more details.
+
+"""
+from flask_wtf import FlaskForm
+from wtforms import SelectField, StringField, validators
+from .. import utils
+
+
+class QRCodeForm(FlaskForm):
+    kind = SelectField('Kind')
+    name = StringField('name', validators=[validators.DataRequired()])
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.kind.choices = utils.get_choices(
+            ('Manufacturer', 'Model', 'Location')
+        )

app/main/views.py

@@ -9,10 +9,14 @@ This module implements the main blueprint.
 :license: BSD 2-Clause, see LICENSE for more details.
 
 """
-from flask import Blueprint, render_template, jsonify
+import sqlalchemy as sa
+from flask import (Blueprint, render_template, jsonify,
+                   redirect, url_for, request, flash)
 from flask_login import login_required
+from .forms import QRCodeForm
 from ..extensions import db
 from ..models import Action, Manufacturer, Model, Location, Status, Item
+from ..decorators import login_groups_accepted
 from .. import utils
 
 bp = Blueprint('main', __name__)
@@ -70,3 +74,33 @@ def qrcodes():
                   for item in items]
         codes[model.__name__] = images
     return render_template('qrcodes.html', codes=codes)
+
+
+@bp.route('/qrcodes/create', methods=('GET', 'POST'))
+@login_groups_accepted('admin', 'create')
+def create_qrcodes():
+    kind = request.args.get('kind', 'Manufacturer')
+    form = QRCodeForm(request.form, kind=kind)
+    if form.validate_on_submit():
+        model = globals()[form.kind.data]
+        new_model = model(name=form.name.data)
+        db.session.add(new_model)
+        try:
+            db.session.commit()
+        except sa.exc.IntegrityError as e:
+            db.session.rollback()
+            flash(f'{form.name.data} already exists! Item not created.', 'error')
+        return redirect(url_for('main.create_qrcodes', kind=form.kind.data))
+    return render_template('create_qrcodes.html', form=form)
+
+
+@bp.route('/_retrieve_qrcodes_name/<kind>')
+@login_required
+def retrieve_qrcodes_name(kind):
+    try:
+        model = globals()[kind]
+    except KeyError:
+        raise utils.InventoryError(f"Unknown model '{kind}'", status_code=422)
+    items = db.session.query(model).order_by(model.name)
+    data = [[item.name] for item in items]
+    return jsonify(data=data)

app/static/js/qrcodes.js

+$(document).ready(function() {
+
+  var qrcodes_table =  $("#qrcodes_table").DataTable({
+    "ajax": function(data, callback, settings) {
+      var kind = $("#kind").val();
+      $.getJSON(
+        $SCRIPT_ROOT + "/_retrieve_qrcodes_name/" + kind,
+        function(json) {
+          callback(json);
+        });
+    },
+    "paging": false
+  });
+
+  $("#kind").on('change', function() {
+    qrcodes_table.ajax.reload();
+  });
+
+});

app/templates/_helpers.html

-{% macro nav_a(active) -%}
-<a class="nav-item nav-link{% if active %} active{% endif %}"
+{% macro is_active(active) -%}
+{% if active %}active{% endif %}
 {%- endmacro %}

app/templates/base.html

 {%- extends "bootstrap/base.html" %}
 {% import "bootstrap/utils.html" as utils %}
-{% from "_helpers.html" import nav_a %}
+{% from "_helpers.html" import is_active %}
 
 {% block styles %}
   {{super()}}
@@ -23,15 +23,23 @@
       <div class="collapse navbar-collapse" id="navbarSupportedContent">
         <div class="navbar-nav mr-auto">
           {% set path = request.path %}
-          {{ nav_a(path in ("/", "/index", "/index/")) }} href="{{ url_for('main.index') }}">Index</a>
-	        {{ nav_a(path == "/qrcodes") }} href="{{ url_for('main.qrcodes') }}">QR Codes</a>
+          <a class="nav-item nav-link {{ is_active(path in ("/", "/index", "/index/")) }}" href="{{ url_for('main.index') }}">Index</a>
+          <div class="dropdown {{ is_active(path.startswith("/qrcodes")) }}">
+            <a class="nav-link dropdown-toggle" href="#" id="qrcodesDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
+              QR Codes
+            </a>
+            <div class="dropdown-menu" aria-labelledby="qrcodesDropdownMenuLink">
+              <a class="dropdown-item" href="{{ url_for('main.qrcodes') }}">View</a>
+              <a class="dropdown-item" href="{{ url_for('main.create_qrcodes') }}">Create</a>
+            </div>
+          </div>
           {% if current_user.is_authenticated and current_user.is_admin %}
             <a class="nav-item nav-link" href="{{ url_for('admin.index') }}">Admin</a>
           {% endif %}
         </div>
         <div class="navbar-nav">
           {% if current_user.is_authenticated %}
-          <div class="dropdown">
+          <div class="dropdown {{ is_active(path == "/profile") }}">
             <a class="nav-link dropdown-toggle" href="#" id="navbarDropdownMenuLink" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
               {{current_user}}
             </a>

app/templates/create_qrcodes.html

+{%- extends "base.html" %}
+{% import "bootstrap/wtf.html" as wtf %}
+
+{% block title %}Create QR Codes{% endblock %}
+
+{% block main %}
+  <h2>Create QR Codes</h2>
+
+  <form method="POST" class="form-inline">
+    {{ form.csrf_token }}
+
+    {{ form.kind.label(class="sr-only") | safe }}
+    {{ form.kind(class="form-control mb-2 mr-sm-2 mb-sm-0") }}
+
+    {{ form.name.label(class="sr-only") | safe }}
+    {{ form.name(class="form-control mb-2 mr-sm-2 mb-sm-0", placeholder="name", required=True) }}
+
+    <button type="submit" class="btn btn-primary">Create</button>
+  </form>
+
+  <hr class="separator">
+
+  <table id="qrcodes_table" class="table table-bordered table-hover table-sm">
+    <thead>
+      <tr>
+        <th>Name</th>
+      </tr>
+    </thead>
+  </table>
+{%- endblock %}
+
+{% block inventory_scripts %}
+  <script src="{{ url_for('static', filename='js/qrcodes.js') }}"></script>
+{% endblock %}

app/utils.py

@@ -92,3 +92,14 @@ def attribute_to_string(value):
         return value[0]
     else:
         return value
+
+
+def get_choices(iterable, allow_blank=False, allow_null=False):
+    """Return a list of (value, label)"""
+    choices = []
+    if allow_blank:
+        choices = [('', '')]
+    if allow_null:
+        choices.append(('null', 'not set'))
+    choices.extend([(val, val) for val in iterable])
+    return choices