Improve currencies (#604)

- Rename "No Currency" to ISO4217 "XXX"
- Use Babel to render currency symbols and names in currency lists
- Improve i18n in bill lists

Fix #601
Fix #600

ihatemoney/currency_convertor.py

@@ -13,7 +13,7 @@ class Singleton(type):
 
 class CurrencyConverter(object, metaclass=Singleton):
     # Get exchange rates
-    default = "No Currency"
+    no_currency = "XXX"
     api_url = "https://api.exchangeratesapi.io/latest?base=USD"
 
     def __init__(self):
@@ -22,19 +22,23 @@ class CurrencyConverter(object, metaclass=Singleton):
     @cached(cache=TTLCache(maxsize=1, ttl=86400))
     def get_rates(self):
         rates = requests.get(self.api_url).json()["rates"]
-        rates[self.default] = 1.0
+        rates[self.no_currency] = 1.0
         return rates
 
-    def get_currencies(self):
-        rates = [rate for rate in self.get_rates()]
-        rates.sort(key=lambda rate: "" if rate == self.default else rate)
+    def get_currencies(self, with_no_currency=True):
+        rates = [
+            rate
+            for rate in self.get_rates()
+            if with_no_currency or rate != self.no_currency
+        ]
+        rates.sort(key=lambda rate: "" if rate == self.no_currency else rate)
         return rates
 
     def exchange_currency(self, amount, source_currency, dest_currency):
         if (
             source_currency == dest_currency
-            or source_currency == self.default
-            or dest_currency == self.default
+            or source_currency == self.no_currency
+            or dest_currency == self.no_currency
         ):
             return amount
 

ihatemoney/forms.py

@@ -1,4 +1,3 @@
-import copy
 from datetime import datetime
 from re import match
 
@@ -23,7 +22,11 @@ from wtforms.validators import (
 
 from ihatemoney.currency_convertor import CurrencyConverter
 from ihatemoney.models import LoggingMode, Person, Project
-from ihatemoney.utils import eval_arithmetic_expression, slugify
+from ihatemoney.utils import (
+    eval_arithmetic_expression,
+    render_localized_currency,
+    slugify,
+)
 
 
 def strip_filter(string):
@@ -33,18 +36,6 @@ def strip_filter(string):
         return string
 
 
-def get_editprojectform_for(project, **kwargs):
-    """Return an instance of EditProjectForm configured for a particular project.
-    """
-    form = EditProjectForm(**kwargs)
-    choices = copy.copy(form.default_currency.choices)
-    choices.sort(
-        key=lambda rates: "" if rates[0] == project.default_currency else rates[0]
-    )
-    form.default_currency.choices = choices
-    return form
-
-
 def get_billform_for(project, set_default=True, **kwargs):
     """Return an instance of BillForm configured for a particular project.
 
@@ -56,20 +47,15 @@ def get_billform_for(project, set_default=True, **kwargs):
     if form.original_currency.data == "None":
         form.original_currency.data = project.default_currency
 
-    if form.original_currency.data != CurrencyConverter.default:
-        choices = copy.copy(form.original_currency.choices)
-        choices.remove((CurrencyConverter.default, CurrencyConverter.default))
-        choices.sort(
-            key=lambda rates: "" if rates[0] == project.default_currency else rates[0]
-        )
-        form.original_currency.choices = choices
-    else:
-        form.original_currency.render_kw = {"default": True}
-        form.original_currency.data = CurrencyConverter.default
+    show_no_currency = form.original_currency.data == CurrencyConverter.no_currency
+
+    form.original_currency.choices = [
+        (currency_name, render_localized_currency(currency_name, detailed=False))
+        for currency_name in form.currency_helper.get_currencies(
+            with_no_currency=show_no_currency
+        )
+    ]
 
-    form.original_currency.label = Label(
-        "original_currency", "Currency (Default: %s)" % (project.default_currency)
-    )
     active_members = [(m.id, m.name) for m in project.active_members]
 
     form.payed_for.choices = form.payer.choices = active_members
@@ -121,14 +107,14 @@ class EditProjectForm(FlaskForm):
     project_history = BooleanField(_("Enable project history"))
     ip_recording = BooleanField(_("Use IP tracking for project history"))
     currency_helper = CurrencyConverter()
-    default_currency = SelectField(
-        _("Default Currency"),
-        choices=[
-            (currency_name, currency_name)
-            for currency_name in currency_helper.get_currencies()
-        ],
-        validators=[DataRequired()],
-    )
+    default_currency = SelectField(_("Default Currency"), validators=[DataRequired()],)
+
+    def __init__(self, *args, **kwargs):
+        super().__init__(*args, **kwargs)
+        self.default_currency.choices = [
+            (currency_name, render_localized_currency(currency_name, detailed=True))
+            for currency_name in self.currency_helper.get_currencies()
+        ]
 
     @property
     def logging_preference(self):
@@ -242,14 +228,7 @@ class BillForm(FlaskForm):
     payer = SelectField(_("Payer"), validators=[DataRequired()], coerce=int)
     amount = CalculatorStringField(_("Amount paid"), validators=[DataRequired()])
     currency_helper = CurrencyConverter()
-    original_currency = SelectField(
-        _("Currency"),
-        choices=[
-            (currency_name, currency_name)
-            for currency_name in currency_helper.get_currencies()
-        ],
-        validators=[DataRequired()],
-    )
+    original_currency = SelectField(_("Currency"), validators=[DataRequired()],)
     external_link = URLField(
         _("External link"),
         validators=[Optional()],
@@ -281,14 +260,14 @@ class BillForm(FlaskForm):
         bill.external_link = ""
         bill.date = self.date
         bill.owers = [Person.query.get(ower, project) for ower in self.payed_for]
-        bill.original_currency = CurrencyConverter.default
+        bill.original_currency = CurrencyConverter.no_currency
         bill.converted_amount = self.currency_helper.exchange_currency(
             bill.amount, bill.original_currency, project.default_currency
         )
 
         return bill
 
-    def fill(self, bill):
+    def fill(self, bill, project):
         self.payer.data = bill.payer_id
         self.amount.data = bill.amount
         self.what.data = bill.what
@@ -297,6 +276,14 @@ class BillForm(FlaskForm):
         self.date.data = bill.date
         self.payed_for.data = [int(ower.id) for ower in bill.owers]
 
+        self.original_currency.label = Label("original_currency", _("Currency"))
+        self.original_currency.description = _(
+            "Project default: %(currency)s",
+            currency=render_localized_currency(
+                project.default_currency, detailed=False
+            ),
+        )
+
     def set_default(self):
         self.payed_for.data = self.payed_for.default
 

ihatemoney/migrations/versions/927ed575acbd_add_currencies.py

@@ -23,7 +23,7 @@ def upgrade():
         sa.Column(
             "original_currency",
             sa.String(length=3),
-            server_default=CurrencyConverter.default,
+            server_default=CurrencyConverter.no_currency,
             nullable=True,
         ),
     )
@@ -42,7 +42,7 @@ def upgrade():
         sa.Column(
             "default_currency",
             sa.String(length=3),
-            server_default=CurrencyConverter.default,
+            server_default=CurrencyConverter.no_currency,
             nullable=True,
         ),
     )

ihatemoney/run.py

@@ -3,7 +3,7 @@ import os.path
 import warnings
 
 from flask import Flask, g, render_template, request, session
-from flask_babel import Babel
+from flask_babel import Babel, format_currency
 from flask_mail import Mail
 from flask_migrate import Migrate, stamp, upgrade
 from werkzeug.middleware.proxy_fix import ProxyFix
@@ -153,6 +153,22 @@ def create_app(
     # Translations
     babel = Babel(app)
 
+    # Undocumented currencyformat filter from flask_babel is forwarding to Babel format_currency
+    # We overwrite it to remove the currency sign ¤ when there is no currency
+    def currencyformat_nc(number, currency, *args, **kwargs):
+        """
+        Same as flask_babel.Babel.currencyformat, but without the "no currency ¤" sign
+        when there is no currency.
+        """
+        return format_currency(
+            number,
+            currency if currency != CurrencyConverter.no_currency else "",
+            *args,
+            **kwargs
+        ).strip()
+
+    app.jinja_env.filters["currencyformat_nc"] = currencyformat_nc
+
     @babel.localeselector
     def get_locale():
         # get the lang from the session if defined, fallback on the browser "accept

ihatemoney/templates/forms.html

@@ -124,7 +124,7 @@
     {{ input(form.what, inline=True) }}
     {{ input(form.payer, inline=True, class="form-control custom-select") }}
     {{ input(form.amount, inline=True) }}
-    {% if not form.original_currency.render_kw %}
+    {% if g.project.default_currency != "XXX" %}
         {{ input(form.original_currency, inline=True) }}
     {% endif %}
     {{ input(form.external_link, inline=True) }}

ihatemoney/templates/list_bills.html

@@ -1,5 +1,9 @@
 {% extends "sidebar_table_layout.html" %}
 
+{%- macro bill_amount(bill, currency=bill.original_currency, amount=bill.amount) %}
+    {{ amount|currencyformat_nc(currency) }} ({{ _("%(amount)s each", amount=bill.pay_each_default(amount)|currencyformat_nc(currency)) }})
+{% endmacro -%}
+
 {% block title %} - {{ g.project.name }}{% endblock %}
 {% block js %}
     {% if add_bill %} $('#new-bill > a').click(); {% endif %}
@@ -123,11 +127,6 @@
                 </th><th>{{ _("For what?") }}
                 </th><th>{{ _("For whom?") }}
                 </th><th>{{ _("How much?") }}
-                {% if g.project.default_currency != "No Currency" %}
-                  </th><th>{{ _("Amount in %(currency)s", currency=g.project.default_currency) }}
-                {%- else -%}
-                  </th><th>{{ _("Amount") }}
-                {% endif %}
                 </th><th>{{ _("Actions") }}</th></tr>
             </thead>
         <tbody>
@@ -149,13 +148,11 @@
                 {{ bill.owers|join(', ', 'name') }}
                 {%- endif %}</td>
                 <td>
-                    {% if bill.original_currency != "No Currency" %}
-                        {{ "%0.2f"|format(bill.amount) }} {{bill.original_currency}} ({{ "%0.2f"|format(bill.pay_each_default(bill.amount)) }} {{bill.original_currency}} {{ _(" each") }})
-                    {%- else -%}
-                        {{ "%0.2f"|format(bill.amount) }} ({{ "%0.2f"|format(bill.pay_each_default(bill.amount)) }} {{ _(" each") }})
-                    {% endif %}
+                    <span data-toggle="tooltip" data-placement="top"
+                        title="{{ bill_amount(bill, g.project.default_currency, bill.converted_amount) if bill.original_currency != g.project.default_currency else '' }}">
+                        {{ bill_amount(bill) }}
+                    </span>
                 </td>
-                <td>{{ "%0.2f"|format(bill.converted_amount) }}</td>
                 <td class="bill-actions">
                     <a class="edit" href="{{ url_for(".edit_bill", bill_id=bill.id) }}" title="{{ _("edit") }}">{{ _('edit') }}</a>
                     <a class="delete" href="{{ url_for(".delete_bill", bill_id=bill.id) }}" title="{{ _("delete") }}">{{ _('delete') }}</a>

ihatemoney/utils.py

@@ -9,8 +9,9 @@ import os
 import re
 
 from babel import Locale
+from babel.numbers import get_currency_name, get_currency_symbol
 from flask import current_app, redirect, render_template
-from flask_babel import get_locale
+from flask_babel import get_locale, lazy_gettext as _
 import jinja2
 from werkzeug.routing import HTTPException, RoutingException
 
@@ -281,6 +282,20 @@ class FormEnum(Enum):
         return str(self.value)
 
 
+def render_localized_currency(code, detailed=True):
+    if code == "XXX":
+        return _("No Currency")
+    locale = get_locale() or "en_US"
+    symbol = get_currency_symbol(code, locale=locale)
+    details = ""
+    if detailed:
+        details = f" − {get_currency_name(code, locale=locale)}"
+    if symbol == code:
+        return f"{code}{details}"
+    else:
+        return f"{code} − {symbol}{details}"
+
+
 def render_localized_template(template_name_prefix, **context):
     """Like render_template(), but selects the right template according to the
     current user language.  Fallback to English if a template for the

ihatemoney/web.py

@@ -41,6 +41,7 @@ from ihatemoney.currency_convertor import CurrencyConverter
 from ihatemoney.forms import (
     AdminAuthenticationForm,
     AuthenticationForm,
+    EditProjectForm,
     InviteForm,
     MemberForm,
     PasswordReminder,
@@ -48,7 +49,6 @@ from ihatemoney.forms import (
     ResetPasswordForm,
     UploadForm,
     get_billform_for,
-    get_editprojectform_for,
 )
 from ihatemoney.history import get_history, get_history_queries
 from ihatemoney.models import Bill, LoggingMode, Person, Project, db
@@ -377,7 +377,7 @@ def reset_password():
 
 @main.route("/<project_id>/edit", methods=["GET", "POST"])
 def edit_project():
-    edit_form = get_editprojectform_for(g.project)
+    edit_form = EditProjectForm()
     import_form = UploadForm()
     # Import form
     if import_form.validate_on_submit():
@@ -393,10 +393,10 @@ def edit_project():
     if edit_form.validate_on_submit():
         project = edit_form.update(g.project)
         # Update converted currency
-        if project.default_currency != CurrencyConverter.default:
+        if project.default_currency != CurrencyConverter.no_currency:
             for bill in project.get_bills():
 
-                if bill.original_currency == CurrencyConverter.default:
+                if bill.original_currency == CurrencyConverter.no_currency:
                     bill.original_currency = project.default_currency
 
                 bill.converted_amount = CurrencyConverter().exchange_currency(
@@ -417,6 +417,7 @@ def edit_project():
                 edit_form.ip_recording.data = True
 
         edit_form.contact_email.data = g.project.contact_email
+        edit_form.default_currency.data = g.project.default_currency
 
     return render_template(
         "edit_project.html",
@@ -732,7 +733,7 @@ def edit_bill(bill_id):
         return redirect(url_for(".list_bills"))
 
     if not form.errors:
-        form.fill(bill)
+        form.fill(bill, g.project)
 
     return render_template("add_bill.html", form=form, edit=True)