Angular docs - code theory and translation

Updates to the angularjs.rst documentation which describe how
Angular code is organized within Horizon framework and the
Dashboard application.

Also updates the documentation for translation to follow the current
patterns.

This completes the dashboard re-organization work planned for https://launchpad.net/bugs/1478717.

View formatted output by:
1. cd /horizon/doc/
2. make html
3. open file:///<path to horizon>/doc/build/html/topics/angularjs.html

Change-Id: Icf892223af01211ad4f764708f925d0a94035f51
Co-Authored-By: Tyr Johanson <tyr@hp.com>
Co-Authored-By: Rob Cresswell <rcresswe@cisco.com>
Partially-Implements: blueprint angular-docs
Closes-Bug: 1478717
This commit is contained in:
Tyr Johanson 2015-07-20 17:35:59 -06:00 committed by Rob Cresswell
parent 6dffd85f97
commit 319b370aa3

View File

@ -46,11 +46,85 @@ local tests. An explanation of the options, and details of others you may want
to use, can be found in the
`ESLint user guide <http://eslint.org/docs/user-guide/configuring>`_.
Application Structure
=====================
OpenStack Dashboard is an example of a Horizon-based Angular application. Other
applications built on the Horizon framework can follow a similar structure. It
is composed of two key Angular modules:
**app.module.js** - The root of the application. Defines the modules required by
the application, and includes modules from its pluggable dashboards.
**framework.module.js** - Reusable Horizon components. It is one of the
application dependencies.
.. _js_file_structure:
File Structure
==============
Horizon has three kinds of angular code:
1. Specific to one dashboard in the OpenStack Dashboard application
2. Specific to the OpenStack Dashboard application, but reusable by multiple
dashboards
3. Reusable by any application based on the Horizon framework
When adding code to horizon, consider whether it is dashboard-specific or should be
broken out as a reusable utility or widget.
Code specific to one dashboard
------------------------------
Code that isn't shared beyond a single dashboard is placed in
``openstack_dashboard/dashboards/mydashboard/static``. Entire dashboards may be
enabled or disabled using Horizon's plugin mechanism. Therefore no dashboards
other than ``mydashboard`` can safely use this code.
The ``openstack_dashboard/dashboards/static`` directory structure determines
how the code is deployed and matches the module structure.
For example:
::
openstack_dashboard/dashboards/identity/static/dashboard/identity/
├── identity.module.js
├── identity.module.spec.js
└── identity.scss
Because the code is in ``openstack_dashboard/dashboards/identity`` we know it
is specific to just the ``identity`` dashboard and not used by any others.
Code shared by multiple dashboards
----------------------------------
Views or utilities needed by multiple dashboards are placed in
``openstack_dashboard/static/app``. For example:
::
openstack_dashboard/static/app/core/cloud-services/
├── cloud-services.js
└── cloud-services.spec.js
The ``cloud-services`` module is used by panels in multiple dashboards. It
cannot be placed within ``openstack_dashboard/dashboards/mydashboard`` because
disabling that one dashboard would break others. Therefore, it is included as
part of the application ``core`` module. Code in ``app/`` is guaranteed to
always be present, even if all other dashboards are disabled.
Reusable components
-------------------
Finally, components that are easily reused by any application are placed in
``horizon/static/framework/``. These do not contain URLs or business logic
that is specific to any application (even the OpenStack Dashboard application).
The modal directive ``horizon/static/framework/widgets/modal/`` is a good
example of a reusable component.
One folder per component
------------------------
Each component should have its own folder, with the code broken up into one JS
component per file. (See `Single Responsibility <https://github.com/johnpapa/angular-styleguide#single-responsibility>`_
in the style guide).
@ -58,36 +132,84 @@ Each folder may include styling (``.scss``), as well as templates(``.html``)
and tests (``.spec.js``).
You may also include examples, by appending ``.example``.
Reusable components are in ``horizon/static/framework/``. These are a
collection of pieces, such as modals or wizards where the functionality
is likely to be used across many parts of horizon.
When adding code to horizon, consider whether it is panel-specific or should be
broken out as a reusable utility or widget.
The modal directive is a good example of the file structure. This is a reusable
component:
::
horizon/static/framework/widgets/modal/
├── modal.controller.js
├── modal.module.js
├── modal.service.js
├── modal.spec.js
└── simple-modal.html
Panel-specific code is in ``openstack_dashboard/static/dashboard/``. For example:
::
openstack_dashboard/static/dashboard/workflow/
├── decorator.service.js
├── workflow.module.js
├── workflow.module.spec.js
└── workflow.service.js
For larger components, such as workflows with multiple steps, consider breaking
the code down further. The Angular **Launch Instance** workflow,
for example, has one directory per step
(``openstack_dashboard/static/dashboard/launch-instance/``)
the code down further. For example, the Launch Instance workflow, has one
directory per step. See
``openstack_dashboard/dashboards/project/static/dashboard/project/workflow/launch-instance/``
SCSS files
----------
The top-level SCSS file in ``openstack_dashboard/static/app/app.scss``. It
includes any styling that is part of the application ``core`` and may be
reused by multiple dashboards. SCSS files that are specific to a particular
dashboard are linked to the application by adding them in that dashboard's
enabled file. For example, `_1000_project.py` is the enabled file for the
``Project`` dashboard and includes:
::
ADD_SCSS_FILES = [
'dashboard/project/project.scss',
]
Styling files are hierarchical, and include any direct child SCSS files. For
example, ``project.scss`` includes the ``workflow`` SCSS file, which in turn
includes any launch instance styling:
::
@import "workflow/workflow";
This allows the application to easily include all needed styling, simply by
including a dashboards top-level SCSS file.
Module Structure
================
Horizon Angular modules use names that map to the source code directory structure.
This provides namespace isolation for modules and services, which makes
dependency injection clearer. It also reduces code conflicts where two
different modules define a module, service or constant of the same name. For
example:
::
openstack_dashboard/dashboards/identity/static/dashboard/identity/
└── identity.module.js
The preferred Angular module name in this example is
``horizon.dashboard.identity``. The ``horizon`` part of the module name maps to
the ``static`` directory and indicates this is a ``horizon`` based application.
``dashboard.identity`` maps to folders that are created within ``static``. This
allows a direct mapping between the angular module name of
``horizon.dashboard.identity`` and the source code directory of
``static\dashboard\identity``.
Services and constants within these modules should all start with their module
name to avoid dependency injection collisions. For example:
::
$provide.constant('horizon.dashboard.identity.basePath', path);
Directives do not require the module name but are encouraged to begin with the
``hz`` prefix. For example:
::
.directive('hzMagicSearchBar', hzMagicSearchBar);
Finally, each module lists its child modules as a dependency. This allows the
root module to be included by an application, which will automatically define
all child modules. For example:
::
.module('horizon.framework', [
'horizon.framework.conf',
'horizon.framework.util',
'horizon.framework.widgets'
])
``horizon.framework`` declares a dependency on ``horizon.framework.widgets``,
which declares dependencies on each individual widget. This allows the
application to access any widget, simply by depending on the top-level
``horizon.framework`` module.
Testing
=======
@ -103,26 +225,48 @@ For more detailed information, see :doc:`javascript_testing`.
Translation (Internationalization and Localization)
===================================================
.. Note::
This is likely to change soon, after the
`Angular Translation <https://blueprints.launchpad.net/horizon/+spec/angular-translate-makemessages>`_
blueprint has been completed.
Translations are handled in Transifex, as with Django. They are merged daily
with the horizon upstream codebase. See
`Translations <https://wiki.openstack.org/wiki/Translations>`_ in the
OpenStack wiki to learn more about this process.
Use either ``gettext`` (singular) or ``ngettext`` (plural):
To translate text in HTML files, you may use the ``translate`` directive or
filter. The directive be used as an element, or an attribute:
::
gettext('text to be translated');
ngettext('text to be translated');
// Translate singular, as element
<translate>Lorem ipsum</translate>
// Translate singular, as attribute
<h1 translate>Lorem ipsum</h1>
// Translate plural (attribute only)
<div translate translate-n="count" translate-plural="apples">apple</div>
// Filter singular
<input type="text" placeholder="{$ 'Username' | translate $}" />
// Comments for translators, to add context
<h1 translate-comment="Verb" translate>File</h1>
.. Note::
The filter does not support plural strings.
To translate text in JS files, such as Angular controllers, use either
``gettext`` (singular) or ``ngettext`` (plural):
::
gettext('apple');
ngettext('apple', 'apples', count);
The :ref:`translatability` section contains information about the
pseudo translation tool, and how to make sure your translations are working
locally.
Horizon uses the `angular-gettext <https://angular-gettext.rocketeer.be>`_
library to provide directives and filters for extracting translatable text.
Creating your own panel
=======================