diff -r 52bf52e6fc77 -r 1091d8d63f51 doc/book/en/01-introduction.en.txt --- a/doc/book/en/01-introduction.en.txt Thu Nov 20 10:25:44 2008 -0800 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -1,335 +0,0 @@ -.. -*- coding: utf-8 -*- - -.. _Overview: - -Quick overview of `CubicWeb` -============================ - -`CubicWeb` allows us to develop web applications instances based on -one or more `cubes`. - -What we call a `cube` is a model defining the data types and views. -A `cube` is a reusable component grouped with others cubes in the file -system. - -An `instance` refers to a specific installation of one or more `cubes` - where are grouped configuration files of the final web application. - -In this document, we will show you how to create a `cube` and how to use it -in an `instance` for your web application. - -Create your cube ----------------- - -After you installed your `CubicWeb` development environment, you can start -to build your first cube: :: - - cubicweb-ctl newcube blog - -This will create in ``/path/to/forest/cubes`` a directory containing: :: - - blog/ - | - |-- data/ - | |-- cubes.blog.css - | |-- cubes.blog.js - | |-- external_resources - | - |-- debian/ - | |-- changelog - | |-- compat - | |-- control - | |-- copyright - | |-- cubicweb-blog.prerm - | |-- rules - | - |-- entities.py - | - |-- i18n/ - | |-- en.po - | |-- fr.po - | - |-- __init__.py - | - |-- MANIFEST.in - | - |-- migration/ - | |-- postcreate.py - | |-- precreate.py - | - |-- __pkginfo__.py - | - |-- schema.py - | - |-- setup.py - | - |-- site_cubicweb.py - | - |-- sobjects.py - | - |-- test/ - | |-- data/ - | |-- bootstrap_cubes - | |-- pytestconf.py - | |-- realdb_test_blog.py - | |-- test_blog.py - | - |-- views.py - -Any changes applied to your data model should be done in this -directory. - - -Define your data schema ------------------------ - -The data model or schema is hte core of your `CubicWeb` application. -This is where is defined the type of content you application will handle. - -The data model is defined in the file ``schema.py`` of your cube -``blog`` such as follows. - -:: - - from cubicweb.schema import format_constraint - class Blog(EntityType): - title = String(maxsize=50, required=True) - description = String() - - class BlogEntry(EntityType): - title = String(required=True, fulltextindexed=True, maxsize=256) - publish_date = Date(default='TODAY') - content = String(required=True, fulltextindexed=True) - entry_of = SubjectRelation('Blog', cardinality='?*') - - -A Blog has a title and a description. The title is a string that is -required by the class EntityType and must be less than 50 characters. -The description is a string that is not constrained. - -A BlogEntry has a title, a publish_date and a content. The title is a -string that is required and must be less than 100 characters. The -publish_date is a Date with a default value of TODAY, meaning that -when a BlogEntry is created, its publish_date will be the current day -unless it is modified. The content is a string that will be indexed in -the full-text index and has no constraint. - -A BlogEntry also has a relationship ``entry_of`` that links it to a -Blog. The cardinality ``?*`` means that a BlogEntry can be part of -zero or one Blog (``?`` means `zero or one`) and that a Blog can -have any number of BlogEntry (``*`` means `any number including -zero`). For completeness, remember that ``+`` means `one or more`. - - -Create your instance --------------------- - -:: - - cubicweb-ctl create blog blogdemo - - -This command will create a directory ``~/etc/cubicweb.d/blogdemo`` -which will contain all the configuration files required to start -you web application. - -The instance ``blogdemo`` is based on the cube ``blog``. - - -Welcome in your web application -------------------------------- - -Run your application with the following command: :: - - cubicweb-ctl start -D blogdemo - - -You can now access to your web application to create blogs and post messages -by visitin the URL http://localhost:8080/. -A login form will first be prompted. By default, the application will not allow -anonymous user to get in the application. You should then use the admin -account you created at the time you initialized the database with -``cubicweb-ctl create``. - -.. image:: images/login-form.png - - -Once authenticated, you can start playing with your application -and create entities. Bravo! - -.. image:: images/blog-demo-first-page.png - -Please notice that so far, `CubicWeb` franework managed all aspects of -the web application based in the schema provided at first. - - -Create entities ---------------- - -We will now create a couple of entities in our web application. - -Create a Blog -~~~~~~~~~~~~~ - -Let us create a few of these entities. Click on the `[+]` at the right -of the link Blog. Call this new Blog ``Tech-blog`` and type in -``everything about technology`` as the description, then validate the -form by clicking on ``Validate``. - -.. image:: images/cbw-create-blog.en.png - :alt: from to create blog - -Click on the logo at top left to get back to the home page, then -follow the Blog link that will list for you all the existing Blog. -You should be seeing a list with a single item ``Tech-blog`` you -just created. - -.. image:: images/cbw-list-one-blog.en.png - :alt: displaying a list of a single blog - -Clicking on this item will get you to its detailed description except -that in this case, there is not much to display besides the name and -the phrase ``everything about technology``. - -Now get back to the home page by clicking on the top-left logo, then -create a new Blog called ``MyLife`` and get back to the home page -again to follow the Blog link for the second time. The list now -has two items. - -.. image:: images/cbw-list-two-blog.en.png - :alt: displaying a list of two blogs - -Create a BlogEntry -~~~~~~~~~~~~~~~~~~ - -Get back to the home page and click on [+] at the right of the link -BlogEntry. Call this new entry ``Hello World`` and type in some text -before clicking on ``Validate``. You added a new blog entry without -saying to what blog it belongs. There is a box on the left entitled -``actions``, click on the menu item ``modify``. You are back to the form -to edit the blog entry you just created, except that the form now has -another section with a combobox titled ``add relation``. Chose -``entry_of`` in this menu and a second combobox appears where you pick -``MyLife``. - -You could also have, at the time you started to fill the form for a -new entity BlogEntry, hit ``Apply`` instead of ``Validate`` and the -combobox titled ``add relation`` would have showed up. - - -.. image:: images/cbw-add-relation-entryof.en.png - :alt: editing a blog entry to add a relation to a blog - -Validate the changes by clicking ``Validate``. The entity BlogEntry -that is displayed now includes a link to the entity Blog named -``MyLife``. - -.. image:: images/cbw-detail-one-blogentry.en.png - :alt: displaying the detailed view of a blogentry - -Please notice that so far, `CubicWeb` franework managed all aspects of -the web application based in the schema provided at first. -Also if you wish to get a graphical view of the schema, visit -the link `Application schema`` which will direct you to : -http://localhost:8080/view?vid=schema - -.. image:: images/cbw-schema.en.png - :alt: graphical view of the schema (aka data-model) - - -Define your entities views --------------------------- - -The views selection principle -~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ - -A view is defined by a Python class which includes: - - - an identifier (all objects in `CubicWeb` are entered in a registry - and this identifier will be used as a key) - - - a filter to select the resulsets it can be applied to - - -`CubicWeb` provides a lot of standard views for the type -`EntityView`, for a complete list, you -will have to read the code in directory ``cubicweb/web/views/`` - -A view is applied on a `result set` which contains a set of -entities we are trying to display. `CubicWeb` uses a selector -mecanism which computes a score used to identify which view -is the best to apply for the `result set` we are trying to -display. The standard library of selectors is in -``cubicweb.common.selector`` and a library of methods used to -compute scores is available in ``cubicweb.vregistry.vreq``. - -It is possible to define multiple views for the same identifier -and to associate selectors and filters to allow the application -to find the best way to render the data. We will see more details -on this in :ref:`DefinitionVues`. - -For example, the view named ``primary`` is the one used to display -a single entity. We will now show you hos to customize this view. - - -View customization -~~~~~~~~~~~~~~~~~~ - -If you wish to modify the way a `BlogEntry` is rendered, you will have to -overwrite the `primary` view defined in the module ``views`` of the cube -``cubes/blog/views.py``. - -We can by example add in front of the pulication date a prefix specifying -the date we see is the publication date. - -To do so, please apply the following changes: - -:: - - from cubicweb.web.views import baseviews - - - class BlogEntryPrimaryView(baseviews.PrimaryView): - - accepts = ('BlogEntry',) - - def render_entity_title(self, entity): - self.w(u'
published on %s
' % entity.publish_date.strftime('%Y-%m-%d')) - self.w(u'%s
' % entity.content) - - # display relations - siderelations = [] - if self.main_related_section: - self.render_entity_relations(entity, siderelations) - -.. note:: - When a view is modified, it is not required to restart the application - server. Save the Python file and reload the page in your web browser - to view the changes. - -You can now see that the publication date has a prefix. - -.. image:: images/cbw-update-primary-view.en.png - :alt: modified primary view - - -The above source code defines a new primary view for -``BlogEntry``. - -Since views are applied to resultsets and resulsets can be tables of -data, it is needed to recover the entity from its (row,col) -coordinates. We will get to this in more detail later. - -The view has a ``self.w()`` method that is used to output data. In our -example we use it to output HTML tags and values of the entity's attributes. -