;;;; blog-v3: Widgets
;;;;
;;;; Now let's make some widgets to show and edit the blog. The
;;;; simplest widget that we can probably make is to just present some
;;;; data using a data view. We specialize on RENDER-WIDGET-BODY to
;;;; render the widget.
;;; src/widgets/post.lisp
(in-package :blog)
(defwidget post-widget ()
((post :accessor post
:initarg :post
:initform nil)
(mode :accessor mode
:initarg :mode
:initform :short
:documentation "The post can be displayed in two
versions, :SHORT and :FULL.")
(short-view :accessor short-view
:initarg :short-view
:initform nil
:documentation "View to determine how the post is
displayed when in :SHORT mode.")
(full-view :accessor full-view
:initarg :full-view
:initform nil
:documentation "View to determine how the post is
displayed when in :SHORT mode."))
(:documentation "widget to handle a blog post"))
(defmethod render-widget-body ((obj post-widget) &key)
(ecase (mode obj)
(:short
(when (short-view obj)
(render-object-view (post obj) (short-view obj) :widget obj)))
(:full
(when (full-view obj)
(render-object-view (post obj) (full-view obj) :widget obj)))))
;;;; In the top of the admin page let's add a link that will display
;;;; the blog. For now, we'll have the function MAKE-BLOG-WIDGET just
;;;; return a composite widget with a POST-WIDGET inside, and we'll
;;;; later put a BLOG-WIDGET instead. Since we just want to check
;;;; that our home-made widget displays correctly, let's initialize it
;;;; with the POST that has ID=1 (create a post with the admin page).
;;;;
;;;; Note that I don't fully understand the continuation framework
;;;; yet, so I used DO-PAGE and ANSWER by trial and error and the
;;;; calls below work but I don't know if it's the best way to do
;;;; this.
;;; src/layout.lisp
(in-package :blog)
(defun make-users-gridedit ()
(make-instance 'gridedit
:name 'users-grid
:data-class 'user
:view 'user-table-view
:widget-prefix-fn (lambda (&rest args)
(declare (ignore args))
(with-html (:h1 "Users")))
:item-data-view 'user-data-view
:item-form-view 'user-form-view))
(defun make-posts-gridedit ()
(make-instance 'gridedit
:name 'posts-grid
:data-class 'post
:widget-prefix-fn (lambda (&rest args)
(declare (ignore args))
(with-html (:h1 "Posts")))
:view 'post-table-view
:item-data-view 'post-data-view
:item-form-view 'post-form-view))
(defun make-admin-page ()
(make-instance 'composite
:widgets
(list (lambda ()
(render-link (lambda (&rest args)
(declare (ignore args))
(do-page (make-blog-widget)))
"view blog"))
(make-users-gridedit)
(lambda ()
;; gridedit widgets were probably not
;; intended to be put 2 on the same page, so
;; I add an HR tag between the two
(with-html (:div (:hr :style "margin: 2em;"))))
(make-posts-gridedit))))
(defun make-blog-widget ()
(let ((composite
(make-instance
'composite
:widgets (list
(make-instance 'post-widget
:short-view 'post-data-view
:full-view 'post-data-view
:post (post-by-id 0))))))
(push (lambda ()
(render-link (lambda (&rest args)
(declare (ignore args))
(answer composite))
"admin"))
(composite-widgets composite))
composite))
;;; added in src/models.lisp
(defun all-posts (&rest args)
"return all objects of class POST. ARGS is an added argument that is
ignored (needed for use in dropdown lists in views)."
(declare (ignore args))
(find-persistent-objects (class-store 'post) 'post))
(defun post-by-id (id)
(first
(remove-if-not
(lambda (post)
(when (slot-boundp post 'id)
(= id (slot-value post 'id))))
(all-posts))))
;;;; Now you can go and check that the first post is indeed displayed
;;;; (you will need to restart your session or restart the blog
;;;; application), and so let's turn on to making a more useful
;;;; BLOG-WIDGET.
;;;; ChangeLog
blog-v3
* blog.asd (blog): updated for new files
* src/layout.lisp (make-blog-widget): create a composite widget
with a post widget and a link
(make-admin-page): add a link to MAKE-BLOG-WIDGET
* src/models.lisp (all-posts, post-by-id): backend functions
* src/widgets/post.lisp (post-widget): simple post widget
(render-widget-body): specialized method to render the post
blog-v2
* src/models.lisp (post-author-id, all-users): functions used by
the views
* src/views.lisp (post-form-view): override some fields - textarea
for the texts, and dropdown list for the author
blog-v1:
* src/views.lisp (user-table-view, user-data-view, user-form-view)
(post-table-view, post-data-view, post-form-view): scaffolded views
for the gridedit interface
* src/init-session.lisp (init-user-session): call MAKE-ADMIN-PAGE
* src/layout.lisp (make-users-gridedit, make-posts-gridedit)
(make-admin-page): add simple gridedit interface for the two
models
* src/models.lisp (user, post): USER and POST models
) is private.
