hsx/src/element.lisp
2024-06-05 08:22:14 +09:00

137 lines
4.1 KiB
Common Lisp

(defpackage #:hsx/element
(:use #:cl)
(:import-from #:hsx/escaper
#:escape-html-attribute
#:escape-html-text-content)
(:import-from #:hsx/group
#:self-closing-tag-p
#:non-escaping-tag-p)
(:export #:element
#:tag
#:html-tag
#:fragment
#:component
#:create-element
#:element-type
#:element-props
#:element-children
#:expand-component
#:render-to-string))
(in-package #:hsx/element)
;;;; class definitions
(defclass element ()
((type
:reader element-type
:initarg :type)
(props
:reader element-props
:initarg :props)
(children
:reader element-children
:initarg :children)))
(defclass tag (element) ())
(defclass html-tag (tag) ())
(defclass fragment (tag) ())
(defclass component (element) ())
;;;; factory
(defun create-element (type props children)
(make-instance
(cond ((functionp type) 'component)
((eq type :<>) 'fragment)
((eq type :html) 'html-tag)
((keywordp type) 'tag)
(t (error "element-type must be a keyword or a function.")))
:type type
:props props
:children (flatten children)))
(defun flatten (x)
(labels ((rec (x acc)
(cond ((null x) acc)
((atom x) (cons x acc))
(t (rec
(car x)
(rec (cdr x) acc))))))
(rec x nil)))
;;;; methods
(defmethod render-to-string ((element element) &key pretty)
(with-output-to-string (stream)
(write element :stream stream :pretty pretty)))
(defmethod print-object ((element tag) stream)
(with-accessors ((type element-type)
(props element-props)
(children element-children)) element
(let ((type-str (string-downcase type)))
(if children
(format stream
(if (and (null (rest children))
(typep (first children) 'string))
"~@<<~a~a>~2I~:_~<~a~^~:@_~:>~0I~_</~a>~:>"
"~@<<~a~a>~2I~:@_~<~@{~a~^~:@_~}~:>~0I~:@_</~a>~:>")
type-str
(props->string props)
(mapcar (lambda (child)
(if (and (not (non-escaping-tag-p type))
(stringp child))
(escape-html-text-content child)
child))
children)
type-str)
(format stream
(if (self-closing-tag-p type)
"<~a~a>"
"<~a~a></~a>")
type-str
(props->string props)
type-str)))))
(defun props->string (props)
(with-output-to-string (stream)
(loop
:for (key value) :on props :by #'cddr
:do (let ((key-str (string-downcase key)))
(if (typep value 'boolean)
(format stream
"~@[ ~a~]"
(and value key-str))
(format stream
" ~a=\"~a\""
key-str
(escape-html-attribute value)))))))
(defmethod print-object ((element html-tag) stream)
(format stream "<!DOCTYPE html>~%")
(call-next-method))
(defmethod print-object ((element fragment) stream)
(with-accessors ((children element-children)) element
(if children
(format stream
(if (rest children)
"~<~@{~a~^~:@_~}~:>"
"~<~a~:>")
children))))
(defmethod print-object ((element component) stream)
(print-object (expand-component element) stream))
(defmethod expand-component ((element component))
(with-accessors ((type element-type)
(props element-props)
(children element-children)) element
(apply type (merge-children-into-props props children))))
(defun merge-children-into-props (props children)
(append props
(and children
(list :children children))))