helm demo 02

elisp-helm-demo-02.el

;;; elisp-helm-demo-02.el --- Write helm extensions demo 02

;; Demo 01 --- with matched got highlighted with `helm-build-in-buffer-source'
(setq a-helm-source
      (helm-build-in-buffer-source "*a helm source*"
        :init (lambda ()
                (let ((text (buffer-string)))
                  (with-current-buffer (helm-candidate-buffer 'global)
                    (insert text))))
        :real-to-display (lambda (cand) (upcase cand)) ; Real displayed stuff
        :action 'message))

(helm :sources '(a-helm-source))


;;; Demo 02 --- use `candidate-transformer'
(setq b-helm-source
      '((name . "B helm source*")
        (candidates . (lambda () (number-sequence 1 100)))
        ;; remove even numbers from candidates
        (candidate-transformer . (lambda (candidates)
                                   (seq-remove 'evenp candidates)))
        (action . message)))

(helm :sources '(b-helm-source))


;;; Demo 03 --- use `filtered-candidate-transformer'
(setq c-helm-source
      '((name . "C helm sourcee")
        (candidates . (lambda () (number-sequence 1 100)))
        (filtered-candidate-transformer .
                                        (lambda (candidates source)
                                          (mapcar (lambda (x)
                                                    (+ (* x 10)
                                                       (string-to-number
                                                        helm-pattern)))
                                                  candidates)))
        (action . message)))

(helm :sources '(c-helm-source))


;;; Demo 04 --- use `display-to-real'
(setq d-helm-source
      '((name . "D helm source")
        (candidates . ;; (("one" . "1") ("two" . "2"))
                    ("one" "two" "three")
                    )
        (display-to-real . (lambda (sel-candidate) (concat ">|< " sel-candidate)))
        (action . message)))

(helm :sources '(d-helm-source))

;;; Demo 06 --- `real-to-display'
(setq f-helm-source
      '((name . "F helm source")
        (candidates . ("one" "two"))
        (real-to-display . (lambda (sel-candidate)
                             (concat "<|> " sel-candidate)))
        (action . message)))

(helm :sources '(f-helm-source))

;;; Demo 05 --- use `filtered-one-by-one'
;; (setq e-helm-source
;;       '((name . "E helm source")
;;         (candidates . (("one" . "1") ("two" . "2")))
;;         (filter-one-by-one . (lambda (candidates) candidates))
;;         (action . message)))

;; (helm :sources '(e-helm-source))


;;; Demo 07 --- Still use (Dispaly . Real)

(setq data `(,(cons "one"   (list :number "1" :chinese "一"))
             ,(cons "two"   (list :number "2" :chinese "二"))
             ,(cons "three" (list :number "3" :chinese "三"))))

(setq g-helm-source
      `((name . "G helm source")
        (candidates . data)
        (action . ,(helm-make-actions
                    "Show number" (lambda (cand)
                                    (message (plist-get cand :number)))
                    "Show Chinese" (lambda (cand)
                                     (message (plist-get cand :chinese)))))))

(helm :sources '(g-helm-source))