Add two more exercises

Author: mk

deps.edn

@@ -14,6 +14,7 @@
         dk.ative/docjure {:mvn/version "1.16.0"}
         clojusc/wordnet {:mvn/version "1.2.0"}
         clj-jgit/clj-jgit {:mvn/version "1.0.2" :exclusions [org.slf4j/slf4j-api]}
+        scicloj/tablecloth {:mvn/version "7.000-beta-27"}
 
         org.babashka/cli {:mvn/version "0.5.40"}
 

exercises/ex_4_viewer_selection.clj

@@ -0,0 +1,40 @@
+;; # Custom Viewer
+(ns exercises.ex-4-custom-viewer
+  (:require [nextjournal.clerk :as clerk]
+            [nextjournal.clerk.viewer :as viewer]
+            [tablecloth.api :as tc]))
+
+;; Here's a tablecloth `dataset` and a skeleton for a
+;; `dataset-viewer`. Modify the `:transform-fn` of the viewer so Clerk
+;; shows it as a `clerk/table`.
+
+;; You might want to use a table format that preserves the column
+;; ordering.
+
+(def dataset
+  (-> "https://raw.githubusercontent.com/techascent/tech.ml.dataset/master/test/data/stocks.csv"
+      (tc/dataset {:key-fn keyword})
+      (tc/group-by (fn [row]
+                     {:symbol (:symbol row)
+                      :year (tech.v3.datatype.datetime/long-temporal-field :years (:date row))}))
+      (tc/aggregate #(tech.v3.datatype.functional/mean (% :price)))))
+
+(def dataset-viewer
+  {:transform-fn (clerk/update-val (fn [dataset]
+                                     ,,,
+                                     dataset))})
+
+(clerk/with-viewer dataset-viewer
+  dataset)
+
+;; Extend the viewer with a `:pred-fn` that automatically selects it
+;; based on the `tc/dataset?` predicate. Validate that this works
+;; correctly using `viewer/viewer-for`.
+
+;; Finally add the viewer to the namespace using `clerk/add-viewers!`
+;; so the dataset is rendered as a table, without requiring an
+;; explicit `clerk/with-viewer` call.
+
+(clerk/add-viewers! [,,,])
+
+dataset

exercises/ex_4_viewer_presentation.clj renamed to exercises/ex_5_viewer_presentation.clj

@@ -1,6 +1,6 @@
 ;; # Viewer Presentation
 
-(ns exercises.ex-3-viewer-presentation
+(ns exercises.ex-5-viewer-presentation
   (:require [nextjournal.clerk :as clerk]
             [nextjournal.clerk.viewer :as viewer]))
 

exercises/ex_5_caching.clj renamed to exercises/ex_6_caching.clj

@@ -1,5 +1,5 @@
 ;; # Caching
-(ns ex-5-caching
+(ns ex-6-caching
   (:require [nextjournal.clerk :as clerk]))
 
 ;; Note how the following notebook will show the same value

exercises/ex_6_visibility.clj renamed to exercises/ex_7_visibility.clj

@@ -1,4 +1,4 @@
-(ns exercises.ex-6-visibility
+(ns exercises.ex-7-visibility
   (:require [clojure.string :as str]
             [meta-csv.core :as csv]
             [nextjournal.clerk :as clerk]))

exercises/ex_7_viewer_require.clj renamed to exercises/ex_8_viewer_require.clj

@@ -1,5 +1,5 @@
 ;; # Viewer Require
-(ns ex-7-viewer-require
+(ns ex-8-viewer-require
   (:require [nextjournal.clerk :as clerk]))
 
 ;; In this exercise, we'll use the Clerk's viewer api to dynamically

exercises/ex_9_sync.clj

@@ -0,0 +1,33 @@
+;; # Sync
+(ns ex-9-sync
+  (:require [nextjournal.clerk :as clerk]
+            [nextjournal.clerk.experimental :as cx]))
+
+;; A `^{::clerk/sync true}` metadata annotation enables two-way
+;; bindings between the JVM and Clerk's viewer in the browser.
+
+(defonce !text
+  (atom "Hello"))
+
+(defonce !repeat
+  (atom 3))
+
+(repeat @!repeat @!text)
+
+;; Start by evaluating forms in the following `comment` form and show
+;; the notebook again to see it update. Then add a `^{::clerk/sync
+;; true}` metadata annotation and try again.
+
+(comment
+  (reset! !text "Hello, again")
+  (reset! !text "Hello World")
+  (reset! !text "Hello")
+
+  (swap! !repeat inc)
+  (swap! !repeat dec)
+  )
+
+;; Finally, add `::clerk/viewer` with `cx/text-input` and `cx/slider`
+;; values to the metadata annotation. Play with the value propagation
+;; from both the browser and the REPL.
+