Errata

In Chapter 2: Using lein-cljsbuild

lein trampoline cljsbuild repl-rhino

may fail on Windows 7 (with/maybe without cygwin)

A workaround: you're going to have to hack the "lein" bash file:

around line 44: LEIN_JAR="$LEIN_HOME\self-installs\leiningen-$LEIN_VERSION-standalone.jar"

towards the very end:

if [ -r "$TRAMPOLINE_FILE" ]; then
TRAMPOLINE=$(gawk '{ gsub(/\\"/,""); print }' $TRAMPOLINE_FILE)
if [ "$INPUT_CHECKSUM" = "" ]; then
rm $TRAMPOLINE_FILE
fi
exec sh -c "exec $TRAMPOLINE"
else
exit $EXIT_CODE
fi

Modify the very end of the lein script to remove the double double quotes. Possibly you may have to replace colons (:) with semi-colons (;) in CLASSPATHs.

Chap 2. No page numbers online.

In the directory structure, resources/public is a subdir for a separate top level dir called "hello_world". Everything else is under "hello-world".

In Safari Books Online I don't see a way to read the page number....

Anyway, in Chapter 2 - Hello world, Paragraph "Using lein-cljsbuild" there is a minor technical mistake. You do not need to include clojurescript dependency is you add lein-cljsbuild to :pluings keyword in project.clj

Best regards

Mimmo Cosenza

This should probably be classes as a "version discrepancy" as I think that is what it is. But the book encourages you to get the latest versions of everything, and then presents a project.clj file which has this as the last line:

:cljsbuild {:builds []})

A :cljsbuild with an empty :builds entry will generate the following error under Clojure 1.5.1 or 1.6.0, using ClojureScript 2268 and lein-cljsbuild 1.0.3 (and probably many other version combos as well):

"java.lang.ClassCastException: clojure.lang.PersistentList cannot be cast to clojure.lang.Associative"

If you remove the line completely, you'll get a warning about this "format being deprecated", and you're probably best off using one of the example :cljsbuild entries from the lein-cljs git repository until you figure out what this parameter is for.

First, noting again error noted in Feb 02, 2013 comment from "prasad rao":

Page 18: "Finally, create an HTML file at public/resources/index.html:"
Page 18: {:output-to "resources/public/hello.js"

More important, following the steps in this section: The code is integrated into the final compiled/optimized Javascript but the browser shows an error ("cannot set property Mb of undefined"). I went back to the previous chapter code, since there didn't seem to be any difference, and tried the same steps there with no luck. (Sometimes I got the tightly compressed JS output, while others I just got three lines of "goog.addDependency", but I couldn't figure out what I was doing to cause that.)

This may be a version issue.

States that ClojureScript does not support "Refs and Vars". This should probably be "Refs and Agents", as Vars would be supported by clojure and clojurescript equally.

The index.html is directed to be created at public/resources/index.html. The output-to file in the compile command is given as resources/public/hello.js. Both the directories need to be the same.