Trouble with building up a string in Clojure
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Aki Iskandar
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Published on 2011-01-08T23:35:08Z
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2011/01/09
0:54 UTC
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clojure
Hi gang - [this may seem like my problem is with Compojure, but it isn't - it's with Clojure]
I've been pulling my hair out on this seemingly simple issue - but am getting nowhere.
I am playing with Compojure (a light web framework for Clojure) and I would just like to generate a web page showing showing my list of todos that are in a PostgreSQL database.
The code snippets are below (left out the database connection, query, etc - but that part isn't needed because specific issue is that the resulting HTML shows nothing between the <body> and </body> tags).
As a test, I tried hard-coding the string in the call to main-layout, like this: (html (main-layout "Aki's Todos" "Haircut<br>Study Clojure<br>Answer a question on Stackoverfolw")) - and it works fine.
So the real issue is that I do not believe I know how to build up a string in Clojure. Not the idiomatic way, and not by calling out to Java's StringBuilder either - as I have attempted to do in the code below.
A virtual beer, and a big upvote to whoever can solve it! Many thanks!
=============================================================
;The master template (a very simple POC for now, but can expand on it later)
(defn main-layout
"This is one of the html layouts for the pages assets - just like a master page"
[title body]
(html
[:html
[:head
[:title title]
(include-js "todos.js")
(include-css "todos.css")]
[:body body]]))
(defn show-all-todos
"This function will generate the todos HTML table and call the layout function"
[]
(let [rs (select-all-todos)
sbHTML (new StringBuilder)]
(for [rec rs]
(.append sbHTML (str rec "<br><br>")))
(html (main-layout "Aki's Todos" (.toString sbHTML)))))
=============================================================
Again, the result is a web page but with nothing between the body tags. If I replace the code in the for loop with println statements, and direct the code to the repl - forgetting about the web page stuff (ie. the call to main-layout), the resultset gets printed - BUT - the issue is with building up the string.
Thanks again.
~Aki
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