Remove SQL steps from 'Hello World' web section

Author: weavejester

index.adoc

@@ -539,7 +539,7 @@ While Duct can be used for any server-side application, its most common
 use-case is developing web applications and services. This section will
 take you through writing a '`todo list`' web application in Duct.
 
-=== Hello World Wide Web
+=== Hello World
 
 We'll begin by creating a new project directory.
 
@@ -549,24 +549,16 @@ mkdir todo-app && cd todo-app
 ----
 
 The first thing we'll need is a `deps.edn` file that to provide the
-project dependencies. This will include Duct main and three additional
-modules: logging, sql and web.
-
-https://www.sqlite.org/index.html[SQLite] will be our database, so we'll
-need the SQLite JDBC adapter as well. To give us a Clojure-friendly way
-of querying the database, we'll also add
-https://github.com/seancorfield/next-jdbc[next.jdbc].
+project dependencies. This will include Duct main and two additional
+modules: logging and web.
 
 .deps.edn
 [,clojure]
 ----
 {:deps {org.clojure/clojure {:mvn/version "1.12.0"}
         org.duct-framework/main {:mvn/version "0.1.3"}
         org.duct-framework/module.logging {:mvn/version "0.6.5"}
-        org.duct-framework/module.sql {:mvn/version "0.7.1"}
-        org.duct-framework/module.web {:mvn/version "0.11.0"}
-        org.xerial/sqlite-jdbc {:mvn/version "3.47.0.0"}
-        com.github.seancorfield/next.jdbc {:mvn/version "1.3.955"}}
+        org.duct-framework/module.web {:mvn/version "0.11.1"}}
  :aliases {:duct {:main-opts ["-m" "duct.main"]}}}
 ----
 
@@ -578,106 +570,41 @@ is the default directory Clojure uses to store source files.
 $ mkdir src
 ----
 
+IMPORTANT: It is especially important to ensure the source directory
+exists before starting a REPL, otherwise the REPL will not be able to
+load source changes.
+
 As this is a Duct application, we'll need a `duct.edn` file. This will
-contain the three modules we added to the project's dependencies.
+contain the two modules we added to the project's dependencies.
 
 .duct.edn
 [,clojure]
 ----
 {:system
  {:duct.module/logging {}
-  :duct.module/sql {}
-  :duct.module/web {}}}
-----
-
-Will this minimal configuration work? Let's find out.
-
-[,shell]
-----
-duct --main
-✗ Initiating system...
-Execution error (ExceptionInfo) at integrant.core/unbound-vars-exception (core.cljc:343).
-Unbound vars: jdbc-url
-
-Full report at:
-/tmp/clojure-14769356862243778775.edn
-----
-
-Oh dear, it looks like there's a configuration var, `jdbc-url`, that has
-not been assigned a value. But where did it come from?
-
-In this case it came from the `:duct.module/sql` module. Libraries can
-add their own vars by using Integrant's keyword annotations. We can see
-these new vars if we check the `--help`.
-
-[,shell]
-----
-$ duct --help
-Usage:
-	clojure -M:duct [--main | --repl]
-Options:
-  -c, --cider              Start an NREPL server with CIDER middleware
-      --init               Create a blank duct.edn config file
-  -p, --profiles PROFILES  A concatenated list of profile keys
-  -n, --nrepl              Start an NREPL server
-  -m, --main               Start the application
-  -r, --repl               Start a command-line REPL
-  -s, --show               Print out the expanded configuration and exit
-  -v, --verbose            Enable verbose logging
-  -h, --help               Print this help message and exit
-      --jdbc-url JDBC-URL  The JDBC database URL
-      --port PORT          The HTTP server port (default: 3000)
-----
-
-At the bottom we can see that the modules have added two new options:
-`--jdbc-url` and `--port`. The server port has a default value of 3000,
-but there's no obvious default for a database URL, at least not one
-that will suit every project.
-
-However, we can add own own default by updating the configuration.
-
-.duct.edn
-[,clojure]
-----
-{:vars {jdbc-url {:default "jdbc:sqlite:todo.db"}}
- :system
- {:duct.module/logging {}
-  :duct.module/sql {}
   :duct.module/web {}}}
 ----
 
-Now when we run the application we get a more promising result.
+We can now start the application with `--main`.
 
 [,shell]
 ----
 $ duct --main
 ✓ Initiating system...
-2024-11-25T02:51:08.268Z :warn :duct.migrator.ragtime/missing-file {:path "migrations.edn"}
 2024-11-25T02:51:08.279Z :report :duct.server.http.jetty/starting-server {:port 3000}
 ----
 
-The application warns about a missing `migrations.edn` file, but starts
-up the web server. The web application should now be up and running at:
+The web application should now be up and running at:
 http://localhost:3000/
 
 Visiting that URL will result in a '`404 Not Found`' error page, because
 we have no routes defined. The error page will be in plaintext, because
 we haven't specified what _features_ we want for our web application.
 
 We'll fix both these issues, but before we do we should terminate the
-application with Ctrl-C and make a `src` directory.
-
-[,shell]
-----
-mkdir -p src/todo
-----
-
-IMPORTANT: The source directory must be created before running the REPL.
-This is because Clojure looks for source files in the Java classpath,
-and directories that don't exist yet will be omitted from this.
-
-Then we'll start a REPL. We'll keep this running while we develop the
-application.
+application with Ctrl-C and start a REPL. We'll keep this running while
+we develop the application to avoid costly restarts and to give us a way
+of querying the running system.
 
 [,shell]
 ----
@@ -702,10 +629,8 @@ route to handle a web request to the root of our application.
 .duct.edn
 [,clojure]
 ----
-{:vars {jdbc-url {:default "jdbc:sqlite:todo.db"}}
- :system
+{:system
  {:duct.module/logging {}
-  :duct.module/sql {}
   :duct.module/web
   {:features #{:site}
    :routes [["/" {:get :todo.routes/index}]]}}}