@@ -6,12 +6,12 @@ (provide save-uploaded-file-and-return-filename!) -(declare-setting *PATH_TO_FILEDATA* (build-path (current-directory) "uploaded-files")) +(declare-setting *PATH_TO_UPLOADED_FILES* (build-path (current-directory) "uploaded-files")) (define (save-uploaded-file-and-return-filename! file-data) (let* ((filename (fresh-filename-id (binding/string:file-filename file-data))) (raw-file-bytes (binding/string:file-content file-data)) - (fport (open-output-file (build-path (setting *PATH_TO_FILEDATA*) filename) + (fport (open-output-file (build-path (setting *PATH_TO_UPLOADED_FILES*) filename) #:exists 'error))) (write-bytes raw-file-bytes fport) (close-output-port fport) @@ -19,6 +19,6 @@ (define (fresh-filename-id filename #:id-length (id-length 5)) (let ((try (string-append (random-key-string id-length) "-" filename))) - (if (file-exists? (build-path (setting *PATH_TO_FILEDATA*) try)) + (if (file-exists? (build-path (setting *PATH_TO_UPLOADED_FILES*) try)) (fresh-filename-id filename #:id-length id-length) try))) files.scm @@ -1,5 +1,5 @@ <!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd"> -<html><head><meta http-equiv="content-type" content="text-html; charset=utf-8" /><title>LeftParen 0.4 Documentation</title><link rel="stylesheet" type="text/css" href="scribble.css" title="default" /><script type="text/javascript" src="scribble-common.js"></script></head><body><div class="tocset"><div class="tocview"><div class="tocviewlist" style="margin-bottom: 1em;"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">►</a></td><td></td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html" class="tocviewselflink">Left Paren 0.4 Documentation</a></td></tr></table></div><div class="tocviewsublistonly" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.Installing_.Left.Paren)" class="tocviewlink">Installing Left Paren</a></td></tr><tr><td align="right">2 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._tutorials)" class="tocviewlink">Tutorials</a></td></tr><tr><td align="right">3 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.More_.Documentation_to_.Come)" class="tocviewlink">More Documentation to Come</a></td></tr><tr><td align="right">4 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.Reference)" class="tocviewlink">Reference</a></td></tr><tr><td align="right">5 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.About_.Acknowledgements)" class="tocviewlink">About/ Acknowledgements</a></td></tr></table></div></div></div><div class="tocsub"><table class="tocsublist" cellspacing="0"><tr><td>1<tt> </tt><a href="#(part._.Installing_.Left.Paren)" class="tocsubseclink">Installing Left Paren</a></td></tr><tr><td>2<tt> </tt><a href="#(part._tutorials)" class="tocsubseclink">Tutorials</a></td></tr><tr><td>2.1<tt> </tt><a href="#(part._.Hello__.World)" class="tocsubseclink">Hello, World</a></td></tr><tr><td>2.2<tt> </tt><a href="#(part._.Blogerton_the_.Blog)" class="tocsubseclink">Blogerton the Blog</a></td></tr><tr><td>2.2.1<tt> </tt><a href="#(part._.Changes_to_app_scm)" class="tocsubseclink">Changes to app.scm</a></td></tr><tr><td>2.2.2<tt> </tt><a href="#(part._.Changes_to_main_scm)" class="tocsubseclink">Changes to main.scm</a></td></tr><tr><td>2.2.3<tt> </tt><a href="#(part._.Launch_.Blogerton)" class="tocsubseclink">Launch Blogerton</a></td></tr><tr><td>3<tt> </tt><a href="#(part._.More_.Documentation_to_.Come)" class="tocsubseclink">More Documentation to Come</a></td></tr><tr><td>4<tt> </tt><a href="#(part._.Reference)" class="tocsubseclink">Reference</a></td></tr><tr><td>4.1<tt> </tt><a href="#(part._.Forms)" class="tocsubseclink">Forms</a></td></tr><tr><td>4.2<tt> </tt><a href="#(part._.Sessions)" class="tocsubseclink">Sessions</a></td></tr><tr><td>4.2.1<tt> </tt><a href="#(part._.Creating_sessions)" class="tocsubseclink">Creating sessions</a></td></tr><tr><td>4.2.2<tt> </tt><a href="#(part._.Accessing_sessions)" class="tocsubseclink">Accessing sessions</a></td></tr><tr><td>5<tt> </tt><a href="#(part._.About_.Acknowledgements)" class="tocsubseclink">About/ Acknowledgements</a></td></tr><tr><td>5.1<tt> </tt><a href="#(part._.Contributors)" class="tocsubseclink">Contributors</a></td></tr></table></div></div><div class="maincolumn"><div class="main"><div class="versionbox">Version: 4.1.0.3</div><div class="navset" style="margin-bottom: 2em; border-bottom: 2px solid #e0e0c0;"><input style="width: 16em; margin: 0px; padding: 0px; background-color: #eee; color: #888; border: 1px solid #ddd; text-align: center; vertical-align: middle;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "4.1.0.3", "");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }" />   </div><h2><a name="(part._.Left.Paren_0_4_.Documentation)"></a>LeftParen 0.4 Documentation</h2>Website: <a href="http://leftparen.com">http://leftparen.com</a>LeftParen is a framework for quickly creating web apps. It runs on +<html><head><meta http-equiv="content-type" content="text-html; charset=utf-8" /><title>LeftParen 0.4 Documentation</title><link rel="stylesheet" type="text/css" href="scribble.css" title="default" /><script type="text/javascript" src="scribble-common.js"></script></head><body><div class="tocset"><div class="tocview"><div class="tocviewlist" style="margin-bottom: 1em;"><div class="tocviewtitle"><table cellspacing="0" cellpadding="0"><tr><td style="width: 1em;"><a href="javascript:void(0);" title="Expand/Collapse" class="tocviewtoggle" onclick="TocviewToggle(this,"tocview_0");">►</a></td><td></td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html" class="tocviewselflink">Left Paren 0.4 Documentation</a></td></tr></table></div><div class="tocviewsublistonly" style="display: none;" id="tocview_0"><table cellspacing="0" cellpadding="0"><tr><td align="right">1 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.Installing_.Left.Paren)" class="tocviewlink">Installing Left Paren</a></td></tr><tr><td align="right">2 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._tutorials)" class="tocviewlink">Tutorials</a></td></tr><tr><td align="right">3 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.Reference)" class="tocviewlink">Reference</a></td></tr><tr><td align="right">4 </td><td><a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._.About_.Acknowledgements)" class="tocviewlink">About/ Acknowledgements</a></td></tr></table></div></div></div><div class="tocsub"><table class="tocsublist" cellspacing="0"><tr><td>1<tt> </tt><a href="#(part._.Installing_.Left.Paren)" class="tocsubseclink">Installing Left Paren</a></td></tr><tr><td>2<tt> </tt><a href="#(part._tutorials)" class="tocsubseclink">Tutorials</a></td></tr><tr><td>2.1<tt> </tt><a href="#(part._.Hello__.World)" class="tocsubseclink">Hello, World</a></td></tr><tr><td>2.2<tt> </tt><a href="#(part._.Blogerton_the_.Blog)" class="tocsubseclink">Blogerton the Blog</a></td></tr><tr><td>2.2.1<tt> </tt><a href="#(part._.Changes_to_app_scm)" class="tocsubseclink">Changes to app.scm</a></td></tr><tr><td>2.2.2<tt> </tt><a href="#(part._.Changes_to_main_scm)" class="tocsubseclink">Changes to main.scm</a></td></tr><tr><td>2.2.3<tt> </tt><a href="#(part._.Launch_.Blogerton)" class="tocsubseclink">Launch Blogerton</a></td></tr><tr><td>3<tt> </tt><a href="#(part._.Reference)" class="tocsubseclink">Reference</a></td></tr><tr><td>3.1<tt> </tt><a href="#(part._.Forms)" class="tocsubseclink">Forms</a></td></tr><tr><td>3.1.1<tt> </tt><a href="#(part._.Image_uploads)" class="tocsubseclink">Image uploads</a></td></tr><tr><td>3.2<tt> </tt><a href="#(part._.Sessions)" class="tocsubseclink">Sessions</a></td></tr><tr><td>3.2.1<tt> </tt><a href="#(part._.Creating_sessions)" class="tocsubseclink">Creating sessions</a></td></tr><tr><td>3.2.2<tt> </tt><a href="#(part._.Accessing_sessions)" class="tocsubseclink">Accessing sessions</a></td></tr><tr><td>4<tt> </tt><a href="#(part._.About_.Acknowledgements)" class="tocsubseclink">About/ Acknowledgements</a></td></tr><tr><td>4.1<tt> </tt><a href="#(part._.Contributors)" class="tocsubseclink">Contributors</a></td></tr></table></div></div><div class="maincolumn"><div class="main"><div class="versionbox">Version: 4.1.0.3</div><div class="navset" style="margin-bottom: 2em; border-bottom: 2px solid #e0e0c0;"><input style="width: 16em; margin: 0px; padding: 0px; background-color: #eee; color: #888; border: 1px solid #ddd; text-align: center; vertical-align: middle;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "4.1.0.3", "");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }" />   </div><h2><a name="(part._.Left.Paren_0_4_.Documentation)"></a>LeftParen 0.4 Documentation</h2>Website: <a href="http://leftparen.com">http://leftparen.com</a>LeftParen is a framework for quickly creating web apps. It runs on PLT Scheme v4.1 or greater. LeftParen is released under an <a href="http://github.com/vegashacker/leftparen/tree/master/MIT-LICENSE.txt">MIT License</a>. The source is available on <a href="http://github.com/vegashacker/leftparen/tree/master">github</a>.<h3>1<tt> </tt><a name="(part._.Installing_.Left.Paren)"></a>Installing LeftParen</h3>You’ll need PLT Scheme v4.1 or greater installed.Make sure that mzscheme is in your path. You should be ready to go if you can do this:<table cellspacing="0"><tr><td>% mzscheme</td></tr><tr><td>Welcome to MzScheme v4.1...</td></tr><tr><td>></td></tr></table>Installing LeftParen is done behind the scenes with a <a href="http://planet.plt-scheme.org/">PLaneT</a> require. See <a href="file:///Users/rob/Documents/git-leftparen/scribblings/leftparen.html#(part._tutorials)">Tutorials</a> for an example of this. When you -first issue one of these require commands, you’ll automatically download the LeftParen files to your local PLaneT cache. This can sometimes take a few moments, so be prepared to wait a bit.<h3>2<tt> </tt><a name="(part._tutorials)"></a>Tutorials</h3><h4>2.1<tt> </tt><a name="(part._.Hello__.World)"></a>Hello, World</h4>We’re going to make a project called hello-world. Change to the directory that you’d like to make the project in. Then issue<table cellspacing="0"><tr><td>% mzscheme -e '(require (planet "bootstrap.scm" ("vegashacker" "leftparen.plt" 3 0)))' project hello-world</td></tr></table>This will create a hello-world project directory for you. In this directory you’ll find the script directory, which contains some useful scripts. All paths are relative to this project directory, so when calling scripts, you always want to be at the project root.<table cellspacing="0"><tr><td>% cd hello-world</td></tr></table>We need to make the scripts executable:<table cellspacing="0"><tr><td>% chmod u+x script/*</td></tr></table>LeftParen has automatically generated everything we need to run our web app – we just need to start the server (again, you should be at the project root directory):<table cellspacing="0"><tr><td>% ./script/server</td></tr><tr><td>Web server started on port 8765</td></tr><tr><td>Listening on IP address: 127.0.0.1</td></tr><tr><td>Type stop to stop the server and exit</td></tr><tr><td>Type restart to restart the server</td></tr></table>Point your browser to <a href="http://localhost:8765">http://localhost:8765</a> and you should see a familiar greeting:Hello, World!<h4>2.2<tt> </tt><a name="(part._.Blogerton_the_.Blog)"></a>Blogerton the Blog</h4>Now let’s try implementing the true "hello world" of web apps – a blog. First, execute the following commands from the directory in which you want to create your project directory:<table cellspacing="0"><tr><td>% mzscheme -e '(require (planet "bootstrap.scm" ("vegashacker" "leftparen.plt" 3 0)))' project blogerton</td></tr><tr><td>% cd blogerton</td></tr><tr><td>% chmod u+x script/*</td></tr></table><h5>2.2.1<tt> </tt><a name="(part._.Changes_to_app_scm)"></a>Changes to app.scm</h5>We need to register a couple of pages in our app. The index-page was already set up for you, but you’ll need to add a page to create new posts, and one to view them. Make the define-app call look like this:<table cellspacing="0" class="schemeblock"><tr><td>  (define-app my-app</td></tr><tr><td>    (index-page (url "/"))</td></tr><tr><td>    (create-post-page (url "/post"))</td></tr><tr><td>    (view-post-page (url "/view/" (string-arg))))</td></tr></table><h5>2.2.2<tt> </tt><a name="(part._.Changes_to_main_scm)"></a>Changes to main.scm</h5>Now we need to define those pages that we declared in app.scm.<table cellspacing="0" class="schemeblock"><tr><td>  (define-page (index-page req)</td></tr><tr><td>    (** `(h1 "Blogerton")</td></tr><tr><td>        `(p ,(web-link "Create a new post" (page-url create-post-page)))</td></tr><tr><td>        `(ul ,@(map (lambda (p) `(li ,(paint-blog-post p)))</td></tr><tr><td>                    (load-where '((type . blog-post))</td></tr><tr><td>                                #:sort-by 'created-at #:compare >)))))</td></tr><tr><td>  </td></tr><tr><td>  (define-page (create-post-page req)</td></tr><tr><td>    (form '((title "Title" text) (body "Body" long-text))</td></tr><tr><td>          #:init '((type . blog-post))</td></tr><tr><td>          #:on-done (lambda (post) (redirect-to-page view-post-page (rec-id post)))))</td></tr><tr><td>  </td></tr><tr><td>  (define-page (view-post-page req post-id)</td></tr><tr><td>    (paint-blog-post (load-rec post-id #:ensure '((type . blog-post)))))</td></tr><tr><td>  </td></tr><tr><td>  (define (paint-blog-post post)</td></tr><tr><td>    `(div (h2 ,(rec-prop post 'title))</td></tr><tr><td>          (p ,(rec-prop post 'body))))</td></tr></table><h5>2.2.3<tt> </tt><a name="(part._.Launch_.Blogerton)"></a>Launch Blogerton</h5>You’re ready for launch. Start the server with<table cellspacing="0"><tr><td>% ./script/server</td></tr></table>and you should have a basic blogging app, with persistent data, in 19 lines of code.<h3>3<tt> </tt><a name="(part._.More_.Documentation_to_.Come)"></a>More Documentation to Come</h3>We need to get a full LeftParen reference up (not just simple tutorials). There’s lots more cool stuff in LeftParen that this document doesn’t yet address.<h3>4<tt> </tt><a name="(part._.Reference)"></a>Reference</h3><h4>4.1<tt> </tt><a name="(part._.Forms)"></a>Forms</h4>Wouldn’t forms documentation be nice?<table cellspacing="0" class="boxed"><tr><td>(mystery a) → int</td></tr><tr><td>  a : string-dude</td></tr></table><h4>4.2<tt> </tt><a name="(part._.Sessions)"></a>Sessions</h4>A session is an object that allows you to easily store state about individual visitors to your web app. Sessions are stored on the server as a record with a virtually impossible-to-guess id. A cookie is left in the user’s web browser, which contains a pointer to a particular session id. These cookies expire one month after creation and, currently, this can’t be changed.<h5>4.2.1<tt> </tt><a name="(part._.Creating_sessions)"></a>Creating sessions</h5><table cellspacing="0" class="boxed"><tr><td><table cellspacing="0" class="schemeblock"><tr><td>(define-session-page</td></tr><tr><td>  (page-name request-iden session-iden page-args ...)</td></tr><tr><td>  body ...)</td></tr></table></td></tr></table>This is an alternate to define-page, most commonly used in main.scm. The only difference is that after the request identifier, you must provide a session identifier. For example, to keep a counter (unique to each user), you could write:<table cellspacing="0" class="schemeblock"><tr><td>  (define-session-page (foo-page req sesh)</td></tr><tr><td>    (let ((c (session-get-val sesh 'counter 0)))</td></tr><tr><td>      (session-put-val! sesh 'counter (+ 1 c))</td></tr><tr><td>      (number->string c)))</td></tr></table>When you define a session page, the session is automatically fetched for you (and created if necessary), and bound to the session identifier you provided.<h5>4.2.2<tt> </tt><a name="(part._.Accessing_sessions)"></a>Accessing sessions</h5><table cellspacing="0" class="boxed"><tr><td>(session-get-val session key [missing-val]) → any</td></tr><tr><td>  session : session</td></tr><tr><td>  key : symbol</td></tr><tr><td>  missing-val : any = #f</td></tr></table><table cellspacing="0" class="boxed"><tr><td>(session-put-val! session key val) → session</td></tr><tr><td>  session : session</td></tr><tr><td>  key : symbol</td></tr><tr><td>  val : any</td></tr></table><h3>5<tt> </tt><a name="(part._.About_.Acknowledgements)"></a>About/Acknowledgements</h3>LeftParen was written by <a href="http://robhunter.org">Rob Hunter</a>, but it builds heavily on (and, in fact, often directly incorporates) the work of <a href="http://untyped.com/">Untyped</a> (<a href="http://planet.plt-scheme.org/display.ss?package=instaservlet.plt&owner=untyped">instaservlet</a> and <a href="http://planet.plt-scheme.org/display.ss?package=dispatch.plt&owner=untyped">dispatch</a>), <a href="http://scheme.dk/blog/">Jens Axel Soegaard</a> (<a href="http://planet.plt-scheme.org/display.ss?package=web.plt&owner=soegaard">web.plt</a>), and of course, <a href="http://www.plt-scheme.org/">PLT Scheme</a>.<h4>5.1<tt> </tt><a name="(part._.Contributors)"></a>Contributors</h4><ul><li>Bill Hager</li><li>Joshua Herman</li></ul><div class="navset" style="margin-top: 2em; border-top: 2px solid #e0e0c0;"><input style="width: 16em; margin: 0px; padding: 0px; background-color: #eee; color: #888; border: 1px solid #ddd; text-align: center; vertical-align: middle;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "4.1.0.3", "");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }" />   </div></div></div></body></html> \ No newline at end of file +first issue one of these require commands, you’ll automatically download the LeftParen files to your local PLaneT cache. This can sometimes take a few moments, so be prepared to wait a bit.<h3>2<tt> </tt><a name="(part._tutorials)"></a>Tutorials</h3><h4>2.1<tt> </tt><a name="(part._.Hello__.World)"></a>Hello, World</h4>We’re going to make a project called hello-world. Change to the directory that you’d like to make the project in. Then issue<table cellspacing="0"><tr><td>% mzscheme -e '(require (planet "bootstrap.scm" ("vegashacker" "leftparen.plt" 3 0)))' project hello-world</td></tr></table>This will create a hello-world project directory for you. In this directory you’ll find the script directory, which contains some useful scripts. All paths are relative to this project directory, so when calling scripts, you always want to be at the project root.<table cellspacing="0"><tr><td>% cd hello-world</td></tr></table>We need to make the scripts executable:<table cellspacing="0"><tr><td>% chmod u+x script/*</td></tr></table>LeftParen has automatically generated everything we need to run our web app – we just need to start the server (again, you should be at the project root directory):<table cellspacing="0"><tr><td>% ./script/server</td></tr><tr><td>Web server started on port 8765</td></tr><tr><td>Listening on IP address: 127.0.0.1</td></tr><tr><td>Type stop to stop the server and exit</td></tr><tr><td>Type restart to restart the server</td></tr></table>Point your browser to <a href="http://localhost:8765">http://localhost:8765</a> and you should see a familiar greeting:Hello, World!<h4>2.2<tt> </tt><a name="(part._.Blogerton_the_.Blog)"></a>Blogerton the Blog</h4>Now let’s try implementing the true "hello world" of web apps – a blog. First, execute the following commands from the directory in which you want to create your project directory:<table cellspacing="0"><tr><td>% mzscheme -e '(require (planet "bootstrap.scm" ("vegashacker" "leftparen.plt" 3 0)))' project blogerton</td></tr><tr><td>% cd blogerton</td></tr><tr><td>% chmod u+x script/*</td></tr></table><h5>2.2.1<tt> </tt><a name="(part._.Changes_to_app_scm)"></a>Changes to app.scm</h5>We need to register a couple of pages in our app. The index-page was already set up for you, but you’ll need to add a page to create new posts, and one to view them. Make the define-app call look like this:<table cellspacing="0" class="schemeblock"><tr><td>  (define-app my-app</td></tr><tr><td>    (index-page (url "/"))</td></tr><tr><td>    (create-post-page (url "/post"))</td></tr><tr><td>    (view-post-page (url "/view/" (string-arg))))</td></tr></table><h5>2.2.2<tt> </tt><a name="(part._.Changes_to_main_scm)"></a>Changes to main.scm</h5>Now we need to define those pages that we declared in app.scm.<table cellspacing="0" class="schemeblock"><tr><td>  (define-page (index-page req)</td></tr><tr><td>    (** `(h1 "Blogerton")</td></tr><tr><td>        `(p ,(web-link "Create a new post" (page-url create-post-page)))</td></tr><tr><td>        `(ul ,@(map (lambda (p) `(li ,(paint-blog-post p)))</td></tr><tr><td>                    (load-where '((type . blog-post))</td></tr><tr><td>                                #:sort-by 'created-at #:compare >)))))</td></tr><tr><td>  </td></tr><tr><td>  (define-page (create-post-page req)</td></tr><tr><td>    (form '((title "Title" text) (body "Body" long-text))</td></tr><tr><td>          #:init '((type . blog-post))</td></tr><tr><td>          #:on-done (lambda (post) (redirect-to-page view-post-page (rec-id post)))))</td></tr><tr><td>  </td></tr><tr><td>  (define-page (view-post-page req post-id)</td></tr><tr><td>    (paint-blog-post (load-rec post-id #:ensure '((type . blog-post)))))</td></tr><tr><td>  </td></tr><tr><td>  (define (paint-blog-post post)</td></tr><tr><td>    `(div (h2 ,(rec-prop post 'title))</td></tr><tr><td>          (p ,(rec-prop post 'body))))</td></tr></table><h5>2.2.3<tt> </tt><a name="(part._.Launch_.Blogerton)"></a>Launch Blogerton</h5>You’re ready for launch. Start the server with<table cellspacing="0"><tr><td>% ./script/server</td></tr></table>and you should have a basic blogging app, with persistent data, in 19 lines of code.<h3>3<tt> </tt><a name="(part._.Reference)"></a>Reference</h3><h4>3.1<tt> </tt><a name="(part._.Forms)"></a>Forms</h4>Most web applications make some use of web forms. The form function lets easily you get and process input from your users.<table cellspacing="0" class="boxed"><tr><td>(form field-specs) → xexpr?</td></tr><tr><td>  field-specs : (listof field-spec?)</td></tr></table><table cellspacing="0" class="boxed"><tr><td>field-spec? : (list symbol? string? field-type?)</td></tr></table><table cellspacing="0" class="boxed"><tr><td><table cellspacing="0" class="argcontract"><tr><td>field-type? : </td><td><table cellspacing="0" class="schemeblock"><tr><td>(or/c 'text 'long-text 'number 'password 'image 'checkbox</td></tr><tr><td>      'radio 'drop-down)</td></tr></table></td></tr></table></td></tr></table>You create a form by listing, in order, "field specifications". For example, you might want a title field, followed by a description text box, followed by a photo upload field. Note that the many keyword arguments available to the form function aren’t documented yet.Each field spec is of the form (field-name label field-type). For example, you create a title field, you might use the spec (title "Enter a title" text). The entire example metioned above might look like this:<table cellspacing="0" class="schemeblock"><tr><td>  (form '((title "Title" text)</td></tr><tr><td>          (description "Description" long-text)</td></tr><tr><td>          (photo "Your photo" image)))</td></tr></table><h5>3.1.1<tt> </tt><a name="(part._.Image_uploads)"></a>Image uploads</h5>By default, uploaded images are stored in the uploaded-files directory in your project directory. You can customize this with the *PATH_TO_UPLOADED_FILES* setting. When images are saved, their original filenames are used with a 5-character code pre-pended to make filenames unique.<h4>3.2<tt> </tt><a name="(part._.Sessions)"></a>Sessions</h4>A session is an object that allows you to easily store state about individual visitors to your web app. Sessions are stored on the server as a record with a virtually impossible-to-guess id. A cookie is left in the user’s web browser, which contains a pointer to a particular session id. These cookies expire one month after creation and, currently, this can’t be changed.<h5>3.2.1<tt> </tt><a name="(part._.Creating_sessions)"></a>Creating sessions</h5><table cellspacing="0" class="boxed"><tr><td><table cellspacing="0" class="schemeblock"><tr><td>(define-session-page</td></tr><tr><td>  (page-name request-iden session-iden page-args ...)</td></tr><tr><td>  body ...)</td></tr></table></td></tr></table>This is an alternate to define-page, most commonly used in main.scm. The only difference is that after the request identifier, you must provide a session identifier. For example, to keep a counter (unique to each user), you could write:<table cellspacing="0" class="schemeblock"><tr><td>  (define-session-page (foo-page req sesh)</td></tr><tr><td>    (let ((c (session-get-val sesh 'counter 0)))</td></tr><tr><td>      (session-put-val! sesh 'counter (+ 1 c))</td></tr><tr><td>      (number->string c)))</td></tr></table>When you define a session page, the session is automatically fetched for you (and created if necessary), and bound to the session identifier you provided.<h5>3.2.2<tt> </tt><a name="(part._.Accessing_sessions)"></a>Accessing sessions</h5><table cellspacing="0" class="boxed"><tr><td>(session-get-val session key [missing-val]) → any</td></tr><tr><td>  session : session</td></tr><tr><td>  key : symbol</td></tr><tr><td>  missing-val : any = #f</td></tr></table><table cellspacing="0" class="boxed"><tr><td>(session-put-val! session key val) → session</td></tr><tr><td>  session : session</td></tr><tr><td>  key : symbol</td></tr><tr><td>  val : any</td></tr></table><h3>4<tt> </tt><a name="(part._.About_.Acknowledgements)"></a>About/Acknowledgements</h3>LeftParen was written by <a href="http://robhunter.org">Rob Hunter</a>, but it builds heavily on (and, in fact, often directly incorporates) the work of <a href="http://untyped.com/">Untyped</a> (<a href="http://planet.plt-scheme.org/display.ss?package=instaservlet.plt&owner=untyped">instaservlet</a> and <a href="http://planet.plt-scheme.org/display.ss?package=dispatch.plt&owner=untyped">dispatch</a>), <a href="http://scheme.dk/blog/">Jens Axel Soegaard</a> (<a href="http://planet.plt-scheme.org/display.ss?package=web.plt&owner=soegaard">web.plt</a>), and of course, <a href="http://www.plt-scheme.org/">PLT Scheme</a>.<h4>4.1<tt> </tt><a name="(part._.Contributors)"></a>Contributors</h4><ul><li>Bill Hager</li><li>Joshua Herman</li></ul><div class="navset" style="margin-top: 2em; border-top: 2px solid #e0e0c0;"><input style="width: 16em; margin: 0px; padding: 0px; background-color: #eee; color: #888; border: 1px solid #ddd; text-align: center; vertical-align: middle;" type="text" value="...search manuals..." title="Enter a search string to search the manuals" onkeypress="return DoSearchKey(event, this, "4.1.0.3", "");" onfocus="this.style.color="black"; this.style.textAlign="left"; if (this.value == "...search manuals...") this.value="";" onblur="if (this.value.match(/^ *$/)) { this.style.color="#888"; this.style.textAlign="center"; this.value="...search manuals..."; }" />   </div></div></div></body></html> \ No newline at end of file scribblings/leftparen.html @@ -108,17 +108,31 @@ You're ready for launch. Start the server with and you should have a basic blogging app, with persistent data, in 19 lines of code. -@section{More Documentation to Come} - -We need to get a full LeftParen reference up (not just simple tutorials). There's lots more cool stuff in LeftParen that this document doesn't yet address. - @section{Reference} @subsection{Forms} -Wouldn't forms documentation be nice? +Most web applications make some use of web forms. The @scheme[form] function lets easily you get and process input from your users. + +@defproc[(form (field-specs (listof field-spec?))) xexpr?] +@defthing[field-spec? (list symbol? string? field-type?)] +@defthing[field-type? (or/c 'text 'long-text 'number 'password 'image 'checkbox + 'radio 'drop-down)] + +You create a form by listing, in order, "field specifications". For example, you might want a title field, followed by a description text box, followed by a photo upload field. Note that the many keyword arguments available to the @scheme[form] function aren't documented yet. + +Each field spec is of the form @scheme[(field-name label field-type)]. For example, you create a title field, you might use the spec @scheme[(title "Enter a title" text)]. The entire example metioned above might look like this: + +@schemeblock[ +(form '((title "Title" text) + (description "Description" long-text) + (photo "Your photo" image))) +] + + +@subsubsection{Image uploads} -@defproc[(mystery (a string-dude)) int] +By default, uploaded images are stored in the @tt{uploaded-files} directory in your project directory. You can customize this with the @scheme[*PATH_TO_UPLOADED_FILES*] setting. When images are saved, their original filenames are used with a 5-character code pre-pended to make filenames unique. @subsection{Sessions} scribblings/leftparen.scrbl 1819cb29a0799dc77d86b38d26da456dd9588605 Rob Hunter rob.hunter@gmail.com http://github.com/vegashacker/leftparen/commit/9221a858d42a0625b625cb6eaa2dc1b222430111 9221a858d42a0625b625cb6eaa2dc1b222430111

2008-11-10T09:29:43-08:00

changed name of file upload setting; added documention for some parts of the 'form' functionality 189a2515522d0f2c054ccaa489b57f773e8dffe1 Rob Hunter rob.hunter@gmail.com