There's a good video on building a simple app with Seaside (on Squeak Smalltalk) at this blog.

Here's the missing voice-over:

1. Start your web server (SSKom startOn: 91.)
2. Create a new category named "SeasideBlog"
3. Change the generic class definition to declare BlogView a subclass of WAComponent. Accept.
4. Define a class method canBeRoot, returning true. Accept. (I’m going to stop saying, “Accept.”
5. Define and accept an instance method

renderContentOn: html

html text: 'Hello world!'

1. Browse to your seaside/config site (http://localhost:91/seaside/config, ID=admin/seaside)
   
   1. Add an application entry point “seasideBlog”
   2. Set Root Component = BlogView and click Done

i. If you don’t see BlogView as a choice, you probably defined canBeRoot as an instance method. Oops!

1. 1. Click your new seasideBlog link and confirm that you see “Hello world!”
2. Create a BlogPost class, subclassing Object, with instance variables title, body, and comments.
   
   1. I don’t know what a Magritte description is, but whenever it asks, I tell it to create them.
3. Create a BlogComment class, subclassing Object, with instance variables name and comment.
4. Select name, right-click/selection/create accessors biz simple
5. Select comment, right-click/selection/create accessors biz simple
6. In BlogComment’s class method descriptionName, change priority to 10.
7. In BlogComment’s class method descriptionComment, change priority to 20, and change MAStringDescription to MAMemoDescription
8. BlogPost, (instance): create accessors biz simple for the 3 instance variables.
9. Remove the “comments:” method but not “comments” (without the colon)
10. Select class, delete descriptionComments,
11. Change priority on descriptionTitle to 10
12. Change priority on descriptionBody to 20, and change MAStringDescription to MAMemoDescription
13. Still on BlogPost, create a database method category, and create a class method

repository

^repository ifNil:[repository := OrderedCollection new]

1. 1. When you accept, it will whine about repository. Tell it to create an instance variable.
2. Alphabetize your method categories
3. Insert the following into BlogPost’s descriptionTitle, just before beRequired:

addCondition: [:value | (BlogPost repository contains: [:each | each title = value]) not ]

labelled: 'Post with that title already exists';

1. Select instance and BlogView and renderContentOn and make it’s body look like:

renderContentOn: html BlogPost repository reversed do: [:eachPost | html div: [html heading: eachPost title level: 2; text: eachPost body. html div: [html bold: 'Comments'. eachPost comments do: [:eachComment | html heading: eachComment name level: 4; text: eachComment comment]]]]. html anchor on: #newPost of: self

1. Add a method:

newPost | post |post := self call: (BlogPost new asComponent addValidatedForm; yourself ). post ifNotNil: [BlogPost repository add: post]

1. Back in your browser:
   
   1. Refresh your browser and add a new post (making some sample mistakes along the way). Click Save.
   2. Whoops! We have an error. Click the link for Debug and the debugger opens in Squeak.
   3. We can see where the problem is, so close the debugger and go to BlogPost’s comments method, and change the body to “ ^comments ifNil: [comments := OrderedCollection new]”
   4. Refresh your browser and view your new post.
   5. Try and create a posting with the same title. Can’t do that! Change the title and save it.
2. Select BlogView, renderContentOn, and make it look like this:

renderContentOn: html BlogPost repository reversed do: [:eachPost | html div: [html heading: eachPost title level: 2; text: eachPost body. html div: [html bold: 'Comments'. eachPost comments do: [:eachComment | html heading: eachComment name level: 4; text: eachComment comment]]. (html anchor) callback:[self addCommentTo: eachPost]; text: 'Add Comment']].

1. Back to your browser:
   
   1. Refresh
2. Create addCommentTo:

addCommentTo: aPost

| comment |

comment := self call: (BlogComment new asComponent addValidatedForm ; yourself).

comment ifNotNil: [aPost comments add: comment]

1. Create a new method category named actions, and move addCommentTo and newPost into it.
2. Back to your browser
   
   1. New session
   2. Add a comment and save it.
   3. Add a second comment and save it.
   4. Add and save one final posting.
   5. Turn halos on. Click on S for source.
   6. Click on configure and set it to deployment mode.
   7. With a new session, no more development tools available.