How To Create A Blog In Ruby In Steel (On Rails)

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 11http://localhost:3003/Blog/indexHowever, the index method is special. It is treated as the default method andso its name may be omitted like this:http://localhost:3003/BlogEither way, the code in the index method is executed:def indexrender :text "Hello World!"endHere the BlogController class is a descendent of ApplicationController and it usesthe render method of the ApplicationController class. Ruby programmers willrecognise that the symbol :text forms the key part of a Hash item in which“Hello world!” is the value. The above code could be rewritten thus:def indexrender( {:text "Hello World!"} )end5. Create A templateDo ThisRight-click app/views/blog directory in the Solution Explorer.From the popup menu, select Add then New Item.Pick the empty rhtml ItemIn the Name field of the dialog, name the file index.rhtmlClick Add

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 12Right-click the Solution Explorer to add a new itemIn this file (index.rhtml) enter this plain text:hello from the templateSave the file.Go to Web Browser and refresh.This now shows “hello from the template”What HappensThe index.rhtml file defines the default ‘view template’. When no indexmethod is defined in the Blog controller, Rails goes to the index.rhtml templateto look for anything to be included in the HTML page which will be displayedin the browser.

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 13CommentaryHere we’ve entered plain text into the template. We could just as well haveentered any valid HTML. For example, if we wanted “Hello” to be shown inbold text and “Sapphire In Steel” to be displayed as a hyperlink leading towww.sapphiresteel.com, this is what we would enter: b Hello /b from a href "http://www.sapphiresteel.com" Sapphire In Steel /a Rails incorporates this fragment of HTML code into a fully formed HTMLpage which is then sent back to the browser.Once again, index, forms an optional part of the URL which must be enteredin order to display this page. Either of the following URLs will ost:3003/BlogIf, on the other hand, you had called your rhtml file myview.rhtml, you wouldneed to enter this URL:http://localhost:3003/Blog/myview6 & 7 (There is No Step 6 or 7)In the original Rails Blog demo you would now have to enter databaseconfiguration details into the config.yml file. You would then have to create aMySQL database as a separate operation. Ruby In Steel did all that for youwhen you first created your project so you can sit back and have a cup of teaat this stage ;-)8. Create tablesDo Thisa) In MySQLIf you are already familiar with MySQL, use your usual method of creatingthe column definitions in this step. If not, we suggest you use a simple frontend such as SQLYog (http://www.webyog.com/).

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 14Using SQLYog.Create columns as follows:idtitleint 11Not Null yes,varchar 255auto-incrementRight-click: create tableClick Create table buttonEnter postsSaveb) In SQL ServerIf the Server Explorer is not visible in Ruby In Steel, press CTRL W, L toshow it. Right-click Data Connections. Select Add Connection. If MicrosoftSQLServer (SqlClient) is not shown as Data Source, click the Change buttonand select Microsoft SQL Server. Then click OK.In the Add Connection dialog, enter the server name (which you should havespecified when installing SQLServer and starting this Rails application): e.g.\SQLEXPRESSSelect Use SQL Server Authentication.Enter your user name and password for SQL Server. Once again, you need tohave set these up earlier. In the Demo movie, I enter (name) huw(password) huwSelect the database name from a drop down list(e.g. MyBlog development).Click Test Connection.All being well, click OK. (If you have errors, you will need to check theinstallation, name, password details etc. of SQLServer).

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 15Use the Server Explorer to work with a SQLServer databaseClick the database in Server Explorer to open its branches.Right-click the Tables branch.Select Add New TableYou will see a database grid labelled:Column Type Data Type Allow NullsEnter two rows into these columns as follows:Column Typeidtitle Data Type intvarchar(255)Allow Nulls(NOT Selected)Use integrated table editing with SQL ServerRight-click the id row and select Set As Primary keyIn Table Designer Properties panel set Identity Column as id (this causes autoincrement).

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 16Press CTRL S to save table. Enter the name ‘Posts’Click OKWhat HappensThis step sets up a database called MyBlog, creates a table called posts anddefines two columns – or data ‘fields’ – a unique id field and a text field foreach Blog entry.CommentaryYou will either need MySQL or SQL Server installed. MySQL is free. Microsofthas a free edition of SQL Server called SQL Server Management StudioExpress To use Rails with SQLServer you will also need to install the fileADO.rb (refer to the requirements and notes given at the start of this document).Currently, SQL Server integrates more fully into Visual Studio, so that you cancreate your data table definitions in the VS 2005 environment. A moreintegrated version of MySQL is under development however.9. Generate ModelDo ThisClick Rails menu. Select Generate.In the Generate dialog, select ModelIn value field enter: PostClick OKView Solution ExplorerThe file post.rb is added to app/models branch of the Solution ExplorerWhat HappensWe have run a Rails script to create a ‘model’ for posts. A model is used tointerface with data in the database. Here the post model will interface withthe posts table.CommentaryBy now it should be no surprise that the Post model is generated using adialog box rather than running a script and that the Solution Explorer issynchronized automatically to show the newly generated file.

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 1710. Use ScaffoldDo ThisDouble-click Blog controller.rbEdit it to this by adding (just beneath class BlogController ApplicationController), the following:scaffold :postSaveGo back to Web browser and refresh.What HappensHere scaffold is a method of the Rails ActionController class (from which theparent class of our BlogController (that is, ApplicationController) descends. Thescaffold method adds various database access routines to the controller; ituses the specified symbol (:post) to create an instance variable with a similarname, (here @post) and also identify the model class (Post) to use.CommentaryScaffolding is a simple way of creating the basic skeleton of an applicationusing a model. It provides access to routines to show and edit data in a webbrowser. In Rails, this is the simplest way of displaying and interacting with adatabase via a browser.11. Create, show and edit a new postDo ThisIn the browser.click the New Post linkEnter some text: e.g. “Hello East Grinstead!”Click CreateClick ShowClick EditAlter text: e.g. “Goodbye East Grinstead!”

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 18Click UpdateWhat HappensWe have now entered and edited our first record into the Posts table of theBlog database.CommentaryThe editing and updating features have been provided by the Rails scaffoldwhich links the Post model to the Posts table. Each Every time we create anew post it is entered as a row in the Posts table. The scaffold provides theHTML elements required to display and edit posts in a web browser.12. Add more database columnsDo This(NOTE: From now on, these instructions assume you are using SQL Server. Ifyou are using MySQL you will need to manipulate the database tables andrecords using whichever tools you used in Step 8 .)In Visual Studio In the Posts table editor tabadd new column:column name data typebodytextSave (press Ctrl S)In the Web Browser.Click Edit (to show the body )In the text field, enter some text such as.Hello, hello, hello.Click UpdateIn Visual Studio .In the Posts table editing tab .

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 19Insert a new field ABOVE body field (i.e. right click body and select ‘InsertColumn’). Add.Column name created atData TypedatetimeSaveIn Web Browser Click Edit to edit a post.Change the date by picking a new data from the combo list.Click UpdateWhat HappensYou have modified the database by adding new columns and the changeshave propagated through to the view in the browser.CommentaryCurrently table editing from within Visual Studio itself is only supported forMS SQL Server. MySQL has announced plans to integrated with VisualStudio, however, and when this is done it should be possible to implement asimilar feature for MySQL databases. We shall be adding a broader range ofdatabase support to subsequent versions of Steel but in many cases it may benecessary to use a standalone tool to create or manipulate the databasestructure.13. Add ValidationDo ThisIn Visual Studio Using the Solution Explorer Open models/post.rbadd (just after : class Post ActiveRecord::Base )validates presence of :title

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 20SaveIn Web Browser.Click Back (if necessary) to get back to List viewClick New Post.Click Create (i.e. try to add new post with blank title)The Browser shows error message.Add some text to the Title and Body fields: e.g.Title: My Lovely TitleBody: Ah, that’s better Click CreateWhat HappensYou have added validation to the title field to prevent the user entering ablank title. If a blank is entered an error message will be shown in thebrowser.CommentaryHere, validates presence of is a method of the Rails ActiveRecord class. Itchecks if a named attribute of an object (which corresponds to a databaserecord) is blank. The name is specified using a Ruby symbol such as :title.14. Generate ScaffoldDo ThisIn Visual Studio Click the Generate icon (or select Generate from the Rails menu).In the Generate dialog select ScaffoldEnter value: Post BlogClick OKIf blog controller.rb is still open you will be shown a message that it has beenchanged outside of Visual Studio and asked if you want to reload it – click‘Yes To All’)

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 21View blog controller.rb to show all the actions that have been added.What HappensThe Scaffold script generates a whole load of code ‘actions’ and template pagesto create, show and view posts in simple layout inside a web browser.CommentaryOnce again, this is all done using a Ruby In Steel dialog box instead of havingto use a command prompt. Notice that the template (RHTML) files are nowavailable beneath the \views\blog directory in the Solution Explorer.15. Edit templateDo ThisOpen \view\blog\list.rhtml in Solution ExplorerChange: h1 Listing posts /h1 To: h1 My Wonderful Weblog /h1 Delete all the rest of the file.Cut and paste the following: % for post in @posts % div h2 % link to post.title, :action 'show', :id post % /h2 p % post.body % /p p small % post.created at.to s % /small /p /div % end % % link to 'Previous page', { :page @post pages.current.previous } if @post pages.current.previous% % link to 'Next page', { :page @post pages.current.next }if @post pages.current.next % br / % link to 'New post', :action 'new' %

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 22SaveGo back to Web Browser and refreshIn Visual Studio In list.rhtml edit first line to the following: (i.e. add .reverse) % for post in @posts.reverse % SaveRefresh browserWhat HappensHere we have added some Ruby code embedded in a Rails RHTML template.The Ruby code displays the data of each post which it finds in the databasewe created earlier. It also adds links to help us navigate in the web browserview and to add a new post.CommentaryThe created at method which we used above (post.created at) was generatedby Rails to match the created at database column which we added earlier.The variable @posts is an array of Post objects and the reverse method is astandard Ruby method to reverse the array.Here we are creating templates for various bits of a complete HTML page. TheHTML contains Ruby programming code inside ares delimited by % or % and % . The page itself will be constructed by Rails and sent to the browser tobe displayed when a user navigates to that view (for example, as a result ofclick a button or hyperlink). By the time the page appears in the browser theRuby code will have been stripped out and replaced with valid HTML such astext or data extracted from the database.Notice that Steel automatically colour codes RHTML files and implementscode collapsing to let you hide blocks of HTML code such as DIVs andparagraphs.

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 2316. Use Textile Text FormattingDo ThisIn Web Browser Click a message header (e.g. ‘My Lovely Title’)Edit message to show Textile markup Click the Edit linkIn the body enter:*Hello* worldClick EditClick Back (i.e. make sure the blog/list view is shown in the browser)In Visual Studio In list.rhtml.edit first p line (probably this will be on line 6 or thereabouts) to: p % textilize(post.body) % /p SaveIn Web Browser refresh to show bold and italic.What HappensWe have used some Textile formatting commands * and * for bold and andfor italic then applied these in the list view using the textilize method inlist.rhtmlCommentaryThis requires the installation of an add-on package called RedCloth. If youhaven't already got this installed you can install this using the Ruby In SteelGem dialog. This is how that is done. From the Rails menu select Gems then,when the dialog appears, enter:redcloth --version "3.0.4"You need to be online to retrieve a Gem like this. All being well, the gem willbe downloaded and installed. The equivalent way of installing this Gem fromthe command prompt would be:gem install redcloth --version "3.0.4"

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 2417. Customise ViewDo ThisIn Visual Studio In blog controller.rb Delete code of the list method and edit it to this:def listend@posts Post.find(:all)SaveIn list.rhtmlDelete this line (probably on line 3). % for post in @posts.reverse % .and the matching % end % (probably on line 10 or 11).Then cut this. div h2 % link to post.title, :action 'show', :id post% /h2 p % textilize(post.body) % /p p small % post.created at.to s % % post.class % /small /p /div Save list.rhtmlRight-click \views\Blog and select Add, New ItemPick empty rhtmlName to: post.rhtmlClick AddNow paste the code (that we just cut from list.rhtml) into into post.rhtmlSave

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 25In list.rhtml Delete all but first and last line. Add this: % render :partial "post", :collection @posts.reverse% (Check this: The code in list.rhtml should now be as follows: h1 My Wonderful Weblog /h1 % render :partial "post", :collection @posts.reverse% % link to 'New post', :action 'new' % SaveLoad show.rhtmlDelete this. % for column in Post.content columns % p b % column.human name % : /b % h@post.send(column.name) % /p % end % Add this: % render :partial "post", :object @post % SaveIn Web Browser (Make sure you are in the list view showing more than one post) Click an item header (e.g. ‘My Lovely Title’)Note, the Show view (in which just one post is shown) now uses thepost.rhtml templateWhat HappensA view is the web page representation of your application and the user’sinterface to your data. Here the list and show templates are changed; the view

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 26of an individual post has been cut out of the list view definition and put intoits own file. This means that it is available to be used in another view – onother web pages – if we so wish. But the post.rhtml view is incomplete – itdoesn't form a workable html page. So the blog controller.rb Ruby file has to betold that the “post” view is only part of a complete view.CommentaryThe magic that goes on here can be summarized in this line: % render :partial "post", :object @post % Here render is the name of a Rails method. When passed the symbol :partial,it knows that it only needs to update a specified part of a page. Here the“post” view is specified.In this example, the partial template for a post is used in both the list and theshow page templates.18. Add CommentsDo ThisIn Visual Studio To Generate the Comment model Click the Generate IconSelect ModelEnter as Value:CommentClick OKIn VS Solution Explorer Open models/comment.rbEdit method to class Comment ActiveRecord::Basebelongs to :postendSave

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 27Open models/post.rbEdit to:class Post ActiveRecord::Basevalidates presence of :titlehas many :commentsendSaveWhat HappensWe generate a Comment model and edit its ruby file, comment.rb, toassociate Comment with post.CommentaryThe Rails ActiveRecord belongs to method is passed a symbol identifying thetype of object to which comments belong. The has many method followed bythe :comments symbol, tells the Post class that each Post may have manyassociated Comment objects.19. Create Comments Table and Display CommentsDo ThisIn Visual Studio.Switch to Server ExplorerFind the Tables branch of databaseRight-click.Select Add New TableAdd these columns.Column Nameidbodypost iddata TypeinttextintAllow NullsAllow Nulls NOT SelectedAllow Nulls NOT SelectedRight-click id and select Set As Primary keyIn Table Designer Properties panel set Identity Column as id (this causes autoincrement).Press CTRL S to save table. Enter the name ‘Comments’

www.sapphiresteel.com – Ruby In Steel (on Rails) weblog page 28Click OKTo enter some data .Right-click Comments table in Server ExplorerSelect: Show table DataIn Table Data display add a comment (NULL) / That’s very interesting! / 1Press Enter to go to next line (wh

Usually in Rails when you want to start the server you have to open a command prompt and enter a command such as this: ruby ./script/server –p3003 Here the optional final parameter is the port on which the server runs. In Ruby In Steel you can run the server using the Rails menu. Rails applications can also use other servers, such as Apache.