第六章主要讲解使用controller实现页面之间的跳转。在系统中实现了Post信息提交及显示功能。主要的知识点有：

• 访问路径控制:
• addPost方法:timeline页面的form将表单提交给addPost方法,addPost方法返回
• .操作符:list.prop
• ?:操作符:表达式?如果true:如果false
• ${flash.massage}
• spock单元测试:controller页面重定向测试
• spock单元测试:@spock.lang.Unroll
• spock单元测试:"Testing id of #suppliedId redirects to #expectedUrl"
• spock集成测试

默认访问index,重定向给timeline/params,如果没有params,默认给一个.

    ......def index() {    if (!params.id)         params.id = "jeff"        redirect action: 'timeline', params: params    }def timeline() {    def user = User.findByLoginId(params.id)    if (!user) {        response.sendError(404)    } else {        [ user : user ]    }}......

增加一个post,因为post需要指定user,所以需要user登录,前面的index指定了一个user params,可以直接使用.后续增加登录功能

    ......def addPost() {    def user = User.findByLoginId(params.id)    if (user) {        def post = new Post(params)        user.addToPosts(post)        if (user.save()) {            flash.message = "Successfully created Post"        } else {            flash.message = "Invalid or empty post"        }    } else {        flash.message = "Invalid User Id"    }    redirect(action: 'timeline', id: params.id)}......

访问index,重定向给timeline,timeline.gsp负责提交post并显示post信息,所以,timeline分这两个部分.

                        
                    
    
            
     
                What is ${ user.profile ? user.profile.fullName : user.loginId } hacking on right now?            
            
                     
      
       ${flash.message}
      
            
                 <@!-- 提交(addPost) -->            
     
                
                          
       
       
                    
                       
                  
        
    
        <@!-- 显示(timeline/params) -->        
    
            
                     
      
                    
       
        ${post.content}
       
                    
       
        ${post.dateCreated}
       
                
      
            
             
    
    

这本书在测试上下了一些功夫,讲解的也很到位. 单元测试:test/unit/com.grailsinaction.PostControllerSpec.groovy

    package com.grailsinactionimport grails.test.mixin.Mockimport grails.test.mixin.TestForimport spock.lang.Specification@TestFor(PostController)@Mock([User,Post])class PostControllerSpec extends Specification {    def "Get a users timeline given their id"() {        given: "A user with posts in the db"            User chuck = new User(loginId: "chuck_norris", password: "password").save(failOnError: true)            chuck.addToPosts(new Post(content: "A first post"))            chuck.addToPosts(new Post(content: "A second post"))        and: "A loginId parameter"            params.id = chuck.loginId        when: "the timeline is invoked"            def model = controller.timeline()        then: "the user is in the returned model"            model.user.loginId == "chuck_norris"            model.user.posts.size() == 2    }    def "Check that non-existent users are handled with an error"() {        given: "the id of a non-existent user"            params.id = "this-user-id-does-not-exist"        when: "the timeline is invoked"            controller.timeline()        then: "a 404 is sent to the browser"            response.status == 404    }    def "Adding a valid new post to the timeline"() {        given: "A user with posts in the db"            User chuck = new User(loginId: "chuck_norris", password: "password").save(failOnError: true)        and: "A loginId parameter"            params.id = chuck.loginId        and: "Some content for the post"            params.content = "Chuck Norris can unit test entire applications with a single assert."        when: "addPost is invoked"            def model = controller.addPost()        then: "our flash message and redirect confirms the success"            flash.message == "Successfully created Post"            response.redirectedUrl == "/post/timeline/${chuck.loginId}"            Post.countByUser(chuck) == 1    }    def "Adding a invalid new post to the timeline trips an error"() {        given: "A user with posts in the db"            User chuck = new User(loginId: "chuck_norris", password: "password").save(failOnError: true)        and: "A loginId parameter"            params.id = chuck.loginId        and: "Some content for the post"            params.content = null        when: "addPost is invoked"            def model = controller.addPost()        then: "our flash message and redirect confirms the success"            flash.message == "Invalid or empty post"            response.redirectedUrl == "/post/timeline/${chuck.loginId}"            Post.countByUser(chuck) == 0    }    @spock.lang.Unroll    def "Testing id of #suppliedId redirects to #expectedUrl"() {        given:            params.id = suppliedId        when: "Controller is invoked"            controller.index()        then:            response.redirectedUrl == expectedUrl        where:            suppliedId | expectedUrl            'joe_cool' | '/post/timeline/joe_cool'            null | '/post/timeline/chuck_norris'    }}

集成测试:test/integration/com.grailsinaction.PostIntegrationSpec.groovy

    package com.grailsinactionimport grails.plugin.spock.IntegrationSpecclass PostIntegrationSpec extends IntegrationSpec {		def "Adding posts to user links post to user"() {		given: "A brand new user"			def user = new User(loginId: 'joe',				password: 'secret').save(failOnError: true)		when: "Several posts are added to the user"			user.addToPosts(new Post(content: "First post... W00t!"))			user.addToPosts(new Post(content: "Second post..."))			user.addToPosts(new Post(content: "Third post..."))		then: "The user has a list of posts attached"			3 == User.get(user.id).posts.size()	}	def "Ensure posts linked to a user can be retrieved"() {		given: "A user with several posts"			def user = new User(loginId: 'joe', password: 'secret').save(failOnError: true)			user.addToPosts(new Post(content: "First"))			user.addToPosts(new Post(content: "Second"))			user.addToPosts(new Post(content: "Third"))		when: "The user is retrieved by their id"			def foundUser = User.get(user.id)			List
    
      sortedPostContent = foundUser.posts.collect { it.content }.sort()		then: "The posts appear on the retrieved user"			sortedPostContent == ['First', 'Second', 'Third']	}	def "Exercise tagging several posts with various tags"() {		given: "A user with a set of tags"			def user = new User(loginId: 'joe', password: 'secret').save(failOnError: true)			def tagGroovy = new Tag(name: 'groovy')			def tagGrails = new Tag(name: 'grails')			user.addToTags(tagGroovy)			user.addToTags(tagGrails)		when: "The user tags two fresh posts"			def groovyPost = new Post(content: "A groovy post")			user.addToPosts(groovyPost)			groovyPost.addToTags(tagGroovy)			def bothPost = new Post(content: "A groovy and grails post")			user.addToPosts(bothPost)			bothPost.addToTags(tagGroovy)			bothPost.addToTags(tagGrails)		then:			user.tags*.name.sort() == ['grails', 'groovy']			1 == groovyPost.tags.size()			2 == bothPost.tags.size()	}}