Play Framework full implementation of one app (eight)

Create tag Tag

1. Create model

@Entity @table (name="Blog_tag") Public classTag extends Model implements Comparable<tag> {      PublicString name; PrivateTag (String name) { This. Name =name; }         PublicString toString () {returnname; }         Public intcompareTo (Tag othertag) {returnName.compareto (othertag.name); }      Public Statictag Findorcreatebyname (String name) {tag tag= Tag.find ("byname", name). First (); if(Tag = =NULL) {tag=NewTag (name); }        returntag; }}

2.Post Class Add Tag Property

@ManyToMany (cascade =cascadetype.persist) PublicSet<tag>tags; PublicPost (User author, string title, string content) { This. Comments =NewArraylist<comment>();  This. tags =NewTreeset<tag>();  This. Author =author;  This. title =title;  This. Content =content;  This. Postedat =NewDate ();}

　

3.Post class Add method

Associating Post and tag

 Public Post Tagitwith (String name) {        Tags.add (tag.findorcreatebyname (name));         return  This ;}

　　

Returns the Post collection associated with the specified tag

 Public Static List<post> findtaggedwith (String ... tags) {        return  post.find (                "Select Distinct p from Post p joins p.tags as T where T.name in (: Tags) group by p.id, P.author, p.title, p.content,p.postedat hav ing count (t.id) =: Size "        ). Bind (" tags ", tags). bind (" Size ", tags.length). Fetch ();

4. Write Test Cases

@Test Public voidtesttags () {//Create A new user and save itUser Bob =NewUser ("[Email protected]", "secret", "Bob"). Save (); //Create a new postPost Bobpost =NewPost (Bob, "My first post", "Hello World"). Save (); Post Anotherbobpost=NewPost (Bob, "Hop", "Hello World"). Save (); // WellAssertequals (0, Post.findtaggedwith ("Red"). Size ()); //Tag It nowBobpost.tagitwith ("Red"). Tagitwith ("Blue")). Save (); Anotherbobpost.tagitwith ("Red"). Tagitwith ("Green")). Save (); //CheckAssertequals (1, Post.findtaggedwith ("Red", "Blue"). Size ()); Assertequals (1, Post.findtaggedwith ("Red", "Green"). Size ()); Assertequals (0, Post.findtaggedwith ("Red", "Green", "Blue"). Size ()); Assertequals (0, Post.findtaggedwith ("Green", "Blue"). Size ());   }

Test tag

5. Continue to modify the tag class and add methods

 Public Static List<map> Getcloud () {        List<Map> result = Tag.find (            "select New Map (T.name as Tag , Count (p.id) as pound) from the Post p join P.tags as T GROUP by T.name ORDER by T.name "        ). Fetch ()        ; return result;}

6. Add tag to the page

/yabe/conf/initial-data.yml Adding preset data

Tag (play):    name:           play Tag (architecture):    Name:           architecture Tag (test):    name:           Test Tag (MVC ):    name:           MVC Post (jeffpost):    title: The          MVC application    postedat:       2009-06-06    Author:         Jeff    Tags:                               -play                    -Architecture                    -MVC    content:        >                    A Play

　　

7. Modify display.html to display the tag

<div class= "Post-metadata" >        <span class= "Post-author" >by ${_post.author.fullname}</span>        <span class= "post-date" >${_post.postedat.format (' dd MMM yy ')}</span>    #{if _as! = ' Full '}<  Span class= "Post-comments" > | ${_post.comments.size ()?: ' No '} comment${_post.comments.size (). Pluralize ()} #{if _post.comments}  , latest by ${_ Post.comments[0].author} #{/if}</span>#{/if}#{elseif _post.tags}<span class= "post-tags" >-Tagged #{list Items:_post.tags, as: ' Tag '}<a href= "#" >${tag}</a>${tag_islast? ': ', '}#{/list}</span>#{/elseif}     </div>

　　

8. Add listtagged method (Application Controller)

Click Tagged to display all the post lists with tags

 Public Static void listtagged (String tag) {    List<Post> posts = Post.findtaggedwith (tag);    Render (tag, posts);}

9. Modify Display.html,tag Display

-Tagged #{list items:_post.tags, as: ' Tag '}    <a href= "@{application.listtagged (Tag.name)}" >${tag}</a >${tag_islast? ': ', '}#{/list}

　　

10. Add route

GET     /posts/{tag}                    application.listtagged

　　

There are now two route rule URLs that cannot be distinguished

GET     /posts/{id}                             application.showget     /posts/{tag}                    application.listtagged

Add a rule for {ID}

GET     /posts/{<[0-9]+>id}             application.show

　　

11. Add the Post list page with the same tag post

Create /app/views/application/listtagged.html

#{extends ' main.html '/}#{set title: ' Posts tagged with ' + tag/}*{********* title *********}*#{if posts.size () >1}< H3>there ${posts.size ()} posts tagged ${tag}
　　
Effect:
　　
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Play Framework full implementation of one app (eight)