/EntityFramework/Beta3/MyTravel_WCF_Sample/ObjectServices_MyTravel_CS/MyTravelPostWebsite/TravelPage.aspx.cs

// Copyright (c) Microsoft Corporation.  All rights reserved.



using System;

using System.Data;

using System.Configuration;

using System.Collections;

using System.Linq;

using System.Web;

using System.Web.Security;

using System.Web.UI;

using System.Web.UI.WebControls;

using System.Web.UI.WebControls.WebParts;

using System.Web.UI.HtmlControls;

using System.Xml.Linq;



using MyTravelPostWebsite.MyTravelPostService;

using System.Collections.Generic;



namespace MyTravelPostWebsite

{

    public partial class TravelPage : System.Web.UI.Page

    {

        protected void Page_Load(object sender, EventArgs e)

        {

            // check the post back

            if (IsPostBack)

            {

                return;

            }



            // get the blog id from the page request.

            int blogID = 0;

            int.TryParse(Request.Params["BlogID"], out blogID);



            // create a short lived service and request for latest blog post

            using (MyTravelPostServiceClient travelEntitiesService = new MyTravelPostServiceClient())

            {

                Blog blog = travelEntitiesService.GetBlog(blogID);

                BlogPost post = travelEntitiesService.GetLatestBlogPosting(blog);



                if (null != post)

                {

                    // fill in the new text.

                    labelBlogTitle.Text = post.BlogTitle;

                    labelSeries.Text = blog.SeriesTitle;

                    labelPerson.Text = blog.BlogWriter.Name;

                    blogEntry.Text = post.BlogEntry;



                    // call the methods to update the comments.

                    UpdateCommentsList(post);



                    var people = travelEntitiesService.GetPeople();



                    // not set all the people in the dropdown list

                    dropdownPersons.DataTextField = "Name";

                    dropdownPersons.DataSource = people;

                    dropdownPersons.DataBind();



                    dropdownBlogPersonChange.DataTextField = "Name";

                    dropdownBlogPersonChange.DataSource = people;

                    dropdownBlogPersonChange.DataBind();                    



                    // setup the viewstate that we need in the submit button

                    ViewState["BlogPost"] = post;

                    ViewState["People"] = people;

                    ViewState["Blog"] = blog;

                }

            }

        }



        // on submit, we need to add a comment that's associated to the blog post.

        protected void buttonSubmitComment_Click(object sender, EventArgs e)

        {

            // create a short lived service and send back the travel blogs.

            using (MyTravelPostServiceClient travelEntitiesService = new MyTravelPostServiceClient())

            {

                BlogPost post = (BlogPost)ViewState["BlogPost"];

                List<Person> peopleList = (List<Person>)ViewState["People"];



                // get the person from the people list

                Person person = peopleList[dropdownPersons.SelectedIndex];



                Comment newComment = new Comment();

                newComment.CommentText = textComment.Text;

                

                // what we are doing here is setting up the relationships, similar

                // to a foriegn key. If you didn't have the EntityKey on the reference

                // then you would have to send all the related ends.

                // this case we can optimize and build the relationships

                // and send them down to be added in the ObjectContext.

                newComment.PersonReference = new EntityReferenceOfPersonXC1u02lO();

                newComment.PersonReference.EntityKey = person.EntityKey;

                newComment.BlogPostReference = new EntityReferenceOfBlogPostXC1u02lO();

                newComment.BlogPostReference.EntityKey = post.EntityKey;



                // call the service that adds the comment to the database.

                newComment = travelEntitiesService.AddComment(newComment);



                newComment.CommentWriter = person;



                // add to the overall list of comments, and update the post.

                post.PostComments.Add(newComment);



                // clear the text.

                textComment.Text = "";

                    

                // call the methods to update the comments on the field

                UpdateCommentsList(post);



                // reload page so that F5, refresh doesn't update all this data.

                ReloadPage();

            }

        }



        private void ReloadPage()

        {

            // get the blog and reload this page so that refresh won't give us

            // bad data.

            Blog blog = (Blog)ViewState["Blog"];



            // launch this page again.

            Response.Redirect("TravelPage.aspx?BlogID=" + blog.BlogID);

        }



        private void UpdateCommentsList(BlogPost post)

        {

            // get all the comments with people and load the comments grid.

            var comments = from c in post.PostComments

                           select new

                           {

                               Author = c.CommentWriter.Name,

                               WhatISaid = c.CommentText,

                           };



            // reset the blog post into comments.

            ViewState["BlogPost"] = post;

            gridComments.DataSource = comments;

            gridComments.DataBind();

        }



        protected void gridComments_RowDeleted(object sender, GridViewDeletedEventArgs e)

        {

            // we did all the work in RowDeleting

        }



        protected void gridComments_RowDeleting(object sender, GridViewDeleteEventArgs e)

        {

            // create a short lived service and send back the travel blogs.

            using (MyTravelPostServiceClient travelEntitiesService = new MyTravelPostServiceClient())

            {

                // get the comment that is being marked for deletion

                // and get the view state blog post.

                BlogPost post = (BlogPost)ViewState["BlogPost"];

                

                // move the comment to the deleted comment selection.                

                Comment deletedComment = post.PostComments[e.RowIndex];

                

                // remove the post comment from the deleted item.

                post.PostComments.RemoveAt(e.RowIndex);



                // serialize the post and the deleted comments back to view state.

                ViewState["BlogPost"] = post;



                // call the DeleteComment service

                travelEntitiesService.DeleteComment(deletedComment);

                

                // update the comments

                UpdateCommentsList(post);

                

                // reload page so that F5, refresh doesn't update all this data.

                ReloadPage();            

            }

        }



        protected void buttonUpdate_Click(object sender, EventArgs e)

        {

            // create the update service

            using (MyTravelPostServiceClient travelEntitiesService = new MyTravelPostServiceClient())

            {

                // here we are going to take every other comment and put (*) at the end.

                // this is just to show how to make the web service call and update

                // items on the other end.

                BlogPost post = (BlogPost)ViewState["BlogPost"];

                List<Comment> updatedComments = new List<Comment>();



                // this bool value is so we can pass in a subset of items to updated.

                bool toupdate = true;

                foreach (Comment c in post.PostComments)

                {

                    if (toupdate)

                    {

                        // create a new comment and just set the id and entity key

                        // that's all we need to update the new comment text.

                        Comment newComment = new Comment();

                        newComment.EntityKey = c.EntityKey;

                        newComment.CommentID = c.CommentID;

                        newComment.CommentText = c.CommentText + "*";

                        

                        updatedComments.Add(newComment);

                        toupdate = false;

                    }

                    else

                    {

                        toupdate = true;

                    }

                }



                // even through the comments are also attached to the post

                // we can drop and just send the updated items. This helps in 

                // reducing the amount of data going through the service.

                post.PostComments 

                    = travelEntitiesService.UpdateComments(post.PostComments, updatedComments);



                // update the view state, and be sure to update the gridview

                ViewState["BlogPost"] = post;

                UpdateCommentsList(post);



                // reload page so that F5, refresh doesn't update all this data.

                ReloadPage();

            }

        }



        protected void ChangeOwner_Click(object sender, EventArgs e)

        {

            // create the update service

            using (MyTravelPostServiceClient travelEntitiesService = new MyTravelPostServiceClient())

            {

                // here we are going to take every other comment and put (*) at the end.

                // this is just to show how to make the web service call and update

                // items on the other end.

                Blog blog = (Blog)ViewState["Blog"];

                

                // get the person from the people list

                List<Person> peopleList = (List<Person>)ViewState["People"];

                Person person = peopleList[dropdownBlogPersonChange.SelectedIndex];

                EntityKey personKey = person.EntityKey;



                // use the key from the person to change the ownship of this blog

                travelEntitiesService.ChangeBlogowner(blog, personKey);



                // reload page so that F5, refresh doesn't update all this data.

                ReloadPage();

            }

        }

    }

}