public async Task <ActionResult> EditPost(int?id, byte[] rowVersion)
{
#region Bad Request (null) Check
if (id == null)
{
return(new HttpStatusCodeResult(HttpStatusCode.BadRequest));
}
#endregion
#region Properties
string [] fieldsToBind = { "Title", "Subtitle", "Body", "ModifiedOn", "RowVersion", "CommentId", "TagId", "UserId" };
Blogpost blogpostToUpdate = await _blogpostRepository.GetBlogpostById(id);
byte[] rowVersionException = null;
int? tagIdException = null;
#endregion
if (blogpostToUpdate == null)
{
Blogpost deletedBlogpost = new Blogpost();
TryUpdateModel(deletedBlogpost, fieldsToBind);
ModelState.AddModelError(string.Empty, "Unable to save changes. The Blogpost was deleted by another user.");
return(View("~/Views/Blogpost/Edit.cshtml", deletedBlogpost));
}
if (TryUpdateModel(blogpostToUpdate, fieldsToBind))
{
try {
await _blogpostRepository.SetRowVersion(blogpostToUpdate, rowVersion);
return(RedirectToAction("Index"));
}
#region UpdateConcurrency Catch
catch (DbUpdateConcurrencyException ex) {
// 3 lines below get both the values read from the DB and the new values entered by the user
DbEntityEntry entry = ex.Entries.Single();
Blogpost clientValues = (Blogpost)entry.Entity;
DbPropertyValues databaseEntry = entry.GetDatabaseValuesAsync().Result;
if (databaseEntry == null)
{
ModelState.AddModelError(string.Empty,
"Unable to save changes. The Blogpost was deleted by another user.");
}
else
{
Blogpost databaseValues = (Blogpost)entry.GetDatabaseValuesAsync().Result.ToObject();
// TODO: Make sure that the current logged on user gets inserted into the DB as the editor and the creator does not get changed
/*
* All if statements give custom error messages for each column that has DB values different from
* what the user entered on the Edit page. The last if statement compares the TagId for that blogpost
* and then gets the tags 'Name'
*/
if (databaseValues.Title != clientValues.Title)
{
ModelState.AddModelError("Title", "Current value: " + databaseValues.Title);
}
if (databaseValues.Subtitle != clientValues.Subtitle)
{
ModelState.AddModelError("Subtitle", "Current value: " + databaseValues.Subtitle);
}
if (databaseValues.Body != clientValues.Body)
{
ModelState.AddModelError("Body", "Current value: " + databaseValues.Body);
}
if (databaseValues.TagId != clientValues.TagId)
{
// This captures the databaseValues' TagId so it can be saved below (must be done outside this catch since it needs to be awaited)
tagIdException = databaseValues.TagId;
}
ModelState.AddModelError(string.Empty,
"The record you attempted to edit was modified by another user "
+ "after you got the original value. The edit operation was canceled and the current values in the "
+ "database have been displayed. If you still want to edit this record, and overwrite the other "
+ "user's changes, click the 'Save' button again. Otherwise click the 'Back to List' hyperlink.");
// This captures the databaseValues' RowVersion so it can be saved below (must be done outside this catch since it needs to be awaited)
rowVersionException = databaseValues.RowVersion;
}
}
#endregion
#region RetryLimitExceeded Catch
// Creating new catch for the connection resiliency stuff and the BlogConfiguration.cs class
catch (RetryLimitExceededException /* dex */) {
// TODO: Log the error (uncomment dex variable name and add a line here to write a log
ModelState.AddModelError(string.Empty, "Unable to save changes. Try again and, if the problem persists, see the system administrator.");
}
#endregion
}
// This sets the 'TagId' of the Blogpost object to the new value retrieved from the DB, only if the rowVersionException variable was filled
if (tagIdException != null)
{
ModelState.AddModelError("TagId", "Current value: " + (await _tagRepository.GetTagById(tagIdException)).Name);
}
// This sets the 'RowVersion' of the Blogpost object to the new value retrieved from the DB, only if the rowVersionException variable was filled
if (rowVersionException != null)
{
await _blogpostRepository.SetRowVersion(blogpostToUpdate, rowVersionException);
}
await PopulateTagsDropDownList(blogpostToUpdate.TagId);
return(View("~/Views/Blogpost/Edit.cshtml", blogpostToUpdate));
}
