Adding child entity works locally but not on live Azure site - asp.net-mvc

Question

I have a web app controller action that is creating a child entity. I have a Location model with a LocationPic collection. I'm trying to add a new LocationPic to an existing Location. Locally this works fine, but when I run it on Azure the LocationPic gets created but doesn't reference the Location. So I end up with an orphaned LocationPic that doesn't know what Location it belongs to.
Also, it works fine locally and on Azure for Locations that ALREADY have pics (I have a separate API controller that seems to work fine). So I can add new pics to Locations that already have some. But I can't add new pics to a new Location that doesn't have any pics.
Here's my controller action:
// POST: Pictures/Create
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("LocationID,Name,Description")] LocationPic locationPic, IFormFile image)
{
var location = await _context.Locations.FindAsync(locationPic.LocationID);
if (location == null)
{
return NotFound();
}
Trace.TraceInformation($"Create Pic for location[{location.LocationID}:{location.LocationName}]");
_userService = new UserService((ClaimsIdentity)User.Identity, _context);
if (!_userService.IsAdmin)
{
return Unauthorized();
}
if (image == null)
{
return BadRequest();
}
if (String.IsNullOrEmpty(locationPic.Name))
{
locationPic.Name = image.FileName;
}
var helper = new AzureTools();
var filename = await helper.GetFileName(image);
locationPic.FileName = filename;
//Added this to try to force LocationPics to be initialized
if (location.LocationPics == null)
{
Trace.TraceInformation("location.LocationPics is null");
location.LocationPics = new List<LocationPic>();
}
else
{
Trace.TraceInformation($"location.LocationPics count == {location.LocationPics.Count}");
}
if (ModelState.IsValid)
{
Trace.TraceInformation($"Location pic valid: [{locationPic.LocationID}] {locationPic.Name}");
//Overly-explicit attempts to get entities linked
locationPic.Location = location;
location.LocationPics.Add(locationPic);
//I've tried _context.LocationPics.Add as well and seemingly no difference
_context.Add(locationPic);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(Edit), new { locationID = location.LocationID });
} else
{
Trace.TraceInformation("Invalid model state");
return BadRequest();
}
}
All the right information seems to be coming into my parameters from my form properly, and the LocationPic gets created fine. It just isn't linked to the Location, despite the "LocationID" showing properly before being saved. Plus, I get the proper redirect back to the Edit action, not a BadRequest or anything.
Locally, the only difference I've noticed is that a Location with no pics has a LocationPics that is an empty collection with Count==0. On Azure, a Location with no pics seems to have a LocationPics that is null. So that's why I tried to add the bit that initializes it if it's null, though my API controller that works didn't need to do anything of the sort.
Here's my (working) API Controller action, for reference:
[HttpPost("{id}", Name = "PostPicture")]
public async Task<IActionResult> PostPicture([FromRoute] int id, IFormFile image, string Name, string Description)
{
var location = _context.Locations.Find(id);
if (location == null)
{
return NotFound();
}
_userService = new UserService((ClaimsIdentity)User.Identity, _context);
if (!_userService.IsCustomer(location.CustomerID))
{
return Unauthorized();
}
if (image == null)
{
return BadRequest();
}
if (String.IsNullOrEmpty(Name))
{
Name = image.FileName;
}
var helper = new AzureTools();
var filename = await helper.GetFileName(image);
var locationPic = new LocationPic
{
Name = Name,
FileName = filename,
Description = Description,
Location = location
};
_context.LocationPics.Add(locationPic);
_context.SaveChanges();
return Ok(filename);
}

Answer 1

Turns out the location pics were going in fine, but in my controller actions that I was displaying them I wasn't using .Include() to include the LocationPics collection? Except that it worked for Locations that previously had location pics? And it worked locally totally fine for everything. So I'm not entirely sure.
As soon as I put .Include() to include the LocationPics collection in my "EditByLocation" controller action that grabs a location by ID and sends that to the view that displays the location and pics for that location, all the previous pics I'd added popped into view on the locations that I thought weren't getting them. So for some reason, Location A (with pics) was displaying its pics fine, but Location B (apparently with pics but I couldn't see them until now) wasn't displaying them. I had no reason to believe that the locations weren't displaying correctly because some were displaying fine, and others came over with a null LocationPics collection. So that makes no sense to me. But it seems to be working now.
For completeness, here is my final controller action code, which you may notice looks very similar to the API controller action, which is what it looked like to start with:
// POST: Pictures/Create
[HttpPost]
[ValidateAntiForgeryToken]
public async Task<IActionResult> Create([Bind("LocationID,Name,Description")] LocationPic locationPic, IFormFile image)
{
var location = await _context.Locations.FindAsync(locationPic.LocationID);
if (location == null)
{
return NotFound();
}
_userService = new UserService((ClaimsIdentity)User.Identity, _context);
if (!_userService.IsAdmin)
{
return Unauthorized();
}
if (image == null)
{
return BadRequest();
}
if (String.IsNullOrEmpty(locationPic.Name))
{
locationPic.Name = image.FileName;
}
var helper = new AzureTools();
var filename = await helper.GetFileName(image);
locationPic.FileName = filename;
if (ModelState.IsValid)
{
locationPic.Location = location;
_context.LocationPics.Add(locationPic);
await _context.SaveChangesAsync();
return RedirectToAction(nameof(EditByLocation), new { locationID = location.LocationID });
}
return View("EditByLocation", location);
}
And here's my new EditByLocation controller action:
// GET: Pictures/EditByLocation?locationID=5
public async Task<IActionResult> EditByLocation(int locationID)
{
_userService = new UserService((ClaimsIdentity)User.Identity, _context);
if (!_userService.IsAdmin)
{
return Unauthorized();
}
ViewData["ImageBaseUrl"] = _config["AzureStorage:Url"] + "/" + _config["AzureStorage:Folder"];
var location = await _context.Locations.Include(l => l.LocationPics).FirstOrDefaultAsync(l => l.LocationID == locationID);
if (location == null)
{
return NotFound();
}
if (location.LocationPics == null)
{
location.LocationPics = new List<LocationPic>();
}
return View("EditByLocation", location);
}
The only real change above was adding the .Include(l => l.LocationPics). So again, no idea why it worked locally without it, and why SOME locations worked on Azure without it but not others.