/// <summary>Shows material by specified Id.</summary>
/// <param name="id">Material identifier.</param>
/// <returns>Material page.</returns>
public async Task <ActionResult> Material(int id)
{
var material = _materialService.GetMaterialWithWords(id);
if (material == null)
{
return(RedirectToAction("DisplayAll")); // TODO: change to main page redirect.
}
var vocabWords = await FillVocabWordsByMaterial(material); //TODO: do not take words to material.
var imgSrc = GetMaterialImageUrl(material.Id);
return(View(new MaterialViewModel(material, vocabWords, ImageMaxWidth, ImageMaxHeight, imgSrc)));
}