LINQ Tutorials

@inherits Custom.Hybrid.Razor14
@using System.Linq;
@using Dynlist = System.Collections.Generic.IEnumerable<dynamic>;

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@{
  var persons = AsList(App.Data["Persons"]);
  var books = AsList(App.Data["Books"]);
}

@Html.Partial("_header.cshtml")

<div class="row">
  <div class="col-lg-7">
    <h3>Find Parents of Authors - Things that point to Authors</h3>
    <p>In this example, we'll start with the authors list. This is probably not ideal - as some people are not authors, but it's a good learning example. To find the books we have to navigate through <code>Parents(...)</code> because in our data-model, the books reference authors, not the authors to books.</p>
  </div>
  @Html.Partial("../shared/_DefaultInfoSection.cshtml")
</div>

<ol>
  @foreach(var author in persons) {
    // this line would work, if Books only had people in the Authors. 
    // but it doesn't, there are also illustrators, which is why we use the second example instead
    var peoplesBooks = author.Parents("Books");
    var authorsBooks = author.Parents("Books", "Authors");

    <li>
      @author.FirstName @author.LastName
      <ul>
        @foreach(var book in authorsBooks) {
          var coAuthors = (book.Authors as Dynlist).Where(a => a != author);
          <li>
            <strong>@book.Title</strong> 
            @if(coAuthors.Any()) {
              <span>co-authored by 
                @string.Join(",", coAuthors.Select(a => a.FirstName + " " + a.LastName))
              </span>
            }
          </li>
        }
      </ul>
    </li>
  }
</ol>


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