在选项php中设置选择：未定义的属性

Question

Can someone explain me why I can't list items in select control? If I disable public $team_id in my Team class, and make new object $selectedHome_id , and after that correct this line of code to $selectedHome_id == $team->team_id I can list data, but I can't select the item.

image

matches.php

<?php include("config.php"); 
  $selectedTeam = new Team();

  if (isset($_GET['htid'])) {
  $selectedHome_id = Team::getById($_GET['htid']);
  } 
  ?>

<select class="custom-select-sm" id="inputGroupSelect01" aria-label="Small" aria-describedby="inputGroup-sizing-sm" onchange="window.location='?htid='+this.value" name="selHomeTeam">
                    <option value="-1">Choose...</option>
                    <?php 
                    $selectedHome_id = new Team();
                    $teams = Team::getAll();
                    foreach ($teams as $team) {
                      echo "<option " .($selectedHome_id->team_id== $team->team_id?"selected":""). " value='{$team->team_id}'>{$team->name}</option>";
                    }
                    ?>
                    <option value="1">One</option>
                    <option value="2">Two</option>
                    <option value="3">Three</option>
                  </select>

Team.php

class Team extends ActiveRecord {
public $team_id; 
public $name;
public static $table = "teams";
public static $key = "team_id";
}

Answer 1

So you check to see if you have been passed a $_GET['htid'] and, if you have, then you get that Team . Then, within your options, you promptly replace this with a new Team -- what do you think the team_id would be set to, with this new Team ?

Perhaps, rather than

if (isset($_GET['htid'])) {
  $selectedHome_id = Team::getById($_GET['htid']);
} 

you may want to

if (isset($_GET['htid'])) {
  $selectedHome_id = Team::getById($_GET['htid']);
} else {
  $selectedHome_id = new Team(); 
}

By doing this, when you get to the ternary comparison in your option, $selectedHome_id is set to something.

Without seeing the full code, though, we lack both intent and context.