Changes between Version 1 and Version 2 of BossaExampleFour


Ignore:
Timestamp:
07/31/08 14:19:00 (9 years ago)
Author:
davea
Comment:

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  • BossaExampleFour

    v1 v2  
    2323Using the administrative interface, create an application named "bossa_example4".
    2424Create a directory '''~/projects/test/html/user/example4_images'''.
    25 Put some images (.png or .jpg) there; a good source is
     25Put some images (.png or .jpg) there; some sample images are in
    2626http://isaac.ssl.berkeley.edu/test/example4_images/
    2727
     
    3232}}}
    3333
    34 ==
     34== Opaque data ==
     35
     36The application uses the following opaque data:
     37
     38 * Jobs
     39{{{
     40path: the name of image file
     41}}}
     42 * Instances
     43{{{
     44features: an array of structures, each containing:
     45
     46x: the X coordinate of the center
     47y: the Y coordinate of the center
     48type: the feature type (Tooth, Skull, Other)
     49comment: the user-supplied comment
     50}}}
     51
     52== Callback functions ==
     53
     54The '''job_show()''' function displays the image and overlays
     55existing annotations.
     56Each one is shown as a box with an "info" button
     57(which pops up the type and comment)
     58and a "delete" button linked to the edit page.
     59
     60The image is an input item in a form linked to the edit page,
     61so that clicks on the image produce a new annotation.
     62Javascript is used to require that a feature type be selected
     63in order for the annotation to be accepted.
     64
     65The "Done" button is linked to '''bossa_job_finished.php'''.
     66
     67== The edit handler ==
     68
     69The edit handler is invoked with the following GET arguments:
     70
     71 * '''bji''': the ID of the instance
     72 * '''action''': "add", "delete", or "" (to display the image)
     73 * '''pic_x''' and '''pic_y''' (if action is "add")
     74
     75The code is as follows.
     76The first two functions add and delete annotations;
     77each one ends by redirecting to the same page with no "action" argument;
     78this will redisplay the image with the new set of annotations.
     79{{{
     80     7  function handle_add($job, $inst) {
     81     8      $f = null;
     82     9      $f->x = get_int('pic_x');
     83    10      $f->y = get_int('pic_y');
     84    11      $f->type = get_str('type');
     85    12      $c = get_str('comment', true);
     86    13      if (strstr($c, "(optional)")) $c = "";
     87    14      $f->comment = $c;
     88    15      $output = $inst->get_opaque_data();
     89    16      $output->features[] = $f;
     90    17      $inst->set_opaque_data($output);
     91    18      header("location: bossa_example4.php?bji=$inst->id");
     92    19  }
     93    20
     94    21  function handle_delete($job, $inst, $index) {
     95    22      $output = $inst->get_opaque_data();
     96    23      $features = $output->features;
     97    24      array_splice($features, $index, 1);
     98    25      $output->features = $features;
     99    26      $inst->set_opaque_data($output);
     100    27      header("location: bossa_example4.php?bji=$inst->id");
     101    28  }
     102}}}
     103
     104The main part of the script is as follows.
     105First, we get the instance ID and call a Bossa API function
     106to get the job, instance, and user:
     107{{{
     108    30  $bji = get_int("bji");
     109    31  if (!bossa_lookup_job($bji, $job, $inst, $u)) {
     110    32      error_page("No such instance");
     111    33  }
     112}}}
     113Then we verify that this instance belongs to the logged-in user:
     114{{{
     115    34  $user = get_logged_in_user();
     116    35  if ($u->id != $user->id) {
     117    36      error_page("Not your job");
     118    37  }
     119}}}
     120Then we perform the operation (or show the image with existing annotations):
     121{{{
     122    39  $action = get_str("action", true);
     123    40  switch ($action) {
     124    41  case "add":
     125    42      handle_add($job, $inst);
     126    43      break;
     127    44  case "delete":
     128    45      $index = get_int("index");
     129    46      handle_delete($job, $inst, $index);
     130    47      break;
     131    48  default:
     132    49      job_show($job, $inst, $user);
     133    50      break;
     134    51  }
     135    52
     136    53  ?>
     137}}}