Changes between Version 5 and Version 6 of BossaExampleOne

Timestamp:

Feb 11, 2008, 12:58:30 PM (16 years ago)

Author:

davea

Comment:

--

BossaExampleOne

@@ -30 +30 @@
 
 Visit http://a.b.c/test_ops/bossa_ops.php,
-and create an application named "test",
-with application file "test.php" (we'll create this later).
+and create an application named "example",
+with display file "bossa_example.php"
+and backend file "bossa_example_backend.inc".
 
 == A script to generate jobs ==
@@ -119 +120 @@
 '''http://a.b.c/test_ops/bossa_test.php?make_jobs'''.
 
-
-
-== Create jobs ==
+== Displaying jobs ==
+
+Next we'll need a script that displays a job and handles user input.
+{{{
+function show_job($bj, $bji) {
+    $info = json_decode($bj->info);
+    $img_url = $info.url;
+    echo "
+        <form method=get action=bossa_example.php>
+        Click on the center of the ellipse.
+        If you don't see one, click here:
+        <br><br><input type=submit name=submit value=None>
+        <input type=hidden name=bji value=$bji->id>
+        <input type=hidden name=completion value=1>
+        <input type=image name=pic src=$img_url>
+        </form>
+    ";
+}
+
+function handle_job_completion($bj, $bji) {
+    $response = null;
+    if (get_str('submit', true)) {
+        $response->have_ellipse = 0;
+    } else {
+        $response->have_ellipse = 1;
+        $response->cx = get_int('pic.x');
+        $response->cy = get_int('pic.y');
+    }
+    $bji->info = json_encode($response);
+    $bji->completed($bj);
+    Bossa::show_next_job($bj);    // show another job immediately
+}
+
+Bossa::script_init($user, $bj, $bji);
+
+if (isset($_GET['completion'])) {
+    handle_job_completion($bj, $bji);
+} else {
+    show_job($bj, $bji);
+}
+}}}
 
 == What volunteers see ==
 
-== View results ==
+== Handling completed results ==
+
+Finally, we need to specify how results are handled.
+This is specified in "html/inc/bossa_example.inc".
+
+This defines two functions.
+The first defines a comparison of two results:
+{{{
+function compare($r1, $r2) {
+    if ($r1->have_ellipse) {
+        if ($r2->have_ellipse) {
+            $dx = ($r1->cx - $r2->cx);
+            $dy = ($r1->cy - $r2->cy);
+            $dsq = $dx*$dx + $dy*$dy;
+            return ($dsq < 400);
+        } else return false;
+    } else {
+        return !$r2->have_ellipse;
+    }
+}
+}}}
+
+The second function specifies what happens when a
+job has been completed, i.e. a consensus set has been found:
+{{{
+function handle_consensus($bj, $c) {
+    $res = $c[0];
+    if ($res->have_ellipse) {
+        $res->cx = 0;
+        $res->cy = 0;
+        foreach ($c as $r) {
+            $res->cx += $r->cx;
+            $res->cy += $r->cy;
+        }
+        $res->cx /= count($c);
+        $res->cy /= count($c);
+    }
+
+    $info = json_decode[$bj->info);
+    $info->result = $res;
+    $i = json_encode($info);
+    $bj->update("info='$i'");
+}
+}}}
+