Let mobile form declare if/how to auto-focus a field

and for mobile ordering, auto-focus the "units" field when editing a row

tailbone/static/js/tailbone.mobile.js

@@ -50,7 +50,8 @@ $(document).on('autocompleteitemselected', function(event, uuid) {
 
 /**
  * Automatically set focus to certain fields, on various pages
- * TODO: this should accept selector params instead of hard-coding..?
+ * TODO: should be letting the form declare a "focus spec" instead, to avoid
+ * hard-coding these field names below!
  */
 function setfocus() {
     var el = null;
@@ -73,6 +74,21 @@ $(document).on('pageshow', function() {
 
     setfocus();
 
+    // if current page has form, which has declared a "focus spec", then try to
+    // set focus accordingly
+    var form = $('.ui-page-active form');
+    if (form) {
+        var spec = form.data('focus');
+        if (spec) {
+            var input = $(spec);
+            if (input) {
+                if (input.is(':visible')) {
+                    input.focus();
+                }
+            }
+        }
+    }
+
 });