Add control code preview generation

Signed-off-by: Roberto Rosario <roberto.rosario@mayan-edms.com>

mayan/apps/control_codes/forms.py

@@ -0,0 +1,65 @@
+from __future__ import unicode_literals
+
+import yaml
+
+from django import forms
+from django.core.exceptions import ValidationError
+from django.utils.translation import ugettext_lazy as _
+
+from mayan.apps.common.serialization import yaml_load
+
+from .classes import ControlCode
+from .models import ControlSheetCode
+
+
+class ControlCodeClassSelectionForm(forms.Form):
+    control_code = forms.ChoiceField(
+        choices=(), help_text=_('Available control codes.'),
+        label=_('Control code'),
+    )
+
+    def __init__(self, *args, **kwargs):
+        super(ControlCodeClassSelectionForm, self).__init__(*args, **kwargs)
+
+        self.fields[
+            'control_code'
+        ].choices = ControlCode.get_choices()
+
+
+"""
+class ControlSheetCodeForm(forms.ModelForm):
+    class Meta:
+        fields = ('arguments', 'order')
+        model = LayerTransformation
+
+    def __init__(self, *args, **kwargs):
+        transformation_name = kwargs.pop('transformation_name', None)
+        super(LayerTransformationForm, self).__init__(*args, **kwargs)
+
+        if not transformation_name:
+            # Get the template name when the transformation is being edited.
+            template_name = getattr(
+                self.instance.get_transformation_class(), 'template_name',
+                None
+            )
+        else:
+            # Get the template name when the transformation is being created
+            template_name = getattr(
+                BaseTransformation.get(name=transformation_name),
+                'template_name', None
+            )
+
+        if template_name:
+            self.fields['arguments'].widget.attrs['class'] = 'hidden'
+            self.fields['order'].widget.attrs['class'] = 'hidden'
+
+    def clean(self):
+        try:
+            yaml_load(stream=self.cleaned_data['arguments'])
+        except yaml.YAMLError:
+            raise ValidationError(
+                _(
+                    '"%s" not a valid entry.'
+                ) % self.cleaned_data['arguments']
+            )
+"""