path resource_id to each chart field form snippet

ckanext/charts/templates/charts/snippets/charts_form_field.html

@@ -0,0 +1,14 @@
+{#- master snippet for all charts form fields -#}
+
+{%- set form_snippet = field.form_snippet|default('repeating_subfields.html' if field.repeating_subfields else 'text.html') -%}
+
+{%- if '/' not in form_snippet -%}
+    {%- set form_snippet = 'scheming/form_snippets/' + form_snippet -%}
+{%- endif -%}
+
+{%- snippet form_snippet,
+    field=field,
+    data=data,
+    errors=errors,
+    resource_id=resource_id
+-%}

ckanext/charts/templates/charts/snippets/charts_form_fields.html

@@ -40,8 +40,12 @@
             {% if tab_fields %}
                 <div class="tab-pane fade {{ 'show active' if tab == active_tab }}" id="pills-{{ tab }}" role="tabpanel"
                     aria-labelledby="pills-{{ tab }}-tab">
-                    {% snippet 'charts/snippets/render_fields.html', fields=builder.get_fields_by_tab(tab), data=data,
-                    errors=errors %}
+                    {% snippet 'charts/snippets/render_fields.html',
+                        fields=builder.get_fields_by_tab(tab),
+                        data=data,
+                        errors=errors,
+                        resource_id=resource_id
+                    %}
                 </div>
             {% endif %}
         {% endfor %}

ckanext/charts/templates/charts/snippets/render_fields.html

@@ -1,3 +1,3 @@
 {% for field in fields if field.form_snippet is not none %}
-    {% snippet 'scheming/snippets/form_field.html', field=field, data=data, errors=errors %}
+    {% snippet 'charts/snippets/charts_form_field.html', field=field, data=data, errors=errors, resource_id=resource_id %}
 {% endfor %}

ckanext/charts/templates/scheming/form_snippets/chart_filter.html

@@ -1,6 +1,3 @@
-{#} HACK, pass resource ID more explicitly #}
-{% set resource_id = data.__extras.resource_id %}
-
 <div
     class="form-group control-full control-large charts-filters"
     data-module="charts-filters"