[filtering] define combo of slice/fields unafected by filtering

caravel/assets/javascripts/dashboard/Dashboard.jsx

@@ -82,6 +82,32 @@ function dashboardContainer(dashboardData) {
     setFilter(sliceId, col, vals, refresh) {
       this.addFilter(sliceId, col, vals, false, refresh);
     },
+    effectiveExtraFilters(sliceId) {
+      // Summarized filter, not defined by sliceId
+      // returns k=field, v=array of values
+      const f = {};
+      if (sliceId && this.metadata.filter_immune_slices.includes(sliceId)) {
+        // The slice is immune to dashboard fiterls
+        return f;
+      }
+
+      // Building a list of fields the slice is immune to filters on
+      let immuneToFields = [];
+      if (
+            sliceId &&
+            this.metadata.filter_immune_slice_fields &&
+            this.metadata.filter_immune_slice_fields[sliceId]) {
+        immuneToFields = this.metadata.filter_immune_slice_fields[sliceId];
+      }
+      for (const filteringSliceId in this.filters) {
+        for (const field in this.filters[filteringSliceId]) {
+          if (!immuneToFields.includes(field)) {
+            f[field] = this.filters[filteringSliceId][field];
+          }
+        }
+      }
+      return f;
+    },
     addFilter(sliceId, col, vals, merge = true, refresh = true) {
       if (!(sliceId in this.filters)) {
         this.filters[sliceId] = {};

caravel/assets/javascripts/modules/caravel.js

@@ -81,9 +81,13 @@ const px = function () {
         const parser = document.createElement('a');
         parser.href = data.json_endpoint;
         if (dashboard !== undefined) {
-          const flts =
-            newParams.extraFilters === false ? '' :
-              encodeURIComponent(JSON.stringify(dashboard.filters));
+          let flts;
+          if (newParams.extraFilters === false) {
+            flts = '';
+          } else {
+            flts = dashboard.effectiveExtraFilters(sliceId);
+            flts = encodeURIComponent(JSON.stringify(flts));
+          }
           qrystr = parser.search + '&extra_filters=' + flts;
         } else if ($('#query').length === 0) {
           qrystr = parser.search;

caravel/assets/visualizations/filter_box.jsx

@@ -25,6 +25,29 @@ const defaultProps = {
   showDateFilter: false,
 };
 
+const TIME_CHOICES = [
+  '1 hour ago',
+  '12 hours ago',
+  '1 day ago',
+  '7 days ago',
+  '28 days ago',
+  '90 days ago',
+  '1 year ago',
+];
+
+const propTypes = {
+  origSelectedValues: React.PropTypes.object,
+  filtersChoices: React.PropTypes.object,
+  onChange: React.PropTypes.func,
+  showDateFilter: React.PropTypes.bool,
+};
+
+const defaultProps = {
+  origSelectedValues: {},
+  onChange: () => {},
+  showDateFilter: false,
+};
+
 class FilterBox extends React.Component {
   constructor(props) {
     super(props);

caravel/utils.py

@@ -445,6 +445,14 @@ def generic_find_constraint_name(table, columns, referenced, db):
             return fk.name
 
 
+def validate_json(obj):
+    if obj:
+        try:
+            json.loads(obj)
+        except Exception:
+            raise CaravelException("JSON is not valid")
+
+
 class timeout(object):
     """
     To be used in a ``with`` block and timeout its content.

caravel/views.py

@@ -850,6 +850,8 @@ def pre_add(self, obj):
             obj.slug = re.sub(r'\W+', '', obj.slug)
         if g.user not in obj.owners:
             obj.owners.append(g.user)
+        utils.validate_json(obj.json_metadata)
+        utils.validate_json(obj.position_json)
 
     def pre_update(self, obj):
         check_ownership(obj)
@@ -1369,6 +1371,8 @@ def save_dash(self, dashboard_id):
         md = dash.metadata_dejson
         if 'filter_immune_slices' not in md:
             md['filter_immune_slices'] = []
+        if 'filter_immune_slice_fields' not in md:
+            md['filter_immune_slice_fields'] = {}
         md['expanded_slices'] = data['expanded_slices']
         dash.json_metadata = json.dumps(md, indent=4)
         dash.css = data['css']

caravel/viz.py

@@ -196,12 +196,7 @@ def get_extra_filters(self):
         extra_filters = self.form_data.get('extra_filters')
         if not extra_filters:
             return {}
-        extra_filters = json.loads(extra_filters)
-        # removing per-slice details
-        summary = {}
-        for flt in extra_filters.values():
-            summary.update(flt)
-        return summary
+        return json.loads(extra_filters)
 
     def query_filters(self, is_having_filter=False):
         """Processes the filters for the query"""

docs/faq.rst

@@ -61,3 +61,51 @@ Why is the map not visible in the mapbox visualization?
 
 You need to register to mapbox.com, get an API key and configure it as
 ``MAPBOX_API_KEY`` in ``caravel_config.py``.
+
+
+How to add dynamic filters to a dashboard?
+------------------------------------------
+
+It's easy: use the ``Filter Box`` widget, build a slice, and add it to your
+dashboard.
+
+The ``Filter Box`` widget allows you to define a query to populate dropdowns
+that can be use for filtering. To build the list of distinct values, we
+run a query, and sort the result by the metric you provide, sorting
+descending.
+
+The widget also has a checkbox ``Date Filter``, which enables time filtering
+capabilities to your dashboard. After checking the box and refreshing, you'll
+see a ``from`` and a ``to`` dropdown show up.
+
+But what about if you don't want certain widgets to get filtered on your
+dashboard? You can do that by editing your dashboard, and in the form,
+edit the ``JSON Metadata`` field, more specifically the
+``filter_immune_slices`` key, that receives an array of sliceIds that should
+never be affected by any dashboard level filtering.
+
+
+..code::
+
+    {
+        "filter_immune_slices": [324, 65, 92],
+        "expanded_slices": {},
+        "filter_immune_slice_fields": {
+            "177": ["country_name", "__from", "__to"],
+            "32": ["__from", "__to"]
+        }
+    }
+
+In the json blob above, slices 324, 65 and 92 won't be affected by any
+dashboard level filtering.
+
+Now note the ``filter_immune_slice_fields`` key. This one allows you to
+be more specific and define for a specific slice_id, which filter fields
+should be disregarded.
+
+Note the use of the ``__from`` and ``__to`` keywords, those are reserved
+for dealing with the time boundary filtering mentioned above.
+
+But what happens with filtering when dealing with slices coming from
+different tables or databases? If the column name is shared, the filter will
+be applied, it's as simple as that.