TASK: Allow fields and sorting to contain a condition

This way integrators can configure when the sorting and fields should be
added.

Classes/Domain/Search/QueryFactory.php

@@ -165,7 +165,10 @@ class QueryFactory
         try {
             $scriptFields = $this->configuration->get('searching.fields.script_fields');
             $scriptFields = $this->replaceArrayValuesWithRequestContent($searchRequest, $scriptFields);
+            $scriptFields = $this->filterByCondition($scriptFields);
+            if ($scriptFields !== []) {
                 $query = ArrayUtility::arrayMergeRecursiveOverrule($query, ['script_fields' => $scriptFields]);
+            }
         } catch (InvalidArgumentException $e) {
             // Nothing configured
         }
@@ -175,8 +178,11 @@ class QueryFactory
     {
         $sorting = $this->configuration->getIfExists('searching.sort') ?: [];
         $sorting = $this->replaceArrayValuesWithRequestContent($searchRequest, $sorting);
+        $sorting = $this->filterByCondition($sorting);
+        if ($sorting !== []) {
             $query = ArrayUtility::arrayMergeRecursiveOverrule($query, ['sort' => $sorting]);
         }
+    }
 
     protected function addFilter(SearchRequestInterface $searchRequest, array &$query)
     {
@@ -254,4 +260,19 @@ class QueryFactory
 
         return $array;
     }
+
+    protected function filterByCondition(array $entries) : array
+    {
+        $entries = array_filter($entries, function ($entry) {
+            return !array_key_exists('condition', $entry) || (bool) $entry['condition'] === true;
+        });
+
+        foreach ($entries as $key => $entry) {
+            if (array_key_exists('condition', $entry)) {
+                unset($entries[$key]['condition']);
+            }
+        }
+
+        return $entries;
+    }
 }

Documentation/source/configuration/searching.rst

@@ -41,8 +41,8 @@ facets
 
 .. _filter:
 
-``filter``
-"""""""""""
+filter
+------
 
 Used by: While building search request.
 
@@ -107,10 +107,92 @@ fieldValueFactor
         missing = 1
     }
 
+.. _mapping.filter:
+
+mapping.filter
+--------------
+
+Allows to configure filter more in depth. If a filter with the given key exists, the TypoScript will
+be added.
+
+E.g. you submit a filter in form of:
+
+.. code-block:: html
+
+    <f:form.textfield property="filter.distance.location.lat" value="51.168098" />
+    <f:form.textfield property="filter.distance.location.lon" value="6.381384" />
+    <f:form.textfield property="filter.distance.distance" value="100km" />
+
+This will create a ``distance`` filter with subproperties. To make this filter actually work, you
+can add the following TypoScript, which will be added to the filter::
+
+    mapping {
+        filter {
+            distance {
+                field = geo_distance
+                fields {
+                    distance = distance
+                    location = location
+                }
+            }
+        }
+    }
+
+``fields`` has a special meaning here. This will actually map the properties of the filter to fields
+in elasticsearch. In above example they do match, but you can also use different names in your form.
+On the left hand side is the elasticsearch field name, on the right side the one submitted as a
+filter.
+
+The ``field``, in above example ``geo_distance``, will be used as the elasticsearch field for
+filtering. This way you can use arbitrary filter names and map them to existing elasticsearch fields.
+
+.. _fields:
+
+fields
+------
+
+Defines the fields to fetch from elasticsearch. Two sub entries exist:
+
+First ``stored_fields`` which is a list of comma separated fields which actually exist and will be
+added. Typically you will use ``_source`` to fetch the whole indexed fields.
+
+Second is ``script_fields``, which allow you to configure scripted fields for elasticsearch.
+An example might look like the following::
+
+    fields {
+        script_fields {
+            distance {
+                condition = {request.filter.distance.location}
+                script {
+                    params {
+                        lat = {request.filter.distance.location.lat -> f:format.number()}
+                        lon = {request.filter.distance.location.lon -> f:format.number()}
+                    }
+                    lang = painless
+                    inline = doc["location"].arcDistance(params.lat,params.lon) * 0.001
+                }
+            }
+        }
+    }
+
+In above example we add a single ``script_field`` called ``distance``. We add a condition when this
+field should be added. The condition will be parsed as Fluidtemplate and is casted to bool via PHP.
+If the condition is true, or no ``condition`` exists, the ``script_field`` will be added to the
+query. The ``condition`` will be removed and everything else is submitted one to one to
+elasticsearch, except each property is run through Fluidtemplate, to allow you to use information
+from search request, e.g. to insert latitude and longitude from a filter, like in the above example.
+
+.. _sort:
+
+sort
+----
+
+Sort is handled like :ref:`fields`.
+
 .. _mode:
 
-``mode``
-""""""""
+mode
+----
 
 Used by: Controller while preparing action.