Implement server side query building for flowr

app/controllers/flowr_controller.rb

@@ -0,0 +1,42 @@
+class FlowrController < ApplicationController
+
+  def insights
+    unless current_user
+      skip_authorization
+      respond_to do |format|
+        format.html { render_not_authorized }
+        format.json { render json: {}, status: :unauthorized }
+      end
+    else
+      # get the latest submission for this user that also has a test run (i.e. structured_errors if applicable)
+      submission = Submission.joins(:testruns)
+                       .where(submissions: {user_id: current_user.id, user_type: current_user.class.name})
+                       .order('testruns.created_at DESC').first
+      # verify authorization for the submission, as all queried errors are generated by this submission anyway
+      # and structured_errors don't have a policy yet
+      authorize(submission)
+      errors = StructuredError.where(submission_id: submission.id)
+
+      # for each error get all attributes, filter out uninteresting ones, and build a query
+      insights = errors.map do |error|
+        attributes = error.structured_error_attributes.select do |attribute|
+          is_interesting(attribute) and attribute.match
+        end
+        # once the programming language model becomes available, the language name can be added to the query to
+        # produce more relevant results
+        query = attributes.map{|att| att.value}.join(' ')
+        { submission: submission, error: error, attributes: attributes, query: query }
+      end
+
+      respond_to do |format|
+        format.html { render json: insights, status: :ok }
+        format.json { render json: insights, status: :ok }
+      end
+    end
+  end
+
+  def is_interesting(attribute)
+    attribute.error_template_attribute.key.index(/error message|error type/i) != nil
+  end
+  private :is_interesting
+end