From ad430a31735e42684fbce79c52959e1398389b98 Mon Sep 17 00:00:00 2001
From: jos <wjosdejong@gmail.com>
Date: Sat, 4 Jan 2020 12:21:01 +0100
Subject: [PATCH] Improve example with a `projection` which flattens the
 selected fields

---
 examples/23_custom_query_language.html | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/examples/23_custom_query_language.html b/examples/23_custom_query_language.html
index 9cbe2fd..c6e8d43 100644
--- a/examples/23_custom_query_language.html
+++ b/examples/23_custom_query_language.html
@@ -72,7 +72,14 @@
       }
 
       if (projection) {
-        query = `_.map(${query}, item => _.pick(item, ${JSON.stringify(projection.fields)}))`
+        // It is possible to make a util function "pickFlat"
+        // and use that when building the query to make it more readable.
+        const fields = projection.fields.map(field => {
+          const name = _.last(field.split('.'))
+          return `  '${name}': _.get(item, '${field}')`
+        })
+
+        query = `_.map(${query}, item => ({\n${fields.join(',\n')}})\n)`
       }
 
       return query