Clean schema implementation for field schema

1. +++ b/src/Plugin/Field/FieldType/JsonItem.php
   @@ -33,6 +33,8 @@ class JsonItem extends FieldItemBase {
              'type' => 'json',
   +          'pgsql_type' => 'json',
   +          'mysql_type' => 'json',
   

   json isn't a valid generic type according to the schema API, nor a valid MySQL type. However I don't see a reason why this module can't store the serialised string as text on non PostgreSQL databases.

2. +++ b/src/Plugin/Field/FieldType/JsonbItem.php
   @@ -32,7 +31,9 @@ class JsonbItem extends FieldItemBase {
   +          'type' => 'text',
   +          'pgsql_type' => 'jsonb',
   +          'mysql_type' => 'json',
   

   As above, the MySQL type isn't valid here. We can probably remove the MySQL specific line and default to the generic text type.

MySQL JSON has implemented a JSON type as of MySQL JSON 5.7.7. It reads like their implementation is the combination of both JSON/JSONB from Postgres.

It is only a labs release right now. When will it be merged into the main MySQL branch, I am not sure.

Will do.

I suspect we will need a way to implement JSON specific query altering as well? Or should we leave that to developers just wanting to store the data? Might be quite useful to work in Views support at the least.

I haven't forgotten about this. I am trying to get MySQL version selection into my VM build so I am not limited to just Postgres.

Rerolled #1, because FormatterBase::viewElements function has changed.

Patch has been applied and pushed to dev for review

andypost & erik, are we good here in 8.1.x?