feature: for_attribute option for fields (#180)

* feature: association option for association fields

* refactor

docs/3.0/associations/has_and_belongs_to_many.md

@@ -37,3 +37,4 @@ Similar to [`belongs_to`](./belongs_to#searchable-belongs-to), the `has_many` as
 <!-- @include: ./../common/scopes_common.md-->
 <!-- @include: ./../common/show_hide_buttons_common.md-->
 <!-- @include: ./../common/reloadable.md-->
+<!-- @include: ./../common/association.md-->

docs/3.0/associations/has_many.md

@@ -39,3 +39,4 @@ field :members,
 <!-- @include: ./../common/scopes_common.md-->
 <!-- @include: ./../common/show_hide_buttons_common.md-->
 <!-- @include: ./../common/reloadable.md-->
+<!-- @include: ./../common/association.md-->

docs/3.0/common/association.md

@@ -0,0 +1,16 @@
+:::option `association`
+
+<VersionReq version="3.6.2" />
+
+The `for_attribute` option allows to specify the association used for a certain field. This option make possible to define same association with different scopes and different name several times on the same resource.
+
+#### Usage
+```ruby-vue
+field :reviews,
+  as: :{{ $frontmatter.field_type }}
+
+field :special_reviews,
+  as: :{{ $frontmatter.field_type }},
+  for_attribute: :reviews,
+  scope: -> { query.special_reviews }
+```

docs/3.0/field-options.md

@@ -643,6 +643,25 @@ field :name, as: :text, html: {
 field :status, as: :select, summarizable: true
 # or
 field :status, as: :badge, summarizable: true
+```
+This section is WIP.
 :::
 
-This section is WIP.
+:::option `for_attribute`
+<VersionReq version="3.6.2" />
+
+Allows to specify the target attribute on the model for each field. By default the target attribute is the field's id.
+
+Usage example:
+
+```ruby{6}
+    field :name,
+      as: :text
+
+    field :secondary_field_for_name,
+      as: :text,
+      for_attribute: :name,
+      only_on: :edit,
+      help: "Secondary field for name using for_attribute option"
+```
+:::