If you’ve got an admin part in your rails app and some settings to take care of, chances are that you have a lot of similar data. And what can be more wearying, than creating all those forms, index/edit/new views over and over again? Of course you could use the scaffold, but I personally strongly dislike it.
So I figured out I try to make my partials variable as possible. This post shows you how you can create highly reusable form partials.
My structure is as following:
There is an admin panel. Inside admin panel there are settings (which get repetitive) and inside settings you can manage models like „colors“, „patterns“, „fabric“ (you can guess it – it’s a clothing online shop). All of them contain identical data, but have some differences as well.
I’ve got only 3 views – index, edit and new, because there is no sense for having a show view, as it should be the edit view right from the get go. This said, we need only two partials – one, for listing items inside our index view and one for creating and editing existing data.
Let’s start with routes.rb:
namespace :admin do
get '', to: 'dashboard#index', as: "/"
namespace :settings do
resources :borders
resources :colors
resources :patterns
resources :categories
resources :fabrics
end
end
Simple dashboard when you visit plain old „/admin“ and then resources inside another namespace „settings“.
My index view – index.html.haml:
=render partial: 'admin/shared/list_items', locals: {name_ru: 'ткань', current_objects: @fabrics, name_en: "fabric"}
As you can see, I pass 3 local variable to my partial (this is the only thing you need to edit for each model. But hey, it’s only 3 words!) – the russian name, so I can have some customized buttons and links. The current collection and the name in english.
Listing items partial (a.k.a. index)
.panel-body.pn
.table-responsive
%table.table.admin-form.theme-warning.tc-checkbox-1.fs13
%thead
%tr.bg-light
%th.text-center Select
%th Наименование
%th.text-right Статус
%tbody
-unless current_objects.nil?
-current_objects.each do |object|
%tr
%td.text-center
%label.option.block.mn
%input{:name => "mobileos", :type => "checkbox", :value => "FR"}
%span.checkbox.mn
%td
=link_to object.name, send("edit_admin_settings_#{single}_path", object)
%td.text-right
.btn-group.text-right
%button.btn.btn-success.br2.btn-xs.fs12.dropdown-toggle{"aria-expanded" => "false", "data-toggle" => "dropdown", :type => "button"}
Действия
%span.caret.ml5
%ul.dropdown-menu{:role => "menu"}
%li
=link_to 'Редактировать', send("edit_admin_settings_#{single}_path", object)
%li.divider
%li
=link_to 'Удалить', send("admin_settings_#{single}_path", object.id), method: :delete, data: {confirm: 'Действительно удалить?'}
%tr
%td
%td
%td.text-right
.btn-group.text-right
=link_to "Новая/ый #{name}", send("new_admin_settings_#{single}_path"), class: 'btn btn-primary'
Well, apart from some html, the important things are:
- to check if there is at least one item in the collection (remember, we pass the collection under the name „current_objects“)
- for each object in current_objects we access it using the variable „object“
- since our partial is variable we can’t use hardcoded paths, like „admin_settings_colors_path“. Meaning we must make use of the „send“ method, which basically makes a method from a string. To pass parameters to a method created by „send“ you simply put this parameter as a parameter to the send-method. send(„hello_there“, caramba) is equivalent to calling method hello_there(caramba)
- Because „object“ is actually an object (wow!) we can’t use it in the path generation. This is why I pass „single“ as a local variable. „Single“ is simply the singular form of the model (category, color, pattern etc.)
My edit/new view:
They are absolutely identical.
.tray.tray-center
=render 'admin/navigation/flash'
=render partial: 'admin/shared/form', locals: {current_object: @pattern}
I render some flash messages to tell users about successful or failed actions. Then I render my second partial using again a local variable to transmit the collection.
Form partial
The core 🙂
=form_for [:admin, :settings, current_objects] do |f|
.panel.mb25.mt5
.panel-heading
%span.panel-title.hidden-xs Добавить новую сущность
%ul.nav.panel-tabs-border.panel-tabs
%li.active
%a{"data-toggle" => "tab", :href => "#tab1_1"} Описание сущности
.panel-body.p20.pb10
.tab-content.pn.br-n.admin-form
.section.row.mbn
-if current_objects.respond_to?(:picture)
.col-md-4
.fileupload.fileupload-new.admin-form{"data-provides" => "fileupload"}
.fileupload-preview.thumbnail.mb20
-unless current_objects.picture.nil?
=image_tag current_objects.picture
-else
%img{:alt => "holder", "data-src" => "holder.js/100%x140"}
.row
.col-xs-7.pr5
%input#name2.text-center.event-name.gui-input.br-light.bg-light{:name => "name2", :placeholder => "Img Keywords", :type => "text"}
%label.field-icon{:for => "name2"}
.col-xs-5
%span.button.btn-system.btn-file.btn-block
%span.fileupload-new Select
%span.fileupload-exists Change
=f.file_field :picture, id: 'fileupload', type: :file
/ %input{:type => "file", name: 'picture'}
.col-md-8.pl15
.section.mb10
%label.field.prepend-icon{:for => "name2"}
=f.text_field :name, id: "price", class: "event-name gui-input br-light light", placeholder: 'Название сущности'
%label.field-icon{:for => "name2"}
%i.fa.fa-tag
-if current_objects.respond_to?(:price)
.section.mb10
%label.field.prepend-icon
=f.number_field :price, id: "price", class: "event-name gui-input br-light light", placeholder: 'Стоимость'
%label.field-icon{:for => "comment"}
%i.fa.fa-comments
%span.input-footer.hidden
%strong> Hint:
Don't be negative or off topic! just be awesome...
-if current_objects.respond_to?(:hex)
.section.mb10
%label.field.prepend-icon
=f.text_field :hex, id: "hex", class: "event-name gui-input br-light light", placeholder: 'Hex-значение цвета'
%label.field-icon{:for => "comment"}
%i.fa.fa-paint-brush
/ end section row section
%hr.short.alt
.section.row.mbn
.col-sm-8
%label.field.option.mt10
%input{:checked => "", :name => "info", :type => "checkbox"}
%span.checkbox>
Save Customer
%em.small-text.text-muted - A Random Unique ID will be generated
.col-sm-4
%p.text-right
=f.submit "Сохранить", class: "btn btn-primary"
/ end section
-if current_objects.respond_to?(:image)
.panel
.panel-heading
%span.panel-title Загруженные фотографии рецепта
.widget-menu.pull-right
%code.mr10.bg-light.dark.p3.ph5 фото можно удалить
.panel-body
=f.fields_for :pictures do |builder|
=image_tag builder.object.image.mini_thumb.url, class: "img-responsive thumbnail mr25 uzhin_doma_mini_thumb"
=builder.label :_destroy, 'Удалить фотографию?'
=builder.check_box :_destroy
Well, again a lot of HTML, but I will summarize the core points for you:
- First of all we build our form using triple nesting =form_for [:admin, :settings, current_objects] do |f|
- Now comes the most interesting part – surely your models will differ a bit. Maybe on has images to upload, the other doesn’t. One has a price tag, other don’t. Etc. and so on. Thus, we need to create an all-purpose-form, disabling fields when not required. This is done by respond_to? method. You can see it in this line -if current_objects.respond_to?(:picture) This basically means, that if there is no :picture method for current object, the block below won’t be executed. Nifty, eh?
- In my example every model has a field, called „name“, this is why I don’t check for it. All other fields are encapsulated in a respond_to? check.
Resume
With just a few methods – send and respond_to? you can create highly reusable partials where your maintain effort goes towards zero. Only one file for each action (index and edit/new) – truly amazing!
