class Wice::GridRenderer

Adds a column with checkboxes for each record. Useful for actions with multiple records, for example, deleting selected records. Please note that action_column only creates the checkboxes and the ‘Select All’ and ‘Deselect All’ buttons, and the form itelf as well as processing the parameters should be taken care of by the application code.

• :param_name - The name of the HTTP parameter. The complete HTTP parameter is "#{grid_name}[#{param_name}][]". The default param_name is 'selected'.

• :html - a hash of HTML attributes to be included into the td tag.

• :select_all_buttons - show/hide buttons 'Select All' and 'Deselect All' in the column header. The default is true.

• :object_property - a method used to obtain the value for the HTTP parameter. The default is id.

You can hide a certain action checkbox if you add the usual block to g.action_column, just like with the g.column definition. If the block returns nil or false no checkbox will be rendered.

# File lib/wice/grid_renderer.rb, line 140
def action_column(opts = {}, &block)

  if @action_column_present
    raise Wice::WiceGridException.new('There can be only one action column in a WiceGrid')
  end

  options = {
    :param_name     => :selected,
    :html           => {},
    :select_all_buttons => true,
    :object_property => :id
  }

  opts.assert_valid_keys(options.keys)
  options.merge!(opts)
  @action_column_present = true
  column_processor_klass = Columns.get_view_column_processor(:action)

  @columns << column_processor_klass.new(@grid, options[:html], options[:param_name],
        options[:select_all_buttons], options[:object_property], @view, block)
end

Can be used to add HTML code (another row, for example) right after each grid row. Nothing is added if the block return false or nil.

# File lib/wice/grid_renderer.rb, line 401
def after_row(&block)
  @after_row_handler = block
end

Can be used to add HTML code (another row, for example) right before each grid row. Nothing is added if the block return false or nil.

# File lib/wice/grid_renderer.rb, line 407
def before_row(&block)
  @before_row_handler = block
end

The output of the block submitted to blank_slate is rendered instead of the whole grid if no filters are active and there are no records to render. In addition to the block style two other variants are accepted:

• g.blank_slate "some text to be rendered"

• g.blank_slate :partial => "partial_name"

# File lib/wice/grid_renderer.rb, line 421
def blank_slate(opts = nil, &block)
  if (opts.is_a?(Hash) && opts.has_key?(:partial) && block.nil?) || (opts.is_a?(String) && block.nil?)
    @blank_slate_handler = opts
  elsif opts.nil? && block
    @blank_slate_handler = block
  else
    raise WiceGridArgumentError.new("blank_slate accepts only a string, a block, or :template => 'path_to_template' ")
  end
end

Takes one argument and adds the <caption></caption> tag to the table with the argument value as the contents of <caption>.

# File lib/wice/grid_renderer.rb, line 120
def caption kaption
  @kaption = kaption
end

Defines everything related to a column in a grid - column name, filtering, rendering cells, etc.

column is only used inside the block of the grid method. See documentation for the grid method for more details.

The only parameter is a hash of options. None of them is optional. If no options are supplied, the result will be a column with no name, no filtering and no sorting.

• :name - Name of the column.

• :html - a hash of HTML attributes to be included into the td tag.

• :class - a shortcut for :html => {:class => 'css_class'}

• :attribute - name of a database column (which normally correspond to a model attribute with the same name). By default the field is assumed to belong to the default table (see documentation for the initialize_grid method). Parameter :model allows to specify another table. Presence of this parameter

  • adds sorting capabilities by this field

  • automatically creates a filter based on the type of the field unless parameter :filter is set to false. The following filters exist for the following types:

    • string - a text field

    • integer and float - two text fields to specify the range. Both limits or only one can be specified

    • boolean - a dropdown list with 'yes', 'no', or '-'. These labels can be changed in lib/wice_grid_config.rb.

    • date - two sets of standard date dropdown lists so specify the time range.

    • datetime - two sets of standard datetime dropdown lists so specify the time range. This filter is far from being user-friendly due to the number of dropdown lists.

• :filter - Disables filters when set to false. This is needed if sorting is required while filters are not.

• :filter_type - Using a column filter different from the default filter chosen automatically based on the data type or the :custom_filter argument. See lib/columns/column_processor_index.rb for the list of available filters.

• :ordering - Enable/disable ordering links in the column titles. The default is true (i.e. if :attribute is defined, ordering is enabled)

• :model - Name of the model class to which :attribute belongs to if this is not the main table.

• :table_alias - In case there are two joined assocations both referring to the same table, ActiveRecord constructs a query where the second join provides an alias for the joined table. Setting :table_alias to this alias will enable WiceGrid to order and filter by columns belonging to different associatiations but originating from the same table without confusion. See README for an example.

• :custom_filter - Allows to construct a custom dropdown filter. Depending on the value of :custom_filter different modes are available:

  • array of strings and/or numbers - this is a direct definition of possible values of the dropdown. Every item will be used both as the value of the select option and as its label.

  • Array of two-element arrays - Every first item of the two-element array is used for the label of the select option while the second element is the value of the select option

  • Hash - The keys of the hash become the labels of the generated dropdown list, while the values will be values of options of the dropdown list:

  • :auto - a powerful option which populates the dropdown list with all unique values of the field specified by :attribute and :model. :attribute throughout all pages. In other words, this runs an SQL query without offset and limit clauses and with distinct(table.field) instead of distinct(*)

  • any other symbol name (method name) - The dropdown list is populated by all unique value returned by the method with this name sent to all ActiveRecord objects throughout all pages. The main difference from :auto is that this method does not have to be a field in the result set, it is just some value computed in the method after the database call and ActiveRecord instantiation.

    But here lies the major drawback - this mode requires additional query without offset and limit clauses to instantiate all ActiveRecord objects, and performance-wise it brings all the advantages of pagination to nothing. Thus, memory- and performance-wise this can be really bad for some queries and tables and should be used with care.

    If the method returns a atomic value like a string or an integer, it is used for both the value and the label of the select option element. However, if the retuned value is a two element array, the first element is used for the option label and the second - for the value. Read more in README, section ‘Custom dropdown filters’

  • An array of symbols (method names) - similar to the mode with a single symbol name. The first method name is sent to the ActiveRecord object if it responds to this method, the second method name is sent to the returned value unless it is nil, and so on. In other words, a single symbol mode is a case of an array of symbols where the array contains just one element. Thus the warning about the single method name mode applies here as well.

    If the last method returns a atomic value like a string or an integer, it is used for both the value and the label of the select option element. However, if the retuned value is a two element array, the first element is used for the option label and the second - for the value. Read more in README, section ‘Custom dropdown filters’

• :boolean_filter_true_label - overrides the label for true in the boolean filter (wice_grid.boolean_filter_true_label in wice_grid.yml).

• :boolean_filter_false_label - overrides the label for false in the boolean filter (wice_grid.boolean_filter_false_label in wice_grid.yml).

• :allow_multiple_selection - enables or disables switching between single and multiple selection modes for custom dropdown boxes. true by default (see ALLOW_MULTIPLE_SELECTION in the configuration file).

• :filter_all_label - overrides the default value for BOOLEAN_FILTER_FALSE_LABEL ('--') in the config. Has effect in a column with a boolean filter or a custom filter.

• :detach_with_id - allows to detach the filter and render it after or before the grid with the grid_filter helper. The value is an arbitrary unique identifier of the filter. Read section 'Detached Filters' in README for details. Has effect in a column with a boolean filter or a custom filter.

• :in_csv - When CSV export is enabled, all columns are included into the export. Setting :in_csv to false will prohibit the column from inclusion into the export.

• :in_html - When CSV export is enabled and it is needed to use a column for CSV export only and ignore it in HTML, set this parameter to false.

• :helper_style - Changes the flavor of Date and DateTime filters. The values are:

  • :standard - the default Rails Date/DateTime helper

  • :calendar - a Javascript popup calendar control

• :negation - turn on/off the negation checkbox in string filters

• :auto_reload - a boolean value specifying if a change in a filter triggers reloading of the grid. Works with all filter types including the JS calendar, the only exception is the standard Rails date/datetime filters. The default is false. (see AUTO_RELOAD in the configuration file).

The block parameter is an ActiveRecord instance. This block is called for every ActiveRecord shown, and the return value of the block is a string which becomes the contents of one table cell, or an array of two elements where the first element is the cell contents and the second is a hash of HTML attributes to be added for the <td> tag of the current cell.

In case of an array output, please note that if you need to define HTML attributes for all <td>‘s in a column, use html. Also note that if the method returns a hash with a :class or 'class' element, it will not overwrite the class defined in html, or classes added by the grid itself (active-filter and sorted), instead they will be all concatenated: <td class="sorted user_class_for_columns user_class_for_this_specific_cell">

It is up to the developer to make sure that what in rendered in column cells corresponds to sorting and filtering specified by parameters :attribute and :model.

# File lib/wice/grid_renderer.rb, line 272
def column(opts = {}, &block)
  options = {
    :allow_multiple_selection   => Defaults::ALLOW_MULTIPLE_SELECTION,
    :ordering                   => true,
    :attribute                  => nil,
    :auto_reload                => Defaults::AUTO_RELOAD,
    :boolean_filter_false_label => NlMessage['boolean_filter_false_label'],
    :boolean_filter_true_label  => NlMessage['boolean_filter_true_label'],
    :class                      => nil,
    :name                       => '',
    :custom_filter              => nil,
    :detach_with_id             => nil,
    :filter_all_label           => Defaults::CUSTOM_FILTER_ALL_LABEL,
    :helper_style               => Defaults::HELPER_STYLE,
    :in_csv                     => true,
    :in_html                    => true,
    :model                      => nil,
    :negation                   => Defaults::NEGATION_IN_STRING_FILTERS,
    :filter                     => true,
    :filter_type                => nil,
    :table_alias                => nil,
    :html                       => {}
  }

  opts.assert_valid_keys(options.keys)
  options.merge!(opts)

  unless options[:model].nil?
    options[:model] = options[:model].constantize if options[:model].is_a? String
    raise WiceGridArgumentError.new("Option :model can be either a class or a string instance") unless options[:model].is_a? Class
  end

  if options[:attribute].nil? && options[:model]
    raise WiceGridArgumentError.new("Option :model is only used together with :attribute")
  end

  if options[:attribute] && options[:attribute].index('.')
    raise WiceGridArgumentError.new("Invalid attribute name #{options[:attribute]}. An attribute name must not contain a table name!")
  end

  if options[:class]
    Wice::WgHash.add_or_append_class_value!(options[:html], options[:class])
    options.delete(:class)
  end

  if block.nil?
    if ! options[:attribute].blank?
      block = lambda{|obj| obj.send(options[:attribute])}
    else
      raise WiceGridArgumentError.new(
        "Missing column block without attribute defined. You can only omit the block if attribute is present.")
    end
  end

  klass = Columns::ViewColumn
  if options[:attribute] &&
      col_type_and_table_name = @grid.declare_column(options[:attribute], options[:model],
        options[:custom_filter],  options[:table_alias], options[:filter_type])

    db_column, table_name, main_table = col_type_and_table_name
    col_type = db_column.type

    if options[:custom_filter]

      custom_filter = if options[:custom_filter] == :auto
        lambda{ @grid.distinct_values_for_column(db_column) } # Thank God Ruby has higher order functions!!!

      elsif options[:custom_filter].class == Symbol
        lambda{ @grid.distinct_values_for_column_in_resultset([options[:custom_filter]])}

      elsif options[:custom_filter].class == Hash
        options[:custom_filter].keys

        options[:custom_filter].to_a

      elsif options[:custom_filter].class == Array
        if options[:custom_filter].empty?
          []
        elsif Wice::WgEnumerable.all_items_are_of_class(options[:custom_filter], Symbol)
          lambda{ @grid.distinct_values_for_column_in_resultset(options[:custom_filter]) }

        elsif Wice::WgEnumerable.all_items_are_of_class(options[:custom_filter], String) || WgEnumerable.all_items_are_of_class(options[:custom_filter], Numeric)
          options[:custom_filter].map{|i| [i,i]}

        elsif Wice::WgEnumerable.all_items_are_of_class(options[:custom_filter], Array)
          options[:custom_filter]
        else
          raise WiceGridArgumentError.new(
            ':custom_filter can equal :auto, an array of string and/or numbers (direct values for the dropdown), ' +
            'a homogeneous array of symbols (a sequence of methods to send to AR objects in the result set to ' +
            'retrieve unique values for the dropdown), a Symbol (a shortcut for a one member array of symbols), ' +
            'a hash where keys are labels and values are values for the dropdown option, or an array of two-item arrays, ' +
            'each of which contains the label (first element) and the value (second element) for a dropdown option'
            )
        end
      end

      klass = Columns.get_view_column_processor(:custom)
    elsif options[:filter_type]
      klass = Columns.get_view_column_processor(options[:filter_type])
    else
      klass = Columns.get_view_column_processor(col_type)
    end # custom_filter

  end # attribute

  vc = klass.new(block, options, @grid, table_name, main_table, custom_filter, @view)

  vc.negation = options[:negation] if vc.respond_to? :negation=

  vc.filter_all_label = options[:filter_all_label] if vc.kind_of?(Columns.get_view_column_processor(:custom))
  if vc.kind_of?(Columns.get_view_column_processor(:boolean))
    vc.boolean_filter_true_label = options[:boolean_filter_true_label]
    vc.boolean_filter_false_label = options[:boolean_filter_false_label]
  end
  add_column(vc)
end

Can be used to add HTML code (calculation results, for example) after all rows. Nothing is added if the block return false or nil.

# File lib/wice/grid_renderer.rb, line 413
def last_row(&block)
  @last_row_handler = block
end

Optional method inside the grid block, to which every ActiveRecord instance is injected, just like column. Unlike column, it returns a hash which will be used as HTML attributes for the row with the given ActiveRecord instance.

Note that if the method returns a hash with a :class or 'class' element, it will not overwrite classes even and odd, instead they will be concatenated: <tr class="even highlighted_row_class_name">

# File lib/wice/grid_renderer.rb, line 395
def row_attributes(&block)
  @row_attributes_handler = block
end