Markers

Retrieving data

Markers are the core of the gmaps4rails gem which provides useful methods to retrieve all data from the model bearing acts_as_gmappable.

Say your User model contains acts_as_gmappable, then:

@markers = User.all.to_gmaps4rails    #@markers contain valid json to pass to the view

Or:

@markers = User.your_scope.to_gmaps4rails    #@markers contain valid json to pass to the view

Customize what is displayed

Info windows

Standard infowindows

To add an infowindow (visible when you click a marker), add this method in your model:

    def gmaps4rails_infowindow
      # add here whatever html content you desire, it will be displayed when users clicks on the marker
    end

The infowindow can contain whatever you want. Example:

    def gmaps4rails_infowindow
      "<img src=\"#{self.picture}\"> #{self.name}"
    end

If you want to use your a partial:

    def gmaps4rails_infowindow
      view = ActionView::Base.new(ActionController::Base.view_paths, {})
      class << view                                    # much hacky but useful
        include ApplicationHelper
      end
      processed_view = view.render :partial => "/path_to/my_template", :locals => { :object => self }
      processed_view.gsub(/\n/, '').gsub(/"/, '\"')    #adapt the gsub to what you need
    end 

Custom infowindows

Gmaps4rails now supports the InfoBox plugin you see here.

Here are the steps to reproduce the example in the source.

1. create your css class for the infobox (it's a div)

     .yellow { border: 1px solid black; margin-top: 8px; background: yellow; padding: 5px; }
   

2. Pass the options the plugin provides to gmaps4rails:

     Gmaps.map.infobox = function(boxText) {
      return {
         content: boxText
        ,disableAutoPan: false
        ,maxWidth: 0
        ,pixelOffset: new google.maps.Size(-140, 0)
        ,zIndex: null
        ,boxStyle: { 
          background: "url('http://google-maps-utility-library-v3.googlecode.com/svn/tags/infobox/1.1.5/examples/tipbox.gif') no-repeat"
          ,opacity: 0.75
          ,width: "280px"
           }
        ,closeBoxMargin: "10px 2px 2px 2px"
        ,closeBoxURL: "http://www.google.com/intl/en_us/mapfiles/close.gif"
        ,infoBoxClearance: new google.maps.Size(1, 1)
        ,isHidden: false
        ,pane: "floatPane"
        ,enableEventPropagation: false
     }};
   

3. call gmaps4rails

    <%= gmaps("markers" => {"data" => @json, "options" => {"custom_infowindow_class" => "yellow" } }) %> 
   

Add a title to your marker

To add a title (visible when you are over a marker), add this method in your model:

    def gmaps4rails_title
      # add here whatever text you desire
    end

Customize each marker

Include this method in your model to customize markers:

def gmaps4rails_marker_picture
 {
  "picture" => ,          # string, mandatory
   "width" =>  ,          # string, mandatory
   "height" => ,          # string, mandatory
   "marker_anchor" => ,   # array, facultative
   "shadow_picture" => ,  # string, facultative
   "shadow_width" => ,    # string, facultative
   "shadow_height" => ,   # string, facultative
   "shadow_anchor" => ,   # string, facultative
   "rich_marker" =>   ,   # html, facultative
                          # If used, all other attributes skipped except "marker_anchor". This array is used as follows:
                          # [ anchor , flat ] : flat is a boolean, anchor is an int. 
                          # See doc here: http://google-maps-utility-library-v3.googlecode.com/svn/trunk/richmarker/docs/reference.html 
 }
end

Note: the picture should be properly resized.

Example:

def gmaps4rails_marker_picture
  {
   "picture" => "/images/#{name}.png",
   "width" => "20",
   "height" => "20",
   "marker_anchor" => [ 5, 10],
   "shadow_picture" => "/images/morgan.png" ,
   "shadow_width" => "110",
   "shadow_height" => "110",
   "shadow_anchor" => [ 5, 10],
  }
end        

Create a list of your Markers in your html

in your model

def gmaps4rails_sidebar
  "<span class="foo">#{name}</span>" #put whatever you want here
end

In your view, you must add a <ul>

<ul id="markers_list">  </ul>

and call gmaps4rails properly:

<%= gmaps("markers" => {"data" => @json, "options" => {"list_container" => "markers_list" } }) %>

Creating your own json

Format

If you want to use your own json to initialize the map, create your json with the following attributes

    @markers = '[
             {"description": "", "title": "", "sidebar": "", "lng": "", "lat": "", "picture": "", "width": "", "height": ""},
             {"lng": "", "lat": "" }
            ]'

Only lat and lng are mandatory. (previous to 0.10.x they were latitude and longitude)

You can customize any single marker with the other attributes:

• picture, width and height are related to the marker

• description could contain whatever html you want to be displayed in the infowindow.

• sidebar contains the data to be displayed in the list of marker

Displaying your markers

Standard

In your view:

<%= gmaps("markers" => { "data" => @markers }) %>

Shortcut

In your view:

<%= gmaps4rails(@markers) %>

This displays the markers with auto-adjust option set to true. No other option could be passed this way.

Options

Options for markers are:

• marker_picture

• marker_width

• marker_length

• do_clustering, to cluster makers, default to false

• clusterer_gridSize, the more the quicker but the less precise, default to 50

• clusterer_maxZoom, define at which zoom level clusterer is disabled, default to 10

• draggable, allow drag markers, default to false

• randomize: false, Google maps can't display two markers which have the same coordinates. This randomizer enables to prevent this situation from happening.

• max_random_distance: 100 in meters. Each marker coordinate could be altered by this distance in a random direction

• list_container: null, if a string is passed, it will be assumed that it's the id of the <ul> in which you want the list of markers to be included. Define gmaps4rails_sidebar method in your model to customize what you want to be displayed in each <li>

• custom_clusterer_pictures: see help below

These options set default styling for your markers.

You can pass options this way:

<%= gmaps("markers" => { "data" => @markers, "options" => { "marker_picture" => your_pic, "marker_width" => 22, "marker_length" => 32 } }) %>

Customize

You can customize the pics used by the clusterer by setting the Gmaps.map.customClusterer js function in your code.

Here is an example:

Gmaps.map.customClusterer = function() {
  var url = "http://gmaps-utility-library.googlecode.com/svn/trunk/markerclusterer/1.0/images/";
  return [{
    url: url + 'heart30.png',
    height: 26,
    width: 30,
  },
  {
    url: url + 'heart40.png', 
    height: 35,
    width: 40,
  },
  {
    url: url + 'heart50.png',
    width: 50,
    height: 44,
  }];
}