Map object by name#50
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Adds the object_by_name method to the Tiled::Map class as discussed.
added the following exceptions, which are raised in the object_by_name of the Tiled::Map class ObjectLayerNotFound and ObjectNameNotFound
| #then returns that object | ||
| def object_by_name(layer_name, object_name) | ||
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| named_layer = @object_groups.reject do | layer | |
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It is better to use object_groups method instead of instance variable, because it can be uninitialized if map file doesn't have object layers.
object_group is a Tiled::Layers instance, so you can work with it like with map.layers:
named_layer = object_groups[layer_name]As a bonus it will cache reference to this layer.
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| raise ObjectLayerNotFound, "The object layer \"#{layer_name}\" was not found in map \"#{@path}\"" if named_layer.nil? | ||
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| the_object = named_layer.objects.reject do | object | |
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named_layer will be a Tiled::ObjectLayer and has find_by_name method, so you can use it to find object by name:
the_object = named_layer.find_by_name(object_name)It will always return first object or nil if object is not found.
| class MapNotFound < Error; end | ||
| class TilesetNotFound < Error; end | ||
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| #added the following exceptions, which are raised in the object_by_name of the Tiled::Map class |
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I think class names are self-explanatory so no need for comment here.
| return height * tileheight | ||
| end | ||
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| #gets the first object layer with the passed name of `layer_name` |
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I would prefer to format comments in yard syntax, you can check the example in the lib/tiled/layers.rb file.
| #gets the first object layer with the passed name of `layer_name` | ||
| #then looks in that layer for the first object that has the name `object_name` | ||
| #then returns that object | ||
| def object_by_name(layer_name, object_name) |
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I'm not sure about passing a layer name there, because this action can be performed in this way:
map.layers[layer_name].find_by_name(object_name)But it would be more valuable if the user will be able to find an object without passing layer_name:
map.object_by_name(object_name)What do you think about this?
| layer.name != layer_name | ||
| end.first | ||
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| raise ObjectLayerNotFound, "The object layer \"#{layer_name}\" was not found in map \"#{@path}\"" if named_layer.nil? |
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Right now all methods return nil if desired object/tile is not found, it is better to save this approach.
But I think it is good to have a method that raises errors in case an object is not found. I love the approach when the regular method is returning nil and the bang method raises errors:
def object_by_name(object_name)
# return nil and not raise errors
end
def object_by_name!(object_name)
raise SomeError if the_object.nil?
endDo you think it makes sense?
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Yeah, I think that makes sense, staying consistent will keep people from getting confused. I will look into it.
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I think with the release of v0.4.0 this can be closed for now.
2 participants
As discussed. Added a method to the map class that allows you to look up an object by name, given a specific name for a map/object layer.
If the object layer named can't be found, it will raise an
ObjectLayerNotFounderror. giving the name of the object layer passed and which map (via the path) couldn't find it.if that doesn't fail, the method then checks for an object in the layer with the passed name.
if the object can't be found, it will raise an
ObjectNameNotFounderror, giving the name of the object that couldn't be found on the passed layer name.