Adding a shape to a map dynamically

[Ben Tuttle]

I was planning on using ruby/mapscript. I am trying to build a small
interface to be viewed through a web browser. I've considered some of
the clients, but they tend to be more than I need, so I was thinking
I'd just build it with mapscript. Your suggestion of adding a point to
a layer sounds about like what I want to do. The only difference would
be that we have quite a few mapfiles so ideally I'd like to add the
layer dynamically as well, rather than add it to every mapfile. I have
been playing with the code below, but it doesn't show the box. Any
chance this is a limitation of adding the layer dynamically or am I
just implementing it incorrectly?

bbox = Mapscript::ShapeObj.new(2)
p1 = Mapscript::PointObj.new(Request['West'], Request['North'])
p2 = Mapscript::PointObj.new(Request['East'], Request['North'])
p3 = Mapscript::PointObj.new(Request['East'], Request['South'])
p4 = Mapscript::PointObj.new(Request['West'], Request['South'])
line = Mapscript::LineObj.new
line.add(p1)
line.add(p2)
line.add(p3)
line.add(p4)
line.add(p1)
bbox.add(line)

map = Mapscript::MapObj.new "#{map_path}countries.map"
bboxLayer = Mapscript::LayerObj.new(map)
bboxLayer.name = "bbox"
bboxLayer.type = 2
bboxLayer.status = 0
bboxLayer.addFeature(bbox)
cls = Mapscript::ClassObj.new(bboxLayer)
style = Mapscript::StyleObj.new()
color = Mapscript::ColorObj.new()
color.red = 107
color.green = 158
color.blue = 160
style.color = color
cls.insertStyle(style)

image = Mapscript::ImageObj.new(width=800,height=382)
image=map.draw()
bboxLayer.draw(map, image)
image.save("#{image_path}temp.png")
image_url = image.imageurl


On 3/9/07, Steve Lime <Steve.Lime at dnr.state.mn.us> wrote:
> What technology options do you have? Are you using MapScript, the CGI, any particular client?
>
> Many of the clients have their own abilities here.
>
> With MapScript I would define your presentation layer ahead of time in the mapfile, build a shapeObj and add it to the layer, then draw the layer or map.
>
> With the CGI you can define inline features at runtime. Here's an example (w/a point):
>
>   http://maps.dnr.state.mn.us/cgi-bin/mapserv410?map=/usr/local/mapserver/apps/waters/csg/reference.map&mode=map&layer=site&map_site_feature_points=342601.236380747+5193344.65190589
>
> There is a presentation layer called "site" that I add one point to. Same approach would apply to a polygon, just more points (first=last).
>
> Steve
>
> >>> On 3/9/2007 at 10:26 AM, in message
> <259e26270703090826n232af065ndf0436ec711e2489 at mail.gmail.com>, Ben Tuttle
> <funkbucket at GMAIL.COM> wrote:
> > Hi all-
> > I'd like to overlay a polygon on my map based on coordinates input
> > form a form. I'm wondering what the best way would be to do this.
> > My first thoughts were to either add a layer dynamically as an inline
> > feature or perhaps to create a shapeObj (not sure if this will work as
> > expected) and draw it. Any thoughts on the best way to do something
> > like this?
>
>