[mapserver-users] [EXTERNAL] Re: Clickable label

Tue Sep 9 08:04:11 PDT 2014

I would recommend the UTF Grid approach.

http://mapserver.org/development/rfc/ms-rfc-93.html or

On 9/9/14, 6:35 AM, "Basques, Bob (CI-StPaul)"
<bob.basques at ci.stpaul.mn.us> wrote:

>All,
>
>It's probably not the cleanest way to approach it, but maybe a straight
>imagemap type approach.   You use the four corners of the label bounding
>poly and send as an imagemap or json set or id query.
>
>I think the bounding polys need to somehow be thought of as a ad-hoc data
>layer themselves.  Is there a way of sub-selecting feature constructs
>(that were originated by mapserver, like centroids are, into a reusable
>(on the fly) dataset?
>
>My immediate thoughts were to use a clientside imagemage (which is passe
>these days) and that is where the translation occurs for the bounding
>boxes, via the imagemap generation.
>
>bobb
>________________________________________
>From: Lime, Steve D (MNIT)
>Sent: Monday, January 20, 2014 9:43 AM
>To: Basques, Bob (CI-StPaul); wiltomap; mapserver-users at lists.osgeo.org
>Subject: RE: [mapserver-users] Clickable label
>
>That or a UTFGrid. I don't believe that support (in master) handles
>labels but maybe it could. In UTFGrid context you wouldn't want to render
>characters anyway, only the bounding polygons. However, because the grid
>is rendered at a lower resolution than the related map label placement
>consistency might be the issue. --Steve
>________________________________________
>From: Basques, Bob (CI-StPaul)
>Sent: Friday, January 10, 2014 6:15 PM
>To: Lime, Steve D (MNIT); wiltomap; mapserver-users at lists.osgeo.org
>Subject: RE: [mapserver-users] Clickable label
>
>Steve,
>
>I've been thinking on this thread since it started, I wonder, could you
>use a imagemap template from Mapserver, but populate it with the Label
>bounding polygons?
>
>bobb
>
>
>________________________________________
>From: mapserver-users-bounces at lists.osgeo.org
>[mapserver-users-bounces at lists.osgeo.org] on behalf of Lime, Steve D
>(MNIT) [Steve.Lime at state.mn.us]
>Sent: Friday, January 10, 2014 4:14 PM
>To: wiltomap; mapserver-users at lists.osgeo.org
>Subject: Re: [mapserver-users] Clickable label
>
> This can't be done with stock MapServer. Labels are dynamic by nature
>and are the product of a map raw while queries work off the base data.
>The bridge between the map and a query is a conversion from pixels to map
>coordinates based on map size and extent.
>
>You might be able to pull this off using MapScript. For a query you'd
>have to do things in two stages:
>
>  1) Draw the map (in memory) based on the map the user interacted with
>(same extent, size and set of layers) so that a label cache is created.
>  2) Search the label cache based on the query point and based on that
>pull the appropriate feature.
>
>I don't know if step 2 is feasible or not. You used to be able to loop
>through it, not sure about now.
>
>There might be other ways using an image where you render text and label
>backgrounds using the same color, a color that you could map back to a
>feature id. The map would basically contain label polygons in a raster
>you could, in turn, query that raster using point and retrieve a feature
>id. I have doubts that you could match the first image to the second so
>this would be a huge long shot.
>
>Steve
>
>-----Original Message-----
>From: mapserver-users-bounces at lists.osgeo.org
>[mailto:mapserver-users-bounces at lists.osgeo.org] On Behalf Of wiltomap
>Sent: Friday, January 10, 2014 2:17 AM
>To: mapserver-users at lists.osgeo.org
>Subject: [mapserver-users] Clickable label
>
>Hello all,
>
>I have to display labels instead of points on a layer. The labels rely on
>an attribute value. I would like to click on the label to make an
>attribute windows open up. So far, no problem with mapfile
>configuration...
>
>The only thing is that the attribute window opens up when I click right
>in the middle of the label. I can use TOLERANCEUNITS and TOLERANCE
>parameters in the mapfile to enlarge the clickable area BUT this means
>that I can also click next to the label and get the attribute window,
>which I don't want to...
>
>My purpose is to get the attribute window whereever I click on the label
>(any part of it) and not if I click next to it. Would you think about a
>solution to that ?
>
>I enclose a scrennshot of the mapfile I have worked out so far.
>
>
>Many thanks in advance,
>
>Thomas
>
>
><http://osgeo-org.1560.x6.nabble.com/file/n5097281/mapfile_label.jpg>
>
>
>
>--
>View this message in context:
>http://osgeo-org.1560.x6.nabble.com/Clickable-label-tp5097281.html
>Sent from the Mapserver - User mailing list archive at Nabble.com.
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