<br><br><div class="gmail_quote">2009/10/3 Martin Kofahl <span dir="ltr"><<a href="mailto:m.kofahl@gmx.net">m.kofahl@gmx.net</a>></span><br><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
What is your (and other MapServer devs') opinion about a having a spatial access control system inside MapServer?<br>
<br></blockquote><div><br>Martin,<br><br>I admit I haven't studied all aspects of this proposal, but it looks like as it would be an example of an "extension layer" addressed by one of my previous RFCs,<br>
<a href="http://mapserver.org/development/rfc/ms-rfc-22a.html">http://mapserver.org/development/rfc/ms-rfc-22a.html</a><br><br>(Note: The title of this RFC doesn't completely reflect the proposed concept, the feature cache would only be just one simple usage example of that. I should probably rename this RFC to something like: "Support to implement extension layers").<br>
<br>In this case the the layer would be defined in a cascaded fashion in the map file. The outer layer would be able override the vtable functions of the inner layer, therefore a subset of the features could also be hidden according to a custom logic when displaying the whole layer. I this regard, it wouldn't be required to define 2 sibling layers (which is quite annoying here), the outer layer would contain the select shape, and the vtable functions could eventually implement reading the env variables as required. <br>
<br>In case if this common infrastructure would exist in MapServer, then you'd only require to write your custom layer data provider (ie. the vtable functions of a new layer type) which could eventially be a plugin (independent from the mapserver codebase).<br>
<br>By all means, my preference here would be to establish a common infrastucture where various special requirements could easily be implemented without affecting the core funtionality too much. Your intents seems to be just a simple use case of the need to extend/override the functionality of the existing layer data sources which should be handled in a common way.<br>
<br>At that time when this proposal have been created (along with working patches, see the corresponding ticket) I couldn't gather any community support to make it realized in the development version. At this time I'm not too keen to spend more efforts on this, however I would personally support any effort to implement a concept which could be extensible such way. <br>
<br><br>Best regards,<br><br>Tamas<br><br><br><br> </div></div>