Controlling classitems through PHP? (Tanzanian protected areas)

[Ragnvald]

After trying this, my experience is that I can control classes which already
have been defined in the .map-file. Fair enough, but when operating with
24*22 squares totalling 528 squares (from one shapefile) I have two
problems:

o Making the basic mapfile with 528 classes sounds like a lot of manual
work. Perhaps I could do this through PHP. The procedure you illustrated
involves changing an existing class. Adding classes with php?

o But then, wouldn't 528 classes exceed the max nr of classes? (Think I read
this somewhere on the list)

On a later stage I will have to handle a grid with more squares (240*220
totalling 52.800 squares). The plan is to make a system where animal
sightings information is allocated to the squares (size 5*5 km). For example
we could end up with a map of green squares where we have had observations
of certain animals (presence maps). We could also invert the maps and use
them for planning new surveys.

One solution suggested below by Kristjan is to draw the objects within a
shape-file individually. This sounds like a good idea since we would not
have to operate with classes (which is not really necessary in this case).

But how is this done - by using PHP?


Ragnvald

PS I guess the code I will develop based on this will be made available as
an example with some dummy data, so the information will not be lost on me
:-)

-----Original Message-----
From: Kristjan Annus [mailto:kristjan at tarkvarastuudio.ee]
Sent: 18. mars 2005 00:02
To: Ragnvald Larsen
Subject: Re: [UMN_MAPSERVER-USERS] Controlling classitems through PHP?
(Tanzanian protected areas)

This is some fragment of the code witch I use to color the bus line
depending of is it an express bus or not:

$oCurrLayer = $map->getlayerbyname("Lines")

$classObj = $oCurrLayer->getClass( 0);
$styleobj = $classObj->getstyle(0);
$styleobj->color->setRGB( 0, 0, 250);

I assume that you could get the Parks layer and change all the classes
in that layer according to the information in the database. getClass(0)
gives you
the first class in your map file (Serengeti), getClass(1) second one and
so on.

It is allso possible to use just one class and loop through the objects
in the shapefile and color the class  by database information and then
draw the particular shape.

Kristjan

>No, not new layers and classes. I would like to extend the ones I already
>have. Eg change this one:
>
>CLASS
>  COLOR 210 210 210
>  SYMBOL 0
>  EXPRESSION "Ikorongo"
>  NAME "Ikorongo"
>END
>
>Let's imagine I start with all the parks in a neutral grey like the one
>above. Then the user wants to know how elephants are distributed in between
>the parks by visual inspection. Here at TAWIRI we just happen to have such
>numbers in a database, but we currently make the maps manually. With
numbers
>from several years and also for other species than the elephant it will be
a
>very big job to make all the maps - of which some probably not will be
>interesting anyway.
>
>So, I really would like to control the color of the specific classes by
>using PHP.
>
>Making new classes like the one above would also be very useful.
>
>The next thing is that I also have a shapefile with 22x24 squares (half
>degree sizes) with unique names. Used the fishnet functionality to make the
>grid squares. It is similar to the ggrid currently used by the Tanzania
Bird
>Atlas project (http://tanzaniabirdatlas.com/). The Birdatlas has been
>subject to Mapserver earlier:
>
>http://www.gis.unbc.ca/courses/geog413/projects/2004/hoffman/
>
>Based on our data I also hope to be able to make a presence/absence map by
>highlighting the grid squares. This problem is a bit like the one above,
but
>the number of objects to be controlled is big.
>
>
>Ragnvald
>
>
>-----Original Message-----
>From: Kristjan Annus [mailto:kristjan at tarkvarastuudio.ee]
>Sent: 17. mars 2005 18:00
>To: Ragnvald Larsen
>Subject: Re: [UMN_MAPSERVER-USERS] Controlling classitems through PHP?
>(Tanzanian protected areas)
>
>Do you mean, how to create new layers and classes in PHP, so that you
>dont have the pre-defined classes in the map file?
>
>Kristjan
>
>
>
>>Hello,
>>    the control structure around is really not a problem. The problem is
>>how to do with PHP what I manage to do with the code in my request.
>>
>>Ragnvald
>>
>>-----Original Message-----
>>From: Kristjan Annus [mailto:kristjan at tarkvarastuudio.ee]
>>Sent: 17. mars 2005 16:43
>>To: Ragnvald; MAPSERVER-USERS at LISTS.UMN.EDU
>>Subject: Re: [UMN_MAPSERVER-USERS] Controlling classitems through PHP?
>>(Tanzanian protected areas)
>>
>>Hi,
>>
>>I am a little bit confused what you actually want to do? If you have the
>>data witch you want to publish in database, then
>>you could for example loop through the records and draw each one of them
>>to the map with PHP functions and change the
>>color or appearance of the current shape before you draw this particular
>>shape. In this case you could use different pre-made
>>classes in your map file and change the classitem of the shape.
>>How the actual code should look like depends witch database you are
>>using and how the datastructure is organized.
>>I can make you a better example if I could have more information.
>>
>>But generally it could be something like this:
>>
>>do (with every shape on the database) {
>>// gather the points to the shape from your database (some loop required
>>I assume):
>>
>>$line = ms_newLineObj();
>>do ( ... ) {
>>$point = ms_newPointObj();
>>$point->setXY( $myrow["koord1"], $myrow["koord2"]);
>>$line->add( $point);
>>}
>>
>>// draw the shape to the map ( the $classitem variable could be set
>>before by some information from your database)
>>$pind=ms_newShapeObj( 2);
>>$pind->add($line);
>>$lshape->draw( $map, $layer, $image, $classitem, $tekst);
>>
>>}
>>
>>Kristjan
>>
>>
>>
>>
>>
>>>I have a layer of Tanzanian protected areas (National parks, Game
>>>Reserves, Conservation areas, etc). My goal is to be able to control
>>>the visual appearances of the separate parks based on numerical data
>>>in an animal survey database using PHP.
>>>
>>>I am really struggling with this and have not been able to figure it
>>>out. I have done several searches, and to be honest working with
>>>classes through PHP is a bit new to me. If I manage to do this it will
>>>be VERY helpful for us here at TAWIRI.
>>>
>>>The planned script should generate different maps for different
>>>estimated species concentrations in these protected areas. The first
>>>step is to be able to control the different parks appearances by
>>>referring to their names. (Currently the developed solution will only
>>>be for testing purposes and internal use at my department.)
>>>
>>>This is what I can do by using a simple map-file:
>>>
>>>http://www.mindland.com/test/tanzania_parks_pres_1.gif
>>>
>>>The code for the "Parks" layer is like this:
>>>
>>>LAYER
>>>
>>>NAME "Parks"
>>>
>>>TYPE POLYGON
>>>
>>>STATUS ON
>>>
>>>DATA "TZ_PAs_2002_Poly"
>>>
>>>PROJECTION
>>>
>>>"proj=latlong"
>>>
>>>"ellps=GRS80"
>>>
>>>"datum=NAD83"
>>>
>>>END
>>>
>>>CLASSITEM 'NAME'
>>>
>>>CLASS
>>>
>>>COLOR 190 190 190
>>>
>>>SYMBOL 0
>>>
>>>EXPRESSION "Serengeti"
>>>
>>>NAME "Serengeti"
>>>
>>>END
>>>
>>>CLASS
>>>
>>>COLOR 210 210 210
>>>
>>>SYMBOL 0
>>>
>>>EXPRESSION "Ikorongo"
>>>
>>>NAME "Ikorongo"
>>>
>>>END
>>>
>>>CLASS
>>>
>>>COLOR 220 220 220
>>>
>>>SYMBOL 0
>>>
>>>EXPRESSION "Grumeti"
>>>
>>>NAME "Grumeti"
>>>
>>>END
>>>
>>>CLASS
>>>
>>>COLOR 220 220 220
>>>
>>>SYMBOL 0
>>>
>>>EXPRESSION "Masawa"
>>>
>>>NAME "Masawa"
>>>
>>>END
>>>
>>>CLASS
>>>
>>>COLOR 220 220 220
>>>
>>>SYMBOL 0
>>>
>>>EXPRESSION "Ngorongoro"
>>>
>>>NAME "Ngorogoro"
>>>
>>>END
>>>
>>>END
>>>
>>>END
>>>
>>>The question is then how to control the CLASSITEM color appearance and
>>>also selection of which classitems to show - through PHP. In the end I
>>>will use database queries, but for now I will be happy to do this by
>>>hard coding it in PHP. I am able to do changes on the other parks (not
>>>displayed as classitems). This code is added before the map is drawn:
>>>
>>>$layerObj = $map->getlayerbyname("Parks");
>>>
>>>$class = ms_newClassObj($layerObj);
>>>
>>>$style = ms_newStyleObj($class);
>>>
>>>$style->color->setRGB(200,200,0);
>>>
>>>Resulting image is then:
>>>
>>>http://www.mindland.com/test/tanzania_parks_pres_2.gif
>>>
>>>Suggestions and references to relevant postings would be fine. I re
>>>
>>>Ragnvald Larsen
>>>
>>>Geographer / data systems developer
>>>
>>>Conservation Information and Monitoring Unit,
>>>
>>>Tanzania Wildlife Researc Institute,
>>>
>>>Tanzania
>>>
>>>
>>>
>>>
>>>
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