wiki:PHPMapscriptAddLayerQueryReproject

Add Layer, Query and Reproject

Example 1

Here's a small example which:

  • opens a mapfile
  • adds a new layer
  • queries new layer
  • reprojects output map
  • draws and saves to file

Example based on http://dl.maptools.org/dl/omsug/osgis2004/php_mapscript_mum2.ppt in response to http://n2.nabble.com/Problems-with-MapScript-and-setProjection-tt2291579.html#none

Contributed by Tom Kralidis.

<?php

// load mapscript
dl("php_mapscript.so");

// add map
$map = ms_newMapObj("config.map");

// add new layer to map
$layer = ms_newLayerObj($map);
$layer->set("name", "foo");
$layer->set("status", MS_ON);
$layer->set("data", "path/to/file.shp");
$layer->set("type", MS_LAYER_POINT);
$layer->setProjection("init=epsg:4326");
$layer->set("template", "ttt");
$layer->set("dump", "true");

// add new class to new layer
$class = ms_newClassObj($layer);
$class->set("name", "foo");

// add new style to new class
$style = ms_newStyleObj($class);
$style->set("symbol", 2);
$style->set("size", 8);
$style->color->setRGB(255, 0, 0);

// create new rect to query against the new layer
$rect = ms_newRectObj();
$rect->setExtent(-95, 40, -50, 60);

// query new layer
$layer->queryByRect($rect);

// set projection of output map
$map->setProjection("init=epsg:42304", MS_TRUE);
// draw
$image=$map->drawQuery();
$image->saveImage("/tmp/out.png");

?>

Example 2

The example below works under MapServer 5.2.1 (tested under Fedora 10). Contributed by Tim Wood.

<?PHP

/**
 * Code to create a map from a shapefile
 * and then (optionally) reproject the whole thing
 *
 * If you just want to look at the reprojection stuff, start
 * with the "reproject (if needed) and draw" section at the end.
 * The rest
 *
 * Created by Tim Wood from code and input
 * by Tom Kralidis [Ontario], Pietro Gianninni and Stephen Jones.
 *
 * No copyright restrictions
 */


// ---------------------------
// Configuration
// aka set a bunch of variables and load the mapscript extension
//

// Where my key directories are located
$doc_root = '/var/www/html';
$rel_path = "example1/round2";

$base_path = "$doc_root/$rel_path";


// An empty map file
$base_map = "$base_path/data/empty.map";   // just the words MAP and END on dif. lines... really

// The data I'm using
$shape_path    = "$base_path/data/zcta/zt08_d00_shp/";    // a goofy path I'm too lazy to fix
$shape_file = "gfsa000b06a_e";                            // works with or w/o the extension
$shape_file_projection = "+proj=longlat +datum=NAD83";

// The Extents (area) I want in latitude, longitude
list( $ex0, $ex1, $ex2, $ex3 ) = array(-140, 40, -50, 55 );

// Describe the rest of my output
$output_projection = '';
$output_projection = "+proj=tcc +lon_0=90w +ellps=GRS80";
$output_file_rel = "output/index2.png";
$output_file_path = "$base_path/$output_file_rel";
list($output_width, $output_height ) = array( 600, 500 );

// Load MapScript extension
if (!extension_loaded("MapScript"))  dl('php_mapscript.'.PHP_SHLIB_SUFFIX);




// ---------------------------
// Function(s)
//

/**
 * Reproject a $map from $shape_file_projection to $output_projection
 */
function reproject_map( &$map, $shape_file_projection, $output_projection ) {
    $origProjObj = ms_newProjectionObj( $shape_file_projection );
    $newProjObj = ms_newProjectionObj( $output_projection );

    $oRect = $map->extent;
    $oRect->project( $origProjObj, $newProjObj );
    $map->setExtent( $oRect->minx, $oRect->miny, $oRect->maxx, $oRect->maxy );
    $map->setProjection( $output_projection  );
}



// ---------------------------
// The Main Code
//

// add map
$map = ms_newMapObj( $base_map );
$map->set( 'name', 'my_map' );    // If we're using a blank map file, give it a name

// Set the extent
$map->setExtent( $ex0, $ex1, $ex2, $ex3 );

// Set the shapepath
$map->set( 'shapepath', $shape_path );
// Set the output format and size
$map->selectOutputFormat( 'png' );
$map->setSize( $output_width, $output_height );

// add new layer to map
$layer = ms_newLayerObj($map);
$layer->set("name", "foo");
$layer->set("status", MS_ON);
$layer->set("data", $shape_file );
$layer->set("type", MS_SHAPE_POLYGON );
$layer->setProjection( $shape_file_projection );
$layer->set("template", "ttt");    // hide errors that appear iff $output_projection is set?
$layer->set("dump", "true");

// add new class to new layer
$class = ms_newClassObj($layer);
$class->set("name", "foo");

// add new style to new class
$style = ms_newStyleObj($class);
$style->color->setRGB(255, 0, 0);
$style->outlinecolor->setRGB( 128,128,128 );

// reproject (if needed) and draw
if( $output_projection != '' ) {
    reproject_map( $map, $shape_file_projection, $output_projection );
    $image = $map->drawQuery();
} else {
    // draw
    $image = $map->draw();
}



// ---------------------------
// Output the image
//

$image->saveImage( $output_file_path );

?>
<html>
<body>
    <img src="<?PHP print $output_file_rel; ?>">
</body>
</html>

back to PHPMapScript

Last modified 10 years ago Last modified on Feb 10, 2009 11:44:23 AM