| Version 1 (modified by , 15 years ago) ( diff ) |
|---|
query_points42.pl
#!/usr/bin/perl
# This has been tested with mapserver 4.2 beta3. I found that Perl mapscript4.0.2 was not quite ready for prime
# time. Missing methods: class->getStyle(), colorObj support, etc. It illustrates some of the changes needed to
# adapt a mapscript3.6 application to mapscript4.2. Thanks to Sean Giles for all his work on mapscript.
########################
# This is an example of creating a layer of point objects (actually buoys in the Gulf of Maine, U.S.) It should be
# easily adaptable to any set of points. It creates the points as features in the layer which means that they
# can still be retrieved using $layer->queryByPoint() even though no shape file or database connection exists
# for them.
# In this revised edition:
# a) the points are drawn using $point->draw(). This allows us to do a getClass() and getStyle() for each point
# and set style values such as $class->{style}{size} for each point.
# b) We call addFeature() so that the layer is queryable, which is the main point.
# c) We use a numeric key value as the $shape->{index} which maps to our "database". This will be returned by
# queryByPoint().
# d) No need to call $layer->draw() since we already called $point->draw(). Thus the features serve as
# an invisible layer just for querying.
# Author: Eric Bridger eric@gomoos.org eric@maine.com
# Date:
# This has been tested with mapserver 4.2 beta3. It does not work with mapserver4.0.2
########################
use strict;
use mapscript42;
use CGI ":cgi";
$ENV{MS_ERRORFILE} = '/tmp/mapserver4.log';
my $q = new CGI;
my $msg = '';
# A hash of points. First field is the key value used in addFeature() and returned by queryByPoint().
# This could come from any external database, etc.
my %points = (
10202 => {'longitude' => -67.0173,
'latitude' => 44.8911,
'size' => 5,
'label' => 'one',
},
20103 => {'longitude' => -66.0146,
'latitude' => 45.2045,
'size' => 10,
'label' => 'two',
},
30105 => {'longitude' => -68.3578,
'latitude' => 43.7148,
'size' => 12,
'label' => 'three',
},
40102 => {'longitude' => -66.5528,
'latitude' => 43.6243,
'size' => 18,
'label' => 'four',
},
50105 => {'longitude' => -68.9983,
'latitude' => 44.0555,
'size' => 20,
'label' => 'five',
},
60102 => {'longitude' => -67.8800,
'latitude' => 43.4900,
'size' => 10,
'label' => 'six',
},
70104 => {'longitude' => -70.5665,
'latitude' => 42.5185,
'size' => 10,
'label' => 'seven',
},
80103 => {'longitude' => -70.4278,
'latitude' => 43.1807,
'size' => 10,
'label' => 'eight',
},
90104 => {'longitude' => -68.1087,
'latitude' => 44.1058,
'size' => 8,
'label' => 'nine',
},
100202 => {'longitude' => -70.0578,
'latitude' => 43.5673,
'size' => 15,
'label' => 'ten',
},
);
my $image_name = sprintf("tmp/%0.10d",rand(1000000000)) . ".png";
# see points42.map
my $map = new mapscript42::mapObj("points42.map");
if(!$map){
warn "New mapObj() error: $mapscript42::ms_error->{message}\n";
}
# Get symbol indexes from map's symbolset
my $circle_idx = $map->{symbolset}->index("circle");
my $plus_idx = $map->{symbolset}->index("plus");
# Colors have changed in 4.2. No longer just an index, $clr_index = $map->addColor() is gone.
# You can also use $styleOjb->{color}->setRGB() and $class->{label}->{color}->setRGB();
my $blue = new mapscript42::colorObj(0,0,255);
my $red = new mapscript42::colorObj(255,0,0);
my $black = new mapscript42::colorObj(0,0,0);
# Create a point object representing the mouse click on the map.
my ($x, $y) = get_click($q, $map);
my $click_pt = undef;
if($x != 0 && $y != 0){
$click_pt = new mapscript42::pointObj();
$click_pt->{x} = $x;
$click_pt->{y} = $y;
}
# create an image for drawing.
my $img = $map->draw();
if(!$img){
warn "prepareImage() error: $mapscript42::ms_error->{message}\n";
}
my $layerObj = undef;
# Add points as Features to the point layer.
$layerObj = $map->getLayerByName('points');
# Queries will return index into this array.
foreach my $point_id (keys %points){
my $point = new mapscript42::pointObj();
$point->{x} = $points{$point_id}{longitude};
$point->{y} = $points{$point_id}{latitude};
# Features require shape objects, which require lines, so create a single point line.
my $line = new mapscript42::lineObj();
$line->add($point);
my $shp = new mapscript42::shapeObj($mapscript42::MS_SHAPE_POINT);
$shp->add($line);
#$shp->setBounds();
# Don't set any text, $point->draw() will draw the text.
#$shp->{text} = $point_id;
# set the shape index to our database key value.
# the $shp->{index} can be any NUMERIC value. If our database key values were alphanumeric
# we would need to use a lookup array and set $shp-{index} to 0,1,2,...
# queryByPoint() results will return this value, but it must be numeric.
$shp->{index} = $point_id;
$layerObj->addFeature($shp);
# we only have one class in this layer.
my $class = $layerObj->getClass(0);
# TWO APPROACHES illustrated here.
# NEW SYTLE OBJ
#my $style = new mapscript42::styleObj();
# OR
# EXISTING STYLE OBJ: This picks up defaults from map file e.g. black outline color
my $style = $class->getStyle(0);
# Add new style.
#my $style = new mapscript42::styleObj($class);
# point size based on our "database"
$style->{size} = $points{$point_id}{size};
if($point_id == 40102){
$style->{symbol} = $plus_idx;
}else{
$style->{symbol} = $circle_idx;
}
#$style->{symbol} = $plus_idx;
# COLORS
# just to illustrate assigning a reference to a colorObj.
my $color = $red;
if($point_id == 20103){
$color = $black;
}
$style->{color} = $color;
# since this is a STYLE from the map file we don't need this.
# it's in the map file.
$style->{outlinecolor} = $black;
$class->{label}->{color} = $blue;
$point->draw($map, $layerObj, $img, undef, $points{$point_id}{label});
# NEW STYLE must REMOVE if you inserted it.
#$class->removeStyle(0);
}
# Query based on the mouse click point.
if($click_pt){
$msg .= "<p>\n";
# this is un-needed.
$layerObj = $map->getLayerByName('points');
if($layerObj->queryByPoint($map,$click_pt,$mapscript42::MS_SINGLE,0)){
$msg .= "No Points found<br>\n";
}else{
# In 4.2 $layerObj-{resultcache} is no longer used.
# use $num_results = $layerObj->getNumResults() then
# foreach my $i (0 .. $num_results-1){
# my $rslt = $layerObj->getResult($i);
#}
# we only expect one result.
my $rslt = $layerObj->getResult(0);
# this is the numeric value we used for the shape passed to addFeature() above.
my $point_id = $rslt->{shapeindex};
$msg .= "Click found point: $point_id.<br>\n";
$msg .= "name is: $points{$point_id}{label}.<br>\n";
$msg .= "size is: $points{$point_id}{size}.<br>\n";
$msg .= "lat: $points{$point_id}{latitude} long: $points{$point_id}{longitude}.<br>\n";
}
$msg .= "</p>\n";
}
# display the click point
if($click_pt){
$layerObj = $map->getLayerByName('click');
$click_pt->draw($map, $layerObj, $img, undef, "Click");
}
$map->drawLabelCache($img);
$img->save($image_name);
# NOTA BENA Deconstructors (~) have been created for all mapscript objects. Don't call $imgObj->free().
# It will be removed, but now causes core dump.
#$img->free();
# Output the HTML form and map
print $q->header();
print $q->start_html(-title=>'MapServer4.2 - Dynamic Points', -bgcolor=>"#ffffff");
print "<form name=\"pointmap\" action=\"points42.cgi\" method=\"GET\">\n";
print "<table border=\"1\" cellpadding=\"5\" cellspacing=\"2\">\n";
print "<tr>\n";
print "<td>\n";
print "<input border=\"2\" type=\"image\" name=\"img\" src=\"$image_name\">\n";
print "</td>\n";
print "</tr>\n";
print "</table>\n";
print "</form>\n";
print "$msg<br>\n";
print "<p><br><br><br></p>\n";
print $q->end_html();
# translate mouse click x,y into map longitude, latitude based on map extent. This is based on set_extent() in
# mapquakes.pl
sub get_click {
my ($q, $map) = @_;
my ($x, $y, $cx, $cy) = (0,0,0,0);
my $minx = $map->{extent}->{minx};
my $miny = $map->{extent}->{miny};
my $maxx = $map->{extent}->{maxx};
my $maxy = $map->{extent}->{maxy};
if($q->param('img.x')) { # Make sure we got a click
$x = $q->param('img.x');
$y = $q->param('img.y');
$cx = ($maxx-$minx)/($map->{width}-1); # calculate cellsize in x and y
$cy = ($maxy-$miny)/($map->{height}-1);
$x = $minx + $cx*$x; # change x,y from image to map coordinates
$y = $maxy - $cy*$y;
}
return ($x, $y);
}
points42.map
MAP
NAME "points42"
STATUS ON
EXTENT -71.5 39.5 -63.0 46.0
SIZE 504 385
IMAGETYPE PNG
UNITS DD
PROJECTION
"proj=latlong"
END
OUTPUTFORMAT
NAME PNG
DRIVER "GD/PNG"
MIMETYPE "image/png"
# 24bit
IMAGEMODE RGB
# 8 bit psuedo color
#IMAGEMODE PC256
#EXTENSION "png"
END
SYMBOL
TYPE ELLIPSE
NAME "circle"
POINTS 1 1 END
FILLED TRUE
END
SYMBOL
TYPE VECTOR
NAME "plus"
POINTS .5 0 .5 1 -99 -99 0 .5 1 .5 END
END
LAYER
NAME "points"
TYPE POINT
STATUS ON
TOLERANCE 10
# Need fake template for querys to work
TEMPLATE "bogus.html"
CLASS
NAME "buoy"
STYLE
SYMBOL "circle"
SIZE 0
COLOR 0 255 0
OUTLINECOLOR 0 0 0
END
LABEL
COLOR 255 0 0
TYPE BITMAP
SIZE MEDIUM
POSITION AUTO
PARTIALS FALSE
BUFFER 2
END # end of label
END
PROJECTION
"proj=latlong"
END
END
LAYER
NAME "click"
TYPE POINT
STATUS ON
CLASS
NAME "click"
STYLE
SYMBOL "plus"
SIZE 6
COLOR 0 0 0
END
LABEL
TYPE BITMAP
SIZE TINY
COLOR 0 0 0
POSITION AUTO
PARTIALS FALSE
BUFFER 1
END
END
END
END
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