PHP Mapscript

1
PHP Mapscript

• Yewondwossen Assefa
• Daniel Morissette
• DM Solutions Group Inc.

2
Contents

• Introduction to PHP Mapscript
• Object Model
• Application building
• Some Advanced features
• Questions

3
What is PHP Mapscript

• one flavour of MapScript (Perl, Python, Java
  versions exist also)
• custom extension for PHP
• abstracts the MapServer object model in PHP
  constructs

4
Why do we use PHP Mapscript

• Because it provides the ability to do things that
  can't be done in MapServer's CGI mode
• Dynamic layers
• Customized navigation
• On the fly classification
• Enhanced legends and layer controls
• Advanced query capabilities
• PHP is an advanced open source programming
  language with significant modules such as GD,
  dbase, odbc

5
Object Model

• Cover the main objects found in php/mapscript and
  how to access members and functions of some of
  the objects
• Php Mapscript "Jacket" on top of mapserver
  library
• Most of the mapserver elements accessible through
  php/mapscript
• Documentation at http//mapserver.gis.umn.edu/do
  c/phpmapscript-class-guide.html

6
Object Model global view
7
Map Object
8
Access to the Map object

• How to create a new map object
• oMap ms_newMapObj("mymapfile.map")
• oMap ms_newMapObj("")
• How to access members of the object (case
  sensitive)
• echo oMap-gtname
• How to access functions of the object (case
  insensitive)
• oLayer oMap-gtgetlayer(0)

9
Access to the Map object

• How to modify member of the object
• oMap-gtset("name", "a new name")
• common mistake oMap-gtname "a new name"
  
• How to access the sub objects
• oMap-gtweb-gtset(...)

10
Layer Object
11
Access to the Layer object

• Accessing layers through the map object
• nLayers oMap-gtnumlayers
• for (i0 iltnLayers i)
• oLayer oMap-gtgetlayer(i)
• echo oLayer-gtname .
• ..
• Creating a new layer
• oLayer ms_newLayerObj(oMap)
• oLayer-gtset("name", "my_new_layer")
• oLayer-gtset("type", MS_LAYER_LINE)
• //can be used to create a layer from another
  layer
• oLayer ms_newLayerObj(oMap, srclayer)

12
Layer object

• Diffrent types of layers predefined constants
• MS_LAYER_POINT,
• MS_LAYER_LINE,
• MS_LAYER_POLYGON
• MS_LAYER_RASTER
• MS_LAYER_ANNOTATION
• MS_LAYER_QUERY
• MS_LAYER_CIRCLE
• MS_LAYER_TILEINDEX

13
Class and Style

• Accessing classes through the layer object
• nClass oLayer-gtnumclass
• for (i0 iltnClass i)
• oClass oMap-gtgetclass(i)
• echo oClass-gtname
• ...
• Creating a new class
• oClass ms_newClassObj(oLayer)
• oLayer-gtset("name", "my_new_layer")
• ...

14
Class and Style

• Creating a new style
• oStyle ms_newStyleObj(oClass)
• oStyle-gtset("symbol", 1) ...
• Will be covered with examples in Advanced
  Features section

15
Shapefile Object
16
Shapefile manipulation

• Open existing shapefile
• //first argument is the shapefilename without
  the extension
• //second argument (type) is set to -1 to open an
  existing file oShapeFile ms_newShapefileObj("my
  _shapefile", -1)
• Creating a shape object
• //The argument represents the type of shape
  object to be created.
• //Valid types are MS_SHAPE_POINT,
  MS_SHAPE_LINE, MS_SHAPE_POLYGON
• oShape ms_newShapeObj(MS_SHP_POINT)

17
Shapefile manipulation

• Creating a line/Point object
• oLine ms_newLineObj()
• oPoint ms_newPointObj()
• Will be covered with examples in Advanced
  features section

18
Application Building Contents

• Drawing a Map
• Adding a Key Map
• Adding a Scalebar
• Adding Navigation Tools (zoom in, )
• Navigation using the Key Map
• Adding a Legend
• HTML Legend
• Query

19
Prepare the application structure

• Directory structure of the application (data, map
  file, html, symbol file )
• URL to access the application
• Temporary files

20
The whole application

• http//http//localhost/mum2_php_mapscript/index.p
  html
• The directory /ms4w/apps/mum2_php_mapscript/
• Data, htdocs, etc

21
Application structure

• Index(X).phtml and step(X).php
• Separate HTML from the PHP code
• Phtml file contains already calls to PHP
  functions. PHP functions are there but are empty.

22
Step1 General

• http//localhost/mum2_php_mapscript/index1.phtml
• /ms4w/apps/mum2_php_mapscript/htdocs/Step1.php
• /ms4w/apps/mum2_php_mapscript/htdocs/index1.phtml

23
Step2 Adding a map

• Loading the php mapscript module
• Loading the map file
• Draw map function
• function DrawMap()
• img GLOBALS"goMap"-gtdraw()
• url img-gtsaveWebImage()
• nWidth GLOBALS"goMap"-gtwidth
• nHeight GLOBALS"goMap"-gtheight
• echo"ltINPUT TYPEimage SRC".url." BORDER0
  WIDTH\"".
• nWidth."\" HEIGHT\"".nHeight."\"
  NAMEMAINMAPgt\n"

24
Step3 Keymap

• Draw a key map
• function DrawKeyMap()
• img GLOBALS"goMap"-gtdrawreferencemap()
• url img-gtsaveWebImage()
• echo "ltINPUT TYPEimage SRCurl BORDER0
  NAMEKEYMAPgt\n"

25
Step4 Scalebar

• Draw scalebar
• function DrawScaleBar()
• img GLOBALS"goMap"-gtdrawScaleBar()
• url img-gtsaveWebImage()
• echo"ltIMG SRCurl BORDER0gt\n"

26
Step5 adding Navigation (zoom in)

• Know what type of navigation is selected
• _GET (_POST) super global associative array
  for HTTP GET
• Preserve current map extents, width and height

27
Step 5 adding Navigation (zoom in)

• Top of the file
• aVars (sizeof(_POST) gt 0) ? _POST
  (sizeof(_GET) gt 0) ? _GET array()
• ProcessURLArray( aVars )
• In DrawMap function
• echo"ltINPUT TYPEimage SRC".url." BORDER0
  WIDTH\"".
• nWidth."\" HEIGHT\"".nHeight."\"
  NAMEMAINMAPgt\n"
• echo "ltINPUT TYPEHIDDEN NAMEMINX VALUE\"".
• GLOBALS"goMap"-gtextent-gtminx."\"gt\n"
• echo "ltINPUT TYPEHIDDEN NAMEMINY VALUE\"".
• GLOBALS"goMap"-gtextent-gtminy."\"gt\n"
• echo "ltINPUT TYPEHIDDEN NAMEMAXX VALUE\"".
• GLOBALS"goMap"-gtextent-gtmaxx."\"gt\n"
• echo "ltINPUT TYPEHIDDEN NAMEMAXY VALUE\"".
• GLOBALS"goMap"-gtextent-gtmaxy."\"gt\n"

28
Step 5 adding Navigation (zoom in)

• function ProcessURLArray( aVars)
• //set up the previous extents
• oExt GLOBALS"goMap"
• fMinX isset(aVars"MINX") ?
  aVars"MINX" oExt-gtextent-gtminx
• fMinY isset(aVars"MINY") ?
  aVars"MINY" oExt-gtextent-gtminy
• fMaxX isset(aVars"MAXX") ?
  aVars"MAXX" oExt-gtextent-gtmaxx
• fMaxY isset(aVars"MAXY") ?
  aVars"MAXY" oExt-gtextent-gtmaxy
• GLOBALS"goMap"-gtsetextent( fMinX, fMinY,
  fMaxX, fMaxY )
• //some short cuts
• fWidthPix GLOBALS"goMap"-gtwidth
• fHeightPix GLOBALS"goMap"-gtheight

29
Step5 adding Navigation (zoom in)

• //process commands
• if (isset(aVars"CMD"))
• //determine where to navigate to.
• nX isset(aVars"MAINMAP_x") ?
  intval(aVars"MAINMAP_x")
• 
  fWidthPix/2.0
• nY isset(aVars"MAINMAP_y") ?
  intval(aVars"MAINMAP_y")
• 
  fWidthPix/2.0
• if (isset(aVars"MAINMAP_x")
  isset(aVars"MAINMAP_y"))
• oPixelPos ms_newpointobj()
• oPixelPos-gtsetxy(nX, nY)
• oGeorefExt ms_newrectobj()
• oGeorefExt-gtsetextent(fMinX,
  fMinY, fMaxX, fMaxY)
• if (aVars"CMD" "ZOOM_IN")

30
Step 6 All Nav. tools

• Modify function ProcessURLArray to look for other
  CMD values
• .
• else if (aVars"CMD" "ZOOM_OUT")
• GLOBALS"goMap"-gtzoompoint(-2,
  oPixelPos, fWidthPix,
• fHeightPix,
  oGeorefExt)
• else if (aVars"CMD" "RECENTER")
• GLOBALS"goMap"-gtzoompoint(1,
  oPixelPos, fWidthPix,
• fHeightPix,
  oGeorefExt)
• else if (aVars"CMD"
  "ZOOM_FULL")
• GLOBALS"goMap"-gtsetextent(GLOB
  ALS"gfMinX",GLOBALS"gfMinY",
• 
  GLOBALS"gfMaxX",GLOBALS"gfMaxY")

31
Step7 Keep selected tool

• GLOBALS"gszCurrentTool" "ZOOM_IN"
• function ProcessURLArray( aVars)
• //record the current command
• GLOBALS"gszCurrentTool"
  (isset(aVars"CMD")) ? aVars"CMD"
  "ZOOM_IN"
• function IsCurrentTool( szTool )
• return (strcasecmp(GLOBALS"gszCurrentTool",
  szTool) 0)

32
Step8 KeyMap navigation

• Inside function ProcessURLArray
• else if (isset(aVars"KEYMAP_x")
  isset(aVars"KEYMAP_y"))
• oRefExt GLOBALS"goMap"-gtreference-gtext
  ent
• nX intval(aVars"KEYMAP_x")
• nY intval(aVars"KEYMAP_y")
• fWidthPix doubleval(GLOBALS"goMap"-gtre
  ference-gtwidth)
• fHeightPix doubleval(GLOBALS"goMap"-gtr
  eference-gtheight)
• nGeoX Pix2Geo(nX, 0, fWidthPix,
  oRefExt-gtminx, oRefExt-gtmaxx, 0)
• nGeoY Pix2Geo(nY, 0, fHeightPix,
  oRefExt-gtminy, oRefExt-gtmaxy, 1)
• fDeltaX (fMaxX - fMinX) / 2.0
• fDeltaY (fMaxY - fMinY) / 2.0
• GLOBALS"goMap"-gtsetextent(nGeoX -
  fDeltaX, nGeoY - fDeltaY,
• nGeoX
  fDeltaX, nGeoY fDeltaY)

33
Step9 draw legend

• function DrawLegend()
• img GLOBALS"goMap"-gtdrawLegend()
• url img-gtsaveWebImage()
• echo"ltIMG SRCurl BORDER0gt\n"

34
Step10 HTML Legend

• Docs at http//mapserver.gis.umn.edu/doc40/html-
  legend-howto.html
• The HTML legend is an alternative to the
  traditional GIF legend in MapServer
• Set TEMPLATE "legend.html in the map file
  inside the legend object
• leg_layer_html orderascending opt_flag15 lttr
  height20pxgt
• lttd align"center"gtltinput type"checkbox"
  name"legendlayername" value"leg_layer_name"
  if namelayer_status opereq value1CHECKED/if
  if namelayer_status opereq value2CHECKED/if
  gtlt/tdgt
• lttdgtnbspltimg src"leg_icon width20
  height13" width20 height13gtnbsplt/tdgt
• lttdgtltfont face"Arial, Helvetica, sans-serif"
  size"3"gtmetadata nameDESCRIPTIONlt/fontgtlt/tdgt
• lt/trgt
• /leg_layer_html

35
Step 10 HTML Legend

• Call function DrawHTMLLegend() in index10.phtml
• function DrawHTMLLegend()
• echo "lttable cellspacing0 cellpadding0gt"
• echo "lttr bgcolor\"E2EFF5\"gt\n"
• echo "lttdgtlt/tdgt\n"
• echo "lttdgtlt/tdgt\n"
• echo "lt/trgt\n"
• echo GLOBALS"goMap"-gtprocessLegendTemplate(
  array() )
• echo "lttrgt\n"
• echo "lttdgtltinput type\"image\"
  src\"./images/icon_update.png\" width\"20\"
  height\"20\"gtlt/tdgt\n"
• echo "lttd colspan2gtltfont face\"Arial,Helveti
  ca,sans-serif\" size\"2\"gtUpdatelt/tdgt\n"
• echo "lt/trgt\n"
• echo "lt/tablegt"

36
Step11 Layer control

• Inside function ProcessURLArray
• //process layer visibility
• if (isset(_GET"legendlayername"))
• for( i0 iltGLOBALS"goMap"-gtnumlayers
  i )
• oLayer GLOBALS"goMap"-gtgetLayer(
  i)
• if (in_array( oLayer-gtname,
  _GET"legendlayername" ))
• oLayer-gtset( "status", MS_ON )
• else
• oLayer-gtset( "status", MS_OFF )

37
Step12 Query

• Set templates in a layer
• Function ProcessURLArray
• .
• else if (aVars"CMD" "QUERY")
• nGeoX Pix2Geo(nX, 0,
  fWidthPix,
• fMinX, fMaxX, 0)
• nGeoY Pix2Geo(nY, 0,
  fHeightPix,
• fMinY, fMaxY, 1)
• oGeo ms_newPointObj()
• oGeo-gtsetXY(nGeoX, nGeoY)
• // Use '_at_' to avoid warning if
  query found nothing
• _at_GLOBALS"goMap"-gtqueryByPoint(
  oGeo, MS_MULTIPLE, -1)
• GLOBALS"gShowQueryResults"
  TRUE

38
Step12 Query

• GLOBALS"gShowQueryResults" FALSE
• function DrawMap()
• if (GLOBALS"gShowQueryResults")
• img GLOBALS"goMap"-gtdrawQuery()
• else
• img GLOBALS"goMap"-gtdraw()
• function DrawQueryResults()
• if (!GLOBALS"gShowQueryResults")
• echo "nbsp"
• else
• sTemplate GLOBALS"goMap"-gtprocessque
  rytemplate(array(), 0)
• echo sTemplate

39
Advanced Features

• Creating a new Shapefile
• Adding a new layer dynamically
• Adding classification dynamically

40
Creating a shape file

• Files advanced.phtml and advanced.php
• function AddDynamicLayer()
• //Creating the shapefiles
• oMap GLOBALS"goMap"
• szFileName oMap-gtweb-gtimagepath .
  uniqid("")
• oShapFile ms_newShapeFileObj(szFileName,
  MS_SHP_POINT)
• //create a new DBF attached with few
  attributes
• hDbf dbase_create(szFileName.".dbf",
• array(array("POP_RANGE",
  "N", 5, 0),
• array("NAME", "C",
  50, 0),
• array("CAPITAL",
  "N", 5, 0)))
• if (!hDbf)
• return

41
Creating a shape file

• open the original dbf file szOrginalDbfName
  "../data/canada_cities.dbf" hOrigDbf
  dbase_open(szOrginalDbfName, 0) if
  (!hOrigDbf) return nRecords
  dbase_numrecords(hOrigDbf) for (i1
  iltnRecords i) //retreive
  field attributes aRecord
  dbase_get_record_with_names(hOrigDbf, i)
  dfLat floatval(aRecord"LAT")
  dfLong floatval(aRecord"LONG")
  nPopRange intval(aRecord"POP_RANGE")
  szName strval(aRecord"NAME")
  nCapital intval(aRecord"CAPITAL")

42
Creating a shape file

• //create a point for each record and add it to
  the shapefile
• oShp ms_newShapeObj(MS_SHP_POINT)
• oLine ms_newLineObj()
• oLine-gtaddXY(dfLong, dfLat)
• oShp-gtadd( oLine )
• oShapFile-gtaddShape(oShp)
• //add a record to the DBF
• aAttValues0 nPopRange
• aAttValues1 szName
• aAttValues2 nCapital
• dbase_add_record(hDbf, aAttValues)
• oShp-gtfree()
• dbase_close(hOrigDbf)
• dbase_close(hDbf)
• oShapFile-gtfree()

43
Adding a new layer and styling it

• function CreateLayer(szDataName)
• oMap GLOBALS"goMap"
• //create layer and set members
• oLayer ms_newLayerObj(oMap)
• oLayer-gtset("name", "canada_cities")
• oLayer-gtset("status", MS_ON)
• oLayer-gtset("data", szDataName)
• oLayer-gtset("type", MS_LAYER_POINT)
• //projection is latlong
• oLayer-gtsetProjection("initepsg4326")
• oLayer-gtset("labelitem", "NAME")
• oLayer-gtset("classitem", "CAPITAL")

44
Adding a new layer and styling it

• //Country capital
• //create class
• oClass ms_newClassObj(oLayer)
• oClass-gtset("name", "Capital")
• oClass-gtsetexpression("/1/")
• //create style
• oStyle ms_newStyleObj(oClass)
• oStyle-gtset("symbol", 2)
• oStyle-gtset("size", 8)
• oStyle-gtcolor-gtsetRGB(255, 0, 0)
• //set label object
• oClass-gtlabel-gtset("font",
  "fritqat-italic")
• oClass-gtlabel-gtset("type", MS_TRUETYPE)
• oClass-gtlabel-gtset("size", 8)
• oClass-gtlabel-gtcolor-gtsetRGB(255, 0 , 0)
• oClass-gtlabel-gtset("position", MS_AUTO)

45
Adding a new layer and styling it

• //provincial capitals
• oClass ms_newClassObj(oLayer)
• oClass-gtset("name", "Provincial Capital")
• oClass-gtsetexpression("/23/")
• oStyle ms_newStyleObj(oClass)
• oStyle-gtset("symbol", 7)
• oStyle-gtset("size", 6)
• oStyle-gtcolor-gtsetRGB(0, 0, 0)
• //set label object
• oClass-gtlabel-gtset("font", "fritqat")
• oClass-gtlabel-gtset("type", MS_TRUETYPE)
• oClass-gtlabel-gtset("size", 8)
• oClass-gtlabel-gtcolor-gtsetRGB(0, 0 , 0)
• oClass-gtlabel-gtset("position", MS_AUTO)
• oClass-gtlabel-gtset("partials", MS_FALSE)