This file contains the main API functions for OpenLayers and its sub-modules.
Also, see: THEMING.txt HOOKS.txt
Map Array API ======================================================
Maps are built using an array that looks like this:
$map = array( 'id' => _openlayers_create_map_id(), 'projection' => '900913', 'width' => 'auto', 'height' => '300px', 'center' => array( 'lat' => 40, 'lon' => 5, 'zoom' => 5, ), 'options' => array( 'displayProjection' => "4326", 'maxResolution' => 156543.0339, 'maxExtent' => array( 'left' => -20037508.34, 'bottom' => -20037508.34, 'right' => 20037508.34, 'top' => 20037508.34, ), ), 'controls' => array( 'LayerSwitcher' => TRUE, ), 'default_layer' => 'default_wms', 'layers' => array( 'default_wms' => array( 'id' => 'default_wms', 'type'=> 'WMS', 'name' => t('Default Open Layers WMS'), 'url' => 'http://labs.metacarta.com/wms/vmap0', 'params' => array( 'layers' => 'basic', ), 'options' => array(), 'events' => array( 'loadstart'=> array(), 'loadend' => array(), 'loadcancel' => array(), 'visibilitychanged' => array(), 'moveend' => array(), ), ), 'default_vector' => array( 'id' => 'default_vector', 'type' => 'Vector', 'name' => t('Default Vector'), 'options' => array(), 'events' => array( 'loadstart'=> array('yourModulesJSFunction'), ), ), ), 'behaviors' => array( 'behavior_id' => array( 'id' => 'behavior_id', 'type' => 'openlayers_behaviors_draw_features', 'feature_type' => 'point', 'layer' => 'default_vector', 'featureadded_handler' => array('openlayersCCKFeatureAdded'), 'featuremodified_handler' => array('openlayersCCKFeatureModified'), 'featureremoved_handler' => array('openlayersCCKFeatureRemoved'), ), 'zoom_to_layer' => array( 'id' => 'zoom_to_layer', 'type' => 'openlayers_behaviors_zoom_to_layer', 'layer' => 'default_vector', ), ), 'events' => array( 'addlayer' => array(''), ), );
API: Events ============ Events are currently supported for both the map object, and layer objects. To define an event you would first modify the map or layer's PHP array like so: 'default_vector' => array( 'events' => array( 'moveend' => array('customModuleLoadSomeData','customModuleDoSomethingElse'), 'zoomend' => array('customModuleLoadSomeData'), ), )
You would then be responsible for making sure that the customModuleLoadSomeData, and customModuleDoSomethingElse javascript functions are available. They would follow the following format:
function customModuleLoadSomeData(event){ var layer = event.layer;
//Our user has panned or zoomed the map. Let's load some more data into this layer .... }
Map Events ------------ preaddlayer addlayer removelayer changelayer movestart move moveend zoomend popupopen popupclose addmarker removemarker clearmarkers mouseover mouseout mousemove dragstart drag dragend changebaselayer
One-Time Map Events These events are triggered during the map building process, letting you execute javascript at various points while the map is being built. -------------------- beforeEverything -- Executed as soon as possible for each map. The OpenLayers map object is not yet built. beforeLayers -- After the map object is built, but before layers are created and added. beforeCenter -- Before the map is zoomed and centered. beforeControls -- Before controls are added to the map beforeEvents -- Before events are added to the map beforeBehaviors -- Before behaviors are triggered mapReady -- Last call
Layer Events ------------- beforefeatureadded beforefeaturesadded featureadded featuresadded beforefeatureremoved featureremoved featuresremoved beforefeatureselected featureselected featureunselected beforefeaturemodified featuremodified afterfeaturemodified refresh loadstart loadend loadcancel visibilitychanged moveend
API: Adding Features ====================
Although there are many paths to getting features onto maps via events, the API provides a standard way of adding features via the map array. To do so built a feature of the Vector type and add geometry, style, and attribute information like so:
'feature_example' => array( 'id' => 'feature_example', 'type' => 'Vector', 'name' => t('Default Vector'), 'options' => array(), 'events' => array(), 'features' => array( 'feature_1' => array( 'wkt' => 'POLYGON((1 1,5 1,5 5,1 5,1 1),(2 2, 3 2, 3 3, 2 3,2 2))', 'attributes' => array( 'name' => 'A Polygon with a hole in it', 'date' => 'December 24, 2004', 'author' => 'Santa Claus', ), 'style' => array( 'fillColor' => '#aa4400', 'fillOpacity' => '0.7', ), ), 'feature_2' => array( 'lat' => '40.123', 'lon' => '-20.123', 'attributes' => array( 'name' => 'A point', 'date' => 'December 24, 2004', 'author' => 'Rudolf', ), 'style' => array( 'externalGraphic' => 'http://openlayers.org/dev/img/marker.png', 'graphicWidth' => 21, 'graphicHeight' => 25, 'graphicXOffset' => 10, 'graphicYOffset' => 10, ), ), ), ),
Default style properties ------------------------ fillColor: "#ee9900" fillOpacity: 0.4 strokeColor: "#ee9900" strokeOpacity: 1 strokeWidth: 1 strokeLinecap: "round" [butt | round | square] strokeDashstyle: "solid" [dot | dash | dashdot | longdash | longdashdot | solid] pointRadius: 6 pointerEvents: "visiblePainted" cursor: ""
Other style properties that have no default values -------------------------------------------------- externalGraphic, graphicWidth, graphicHeight, graphicOpacity, graphicXOffset, graphicYOffset, graphicName, display
API: Behaviors ==============
Behaviors add interactivity to maps.
API: Layers ===========
How to add layers to maps.
Adding pre-defined layers -------------------------
Example: NASA Layers
$map['layers'] = array ( 'openlayers_layers_nasa_global_mosaic', 'openlayers_layers_nasa_daily_planet', 'openlayers_layers_nasa_blue_marble', );
Adding layers the long way --------------------------
Example: NASA Layers
$map['layers'] = array ( 'openlayers_layers_nasa_global_mosaic' => array( 'id' => openlayers_layers_nasa_global_mosaic, 'type' => 'WMS', 'name' => 'NASA Global Mosaic!', 'projection' => array('4326'), 'baselayer' => true, 'url' => 'http://t1.hypercube.telascience.org/cgi-bin/landsat7', 'params' => array( 'layers' => 'landsat7', ), ); ) 'openlayers_layers_nasa_daily_planet', 'openlayers_layers_nasa_blue_marble', );
Some of those parameters are used across all layer types, and some are specific to the 'WMS' layer type. id -- Unique ID of the layer. This should be the same as the array key type -- Layer type. This defines which handler is repsonsible for processing this layer. Examples include WMS, WFS, Vector, KML. name -- The name of the layer presented to the user projection -- An array with a list of compatible projections. If projection is not specified, then it is assumed that this layer is compatible with all projections. baselayer -- Should this be considered a baselayer or an overlay? If baselayer is not speficied, then baselayer may be true of false depending on the layer type. url -- WMS SPECIFIC - defines the WMS URL params -- WMS SPECIFIC - associative array of parameters to pass to the WMS query
API: Defining New Reusable Layers =================================
API: Defining New Reusable Layer Types ======================================
API: Defining New Reusable Behaviors ====================================
API: predefined Layer Types and how to use them ====================================================== Vector ------ This is the most fundemental layer type and is used for most overlays.
WMS --- http://en.wikipedia.org/wiki/Web_Map_Service
WFS --- http://en.wikipedia.org/wiki/Web_Feature_Service
KML --- http://en.wikipedia.org/wiki/KML
XYZ ---
Google, VirtualEarth, and Yahoo -------------------------------- These layer types have a very limited way that they can be reused. I beleive all those ways are already implemented. So don't use these, use the implemented layer definitions!
API: predefined Behaviors and how to use them ======================================================
