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
======================================================
