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I am trying to figure out why the addLayer here isn't displaying the boxes that are present in the example shown below:

function($) {

    var box_extents = [
        [-10, 50, 5, 60],
        [-75, 41, -71, 44],
        [-122.6, 37.6, -122.3, 37.9],
        [10, 10, 20, 20]
        ];
    var map;

    map = new OpenLayers.Map({
        div: 'map',
        projection: new OpenLayers.Projection('EPSG:900913'),
        'displayProjection': new OpenLayers.Projection('EPSG:4326')
    });


    function init() {
        var ol_wms = new OpenLayers.Layer.WMS('OpenLayers WMS', 'http://vmap0.tiles.osgeo.org/wms/vmap0?', {
            layers: 'basic'
        });

        var boxes = new OpenLayers.Layer.Vector('Boxes');
        var i;

        for (i = 0; i < box_extents.length; i++) {
            ext = box_extents[i];
            bounds = OpenLayers.Bounds.fromArray(ext);

            box = new OpenLayers.Feature.Vector(bounds.toGeometry());
            boxes.addFeatures(box);
        }

        map.addLayers([ol_wms, boxes]);
        map.addControl(new OpenLayers.Control.LayerSwitcher());
        var sf = new OpenLayers.Control.SelectFeature(boxes);
        map.addControl(sf);
        sf.activate();
        map.zoomToMaxExtent();
    }

    init();
})(jQuery);

It works fine with addLayers in another example as displayed here:

(function($) {

        var map;

        function init() {
            map = new OpenLayers.Map('map');

            var layer = new OpenLayers.Layer.WMS( 'OpenLayers WMS',
                    'http://vmap0.tiles.osgeo.org/wms/vmap0', {layers: 'basic'} );
            map.addLayer(layer);

            // allow testing of specific renderers via '?renderer=Canvas', etc
            var renderer = OpenLayers.Util.getParameters(window.location.href).renderer;
            renderer = (renderer) ? [renderer] : OpenLayers.Layer.Vector.prototype.renderers;

            var vectorLayer = new OpenLayers.Layer.Vector('Simple Geometry', {
                styleMap: new OpenLayers.StyleMap({
                    'default': new OpenLayers.Style(null, {
                        rules: [
                            new OpenLayers.Rule({
                                symbolizer: {
                                    graphic: false,
                                    label: 'Label for invisible point',
                                    labelSelect: true,
                                    fontStyle: 'italic'
                                },
                                filter: new OpenLayers.Filter.Comparison({
                                    type: '==',
                                    property: 'topic',
                                    value: 'point_invisible'
                                })
                            }),
                            new OpenLayers.Rule({
                                symbolizer: {
                                    stroke: true,
                                    fill: true,
                                    label: 'Polygon with stroke and fill defaults'
                                },
                                filter: new OpenLayers.Filter.Comparison({
                                    type: '==',
                                    property: 'topic',
                                    value: 'polygon_defaults'
                                })
                            }),
                            new OpenLayers.Rule({
                                symbolizer: {
                                    stroke: true,
                                    fill: false,
                                    label: 'Point without fill',
                                    labelAlign: 'rb',
                                    fontColor: '#ff0000',
                                    fontOpacity: 0.4
                                },
                                filter: new OpenLayers.Filter.Comparison({
                                    type: '==',
                                    property: 'topic',
                                    value: 'point_nofill'
                                })
                            })
                        ]
                    })
                }),
                renderers: renderer
            });

            // create a point feature
            var point = new OpenLayers.Geometry.Point(-111.04, 45.68);
            var pointFeature = new OpenLayers.Feature.Vector(point);
            pointFeature.attributes = {
                topic: 'point_invisible'
            };

            // create a polygon feature from a linear ring of points
            var pointList = [];
            for(var p=0; p<6; ++p) {
                var a = p * (2 * Math.PI) / 7;
                var r = Math.random(1) + 1;
                var newPoint = new OpenLayers.Geometry.Point(point.x + 5 + (r * Math.cos(a)),
                                                             point.y + 5 + (r * Math.sin(a)));
                pointList.push(newPoint);
            }
            pointList.push(pointList[0]);

            var linearRing = new OpenLayers.Geometry.LinearRing(pointList);
            var polygonFeature = new OpenLayers.Feature.Vector(
                new OpenLayers.Geometry.Polygon([linearRing]));
            polygonFeature.attributes = {
                topic: 'polygon_defaults'
            };

            multiFeature = new OpenLayers.Feature.Vector(
                new OpenLayers.Geometry.Collection([
                    new OpenLayers.Geometry.LineString([
                        new OpenLayers.Geometry.Point(-105,40),
                        new OpenLayers.Geometry.Point(-95,45)
                    ]),
                    new OpenLayers.Geometry.Point(-105, 40)
                ]),
                {
                    topic: 'point_nofill'
                });

            map.addLayer(vectorLayer);
            vectorLayer.drawFeature(multiFeature);
            map.setCenter(new OpenLayers.LonLat(point.x, point.y), 4);
            vectorLayer.addFeatures([pointFeature, polygonFeature, multiFeature]);
            var select = new OpenLayers.Control.SelectFeature(vectorLayer, {
                selectStyle: OpenLayers.Util.extend(
                    {fill: true, stroke: true},
                    OpenLayers.Feature.Vector.style['select'])
            });
            map.addControl(select);
            select.activate();
        }

    init();
})(jQuery);

They are different enough that it's difficult to compare, but the formatting is pretty much the same: http://dev.openlayers.org/docs/files/OpenLayers/Map-js.html#OpenLayers.Map.addLayer

This is a GML layer is a vector layer subclass from what I've gathered: http://docs.openlayers.org/library/layers.html

share|improve this question
    
have you gone through the openlayer box example dev.openlayers.org/releases/OpenLayers-2.11/examples/boxes.html –  vinayan Apr 11 '12 at 4:47
    
Do you get any javascript errors? Also, make sure you have exactly one base layer, and to mark all others as overlays. –  relet Apr 11 '12 at 9:01
    
vinayan - I'm working from that and splitting it up into pieces in jsFiddle so that it is easier to see/manipulate. I've done this now with several of the dev examples from OpenLayers. @relet - I'm working from and there are no errors. I think I've got the base layer properly defined. –  Mike Gifford Apr 11 '12 at 13:55
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1 Answer

up vote 2 down vote accepted

I think you're having a problem of the function executing before the DOM objects are ready. I moved calling init in your first example to <body onload="init()"> and it started working fine. I also modified it a bit so it would play nice as a jQuery plugin using $.fn.extend({.

Update Per Comment:

This seems to be what you're looking for http://jsfiddle.net/rzwQr/9/

share|improve this answer
    
It could well be that the problem is that I am doing this within jsFiddle. I added your code (essentially) to here for comparison. I got essentially the same result. Note, I'm not sure why StackExchange just pulled out the javascript pane from the jsFiddle I and pasted into the window. I'd wanted to point to a real example. –  Mike Gifford Apr 11 '12 at 13:47
    
This works, but you still have a projection problem. –  CaptDragon Apr 11 '12 at 14:06
    
I fixed your projection problem by commenting out defined projection options. Check my latest update in my original answer. –  CaptDragon Apr 11 '12 at 14:10
    
Nice! Thanks @CaptDragon for your feedback. Posted the diff here to see what you changed to make it work - diffchecker.com/t4XGBO4 –  Mike Gifford Apr 11 '12 at 16:58
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