[OpenLayers-Users] FW: getting GeoJSON features in my search

[Gery .]

Hello, after several days checking on google I've found no examples to keep 
working on this, I'd appreciate if someone could point me to some examples, the 
problem is basically that the whole GeoJSON output is passed to OL no matter 
what I write in the search button, I don't get that part, I'd appreciate some 
support on this, thank you.


From: gameji...@hotmail.com
To: openlayers-users@lists.osgeo.org
Subject: getting GeoJSON features in my search
Date: Tue, 25 Sep 2012 22:32:12 +0000








After googleing for a while and reading the OL documentation, I don't 
understand well how the filterToParams in OpenLayers.HTTP protocol should work, 
what I'm trying to do is to get the GeoJSON features that matches my search 
using the following code:

[code]
Ext.onReady(function() {
    var map = new OpenLayers.Map();
    var osm = new OpenLayers.Layer.OSM(
        "OSM"
    );
    map.addLayer(osm);

    var mappanel = new GeoExt.MapPanel({
        region:"center",
        height: 400,
        width: 600,
        map: map,
        title: 'A Simple GeoExt Map'
    });

    var layerList = new GeoExt.tree.LayerContainer({
        text: 'All Layers',
        layerStore: mappanel.layers,
        leaf: false,
        expanded: true
    });

    var layerTree = new Ext.tree.TreePanel({
        title: 'Map Layers',
        maxWidth: 500,
        region: "east",
        collapsible: true,
        collapsed: true,
        root: layerList
    });

    var features = [];
    var vecLayer = new OpenLayers.Layer.Vector("Results");
    var select = new GeoExt.grid.FeatureSelectionModel();

    // define the data source
    var protocol = new OpenLayers.Protocol.HTTP({
        url: 
'http://localhost/postgis_geojson.php?geotable=boreholes_point_wgs84&geomfield=geom',
/*        params: {
            outputFormat: "json"
        },
        filterToParams: function (filter, params) {
            if (filter.type === name)
            return params;
        },*/
        format: new OpenLayers.Format.GeoJSON({
            ignoreExtraDims: true,
            'internalProjection': new OpenLayers.Projection("EPSG:900913"),
            'externalProjection': new OpenLayers.Projection("EPSG:4326")
        })
    });
/*    protocol.read({
        callback: function(r){
            console.log("received featured: " + r.features);
        }
    });*/

    formPanel = new GeoExt.form.FormPanel({
        title: "Place Name Search",
        height: 150,
        region: "north",
        protocol: protocol,
        items: [{
            xtype: "textfield",
            width: 200,
            name: "station__like",
            fieldLabel: "station <br />(use * and . for wildcards)",
            allowBlank: false,
            minLength: 1
        }],
        listeners: {
            actioncomplete: function(form, action) {
                features = action.response.features;
                store.loadData(features);
                vm=map.getLayersByName("Results");
                if(vm.length===0){
                    vecLayer = new OpenLayers.Layer.Vector("Results");
                    map.addLayer(vecLayer);
                    store.bind(vecLayer);
                    select.bind(vecLayer);
                }
            }
        },
        buttons: [{text: 'search',
            handler: function(){
                formPanel.search();
            }
        }],
        keys: [{ key: [Ext.EventObject.ENTER], 
            handler: function() {
                formPanel.search();
            }
        }]
    });
    
    var cols = [ {name: 'station', type: 'string'},
                {name: 'survey', type: 'string'},
                {name: 'type', type: 'string'},
                {name: 'w_depth_m', type: 'float'},
                {name: 'comments', type: 'string'},
                {name: 'latitude', type: 'float'},
                {name: 'longitude', type: 'float'}
            ];

    var reader = new GeoExt.data.FeatureReader({},cols);

    var store = new GeoExt.data.FeatureStore({
        reader: reader,
        fields: cols,
        autoLoad: false
    });
    // create grid panel configured with feature store
    gridPanel = new Ext.grid.GridPanel({
        title: "Results",
        height: 500,
        region:"center",
        store: store,
        columns: [{
            header: "Station",
            width: 100,
            sortable: true,
            dataIndex: "station"
        }, {
            header: "Survey",
            width: 40,
            sortable: true,
            dataIndex: "survey"
        }, {
            header: "Type",
            width: 40,
            sortable: true,
            dataIndex: "type"
        }, {
            header: "Water depth [m]",
            width: 40,
            sortable: true,
            dataIndex: "w_depth_m"
        }, {
            header: "Comments",
            width: 100,
            align: 'right',
            sortable: true,
            dataIndex: "comments"
    }],
        sm: select
    });

    gridPanel.on('rowdblclick', function(g,rowIdx,r){
        rec = store.getAt(rowIdx);
        map.setCenter(
            new OpenLayers.LonLat(
                rec.get('longitude'),
                rec.get('latitude')),
            10);
    });

    searchPanel = new Ext.Panel({
        layout: "border",
        region: "west",
        collapsible: true,
        width: 400,
        items: [formPanel,gridPanel]
    });
    mainPanel = new Ext.Panel({
        height: 600,
        renderTo: "mainpanel",
        layout: "border",
        items: [searchPanel,mappanel,layerTree]
    });

});
[/code]

thanks to Eric Lemoine I understand that the PHP script I'm using for the 
postgis request (update https://gist.github.com/3763701), should allow 
filtering the features I'm looking for (ie.WHERE ... LIKE ...). This script has 
a "parameters" option that should give this but so far it only throws an error.

Sorry for probably this very simple question but I'm just starting using 
GeoJSON and protocol.HTTP, I'd appreciate your support, thanks,

Gery



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