Points













Lines













Polygons













Vector labels example

Example of GeoJSON features with labels.

Note: The 'Text/Wrap' option is currently not working properly. This is because ol3 uses Canvas's strokeText and fillText functions that do not support text wrapping.

geojson, vector, openstreetmap, label
<!DOCTYPE html>
<html>
<head>
<title>Vector labels example</title>
<script src="https://code.jquery.com/jquery-1.11.2.min.js"></script>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/css/bootstrap.min.css">
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.5/js/bootstrap.min.js"></script>
<link rel="stylesheet" href="http://openlayers.org/en/v3.9.0/css/ol.css" type="text/css">
<script src="http://openlayers.org/en/v3.9.0/build/ol.js"></script>

<style>
h2 {
  font-size: 1.5em;
  line-height: 15px;
}

.scale-cnt {
  margin: 5px;
}

.edit-form-ctn {
}

.edit-form {
  float: left;
  margin: 5px;
  width: 230px;
  padding: 4px;
  border: 1px solid black;
}

.edit-form input[type="button"] {
  float: right;
}

.edit-form-elem label {
  display: block;
  float: left;
  width: 85px;
}

.edit-form-elem input[type="text"] {
  width: 60px;
}

.edit-form-elem select {
  width: 130px;
}

</style>
</head>
<body>
<div class="container-fluid">

<div class="row-fluid">
  <div class="span12">
    <div id="map" class="map"></div>
  </div>
</div>

<div class="edit-form">
  <input id="refresh-points" type="button" value="Refresh" />
  <h2>Points</h2>
  <div class="edit-form-elem">
    <label>Text: </label>
    <select id="points-text">
      <option value="hide">Hide</option>
      <option value="normal">Normal</option>
      <option value="shorten" selected="selected">Shorten</option>
      <option value="wrap">Wrap</option>
    </select>
    <br />
    <label title="Max Resolution Denominator">MaxReso.:</label>
    <select id="points-maxreso">
      <option value="38400">38,400</option>
      <option value="19200">19,200</option>
      <option value="9600">9,600</option>
      <option value="4800">4,800</option>
      <option value="2400">2,400</option>
      <option value="1200" selected="selected">1,200</option>
      <option value="600">600</option>
      <option value="300">300</option>
      <option value="150">150</option>
      <option value="75">75</option>
      <option value="32">32</option>
      <option value="16">16</option>
      <option value="8">8</option>
    </select>
    <br />
    <label>Align: </label>
    <select id="points-align">
      <option value="center" selected="selected">Center</option>
      <option value="end">End</option>
      <option value="left">Left</option>
      <option value="right">Right</option>
      <option value="start">Start</option>
    </select>
    <br />
    <label>Baseline: </label>
    <select id="points-baseline">
      <option value="alphabetic">Alphabetic</option>
      <option value="bottom">Bottom</option>
      <option value="hanging">Hanging</option>
      <option value="ideographic">Ideographic</option>
      <option value="middle" selected="selected">Middle</option>
      <option value="top">Top</option>
    </select>
    <br />
    <label>Rotation: </label>
    <select id="points-rotation">
      <option value="0">0°</option>
      <option value="0.785398164">45°</option>
      <option value="1.570796327">90°</option>
    </select>
    <br />
    <label>Font: </label>
    <select id="points-font">
      <option value="Arial" selected="selected">Arial</option>
      <option value="Courier New">Courier New</option>
      <option value="Quattrocento Sans">Quattrocento</option>
      <option value="Verdana">Verdana</option>
    </select>
    <br />
    <label>Weight: </label>
    <select id="points-weight">
      <option value="bold">Bold</option>
      <option value="normal" selected="selected">Normal</option>
    </select>
    <br />
    <label>Size: </label>
    <input type="text" value="12px" id="points-size" />
    <br />
    <label>Offset X:</label>
    <input type="text" value="0" id="points-offset-x" />
    <br />
    <label>Offset Y:</label>
    <input type="text" value="0" id="points-offset-y" />
    <br />
    <label>Color :</label>
    <input type="text" value="#aa3300" id="points-color" />
    <br />
    <label title="Outline Color">O. Color:</label>
    <input type="text" value="#ffffff" id="points-outline" />
    <br />
    <label title="Outline Width">O. Width :</label>
    <input type="text" value="3" id="points-outline-width" />
  </div>
</div>

<div class="edit-form">
  <input id="refresh-lines" type="button" value="Refresh" />
  <h2>Lines</h2>
  <div class="edit-form-elem">
    <label>Text: </label>
    <select id="lines-text">
      <option value="hide">Hide</option>
      <option value="normal">Normal</option>
      <option value="shorten">Shorten</option>
      <option value="wrap" selected="selected">Wrap</option>
    </select>
    <br />
    <label title="Max Resolution Denominator">MaxReso.:</label>
    <select id="lines-maxreso">
      <option value="38400">38,400</option>
      <option value="19200">19,200</option>
      <option value="9600">9,600</option>
      <option value="4800">4,800</option>
      <option value="2400">2,400</option>
      <option value="1200" selected="selected">1,200</option>
      <option value="600">600</option>
      <option value="300">300</option>
      <option value="150">150</option>
      <option value="75">75</option>
      <option value="32">32</option>
      <option value="16">16</option>
      <option value="8">8</option>
    </select>
    <br />
    <label>Align: </label>
    <select id="lines-align">
      <option value="center" selected="selected">Center</option>
      <option value="end">End</option>
      <option value="left">Left</option>
      <option value="right">Right</option>
      <option value="start">Start</option>
    </select>
    <br />
    <label>Baseline: </label>
    <select id="lines-baseline">
      <option value="alphabetic">Alphabetic</option>
      <option value="bottom">Bottom</option>
      <option value="hanging">Hanging</option>
      <option value="ideographic">Ideographic</option>
      <option value="middle" selected="selected">Middle</option>
      <option value="top">Top</option>
    </select>
    <br />
    <label>Rotation: </label>
    <select id="lines-rotation">
      <option value="0">0°</option>
      <option value="0.785398164">45°</option>
      <option value="1.570796327">90°</option>
    </select>
    <br />
    <label>Font: </label>
    <select id="lines-font">
      <option value="Arial">Arial</option>
      <option value="Courier New" selected="selected">Courier New</option>
      <option value="Quattrocento Sans">Quattrocento</option>
      <option value="Verdana">Verdana</option>
    </select>
    <br />
    <label>Weight: </label>
    <select id="lines-weight">
      <option value="bold" selected="selected">Bold</option>
      <option value="normal">Normal</option>
    </select>
    <br />
    <label>Size: </label>
    <input type="text" value="12px" id="lines-size" />
    <br />
    <label>Offset X:</label>
    <input type="text" value="0" id="lines-offset-x" />
    <br />
    <label>Offset Y:</label>
    <input type="text" value="0" id="lines-offset-y" />
    <br />
    <label>Color :</label>
    <input type="text" value="green" id="lines-color" />
    <br />
    <label title="Outline Color">O. Color:</label>
    <input type="text" value="#ffffff" id="lines-outline" />
    <br />
    <label title="Outline Width">O. Width :</label>
    <input type="text" value="3" id="lines-outline-width" />
  </div>
</div>

<div class="edit-form">
  <input id="refresh-polygons" type="button" value="Refresh" />
  <h2>Polygons</h2>
  <div class="edit-form-elem">
    <label>Text: </label>
    <select id="polygons-text">
      <option value="hide">Hide</option>
      <option value="normal" selected="selected">Normal</option>
      <option value="shorten">Shorten</option>
      <option value="wrap">Wrap</option>
    </select>
    <br />
    <label title="Max Resolution Denominator">MaxReso.:</label>
    <select id="polygons-maxreso">
      <option value="38400">38,400</option>
      <option value="19200">19,200</option>
      <option value="9600">9,600</option>
      <option value="4800">4,800</option>
      <option value="2400">2,400</option>
      <option value="1200" selected="selected">1,200</option>
      <option value="600">600</option>
      <option value="300">300</option>
      <option value="150">150</option>
      <option value="75">75</option>
      <option value="32">32</option>
      <option value="16">16</option>
      <option value="8">8</option>
    </select>
    <br />
    <label>Align: </label>
    <select id="polygons-align">
      <option value="center" selected="selected">Center</option>
      <option value="end">End</option>
      <option value="left">Left</option>
      <option value="right">Right</option>
      <option value="start">Start</option>
    </select>
    <br />
    <label>Baseline: </label>
    <select id="polygons-baseline">
      <option value="alphabetic">Alphabetic</option>
      <option value="bottom">Bottom</option>
      <option value="hanging">Hanging</option>
      <option value="ideographic">Ideographic</option>
      <option value="middle" selected="selected">Middle</option>
      <option value="top">Top</option>
    </select>
    <br />
    <label>Rotation: </label>
    <select id="polygons-rotation">
      <option value="0">0°</option>
      <option value="0.785398164">45°</option>
      <option value="1.570796327">90°</option>
    </select>
    <br />
    <label>Font: </label>
    <select id="polygons-font">
      <option value="Arial">Arial</option>
      <option value="Courier New">Courier New</option>
      <option value="Quattrocento Sans">Quattrocento</option>
      <option value="Verdana" selected="selected">Verdana</option>
    </select>
    <br />
    <label>Weight: </label>
    <select id="polygons-weight">
      <option value="bold" selected="selected">Bold</option>
      <option value="normal">Normal</option>
    </select>
    <br />
    <label>Size: </label>
    <input type="text" value="10px" id="polygons-size" />
    <br />
    <label>Offset X:</label>
    <input type="text" value="0" id="polygons-offset-x" />
    <br />
    <label>Offset Y:</label>
    <input type="text" value="0" id="polygons-offset-y" />
    <br />
    <label>Color :</label>
    <input type="text" value="blue" id="polygons-color" />
    <br />
    <label title="Outline Color">O. Color:</label>
    <input type="text" value="#ffffff" id="polygons-outline" />
    <br />
    <label title="Outline Width">O. Width :</label>
    <input type="text" value="3" id="polygons-outline-width" />
  </div>
</div>

</div>
<script>
var myDom = {
  points: {
    text: document.getElementById('points-text'),
    align: document.getElementById('points-align'),
    baseline: document.getElementById('points-baseline'),
    rotation: document.getElementById('points-rotation'),
    font: document.getElementById('points-font'),
    weight: document.getElementById('points-weight'),
    size: document.getElementById('points-size'),
    offsetX: document.getElementById('points-offset-x'),
    offsetY: document.getElementById('points-offset-y'),
    color: document.getElementById('points-color'),
    outline: document.getElementById('points-outline'),
    outlineWidth: document.getElementById('points-outline-width'),
    maxreso: document.getElementById('points-maxreso')
  },
  lines: {
    text: document.getElementById('lines-text'),
    align: document.getElementById('lines-align'),
    baseline: document.getElementById('lines-baseline'),
    rotation: document.getElementById('lines-rotation'),
    font: document.getElementById('lines-font'),
    weight: document.getElementById('lines-weight'),
    size: document.getElementById('lines-size'),
    offsetX: document.getElementById('lines-offset-x'),
    offsetY: document.getElementById('lines-offset-y'),
    color: document.getElementById('lines-color'),
    outline: document.getElementById('lines-outline'),
    outlineWidth: document.getElementById('lines-outline-width'),
    maxreso: document.getElementById('lines-maxreso')
  },
  polygons: {
    text: document.getElementById('polygons-text'),
    align: document.getElementById('polygons-align'),
    baseline: document.getElementById('polygons-baseline'),
    rotation: document.getElementById('polygons-rotation'),
    font: document.getElementById('polygons-font'),
    weight: document.getElementById('polygons-weight'),
    size: document.getElementById('polygons-size'),
    offsetX: document.getElementById('polygons-offset-x'),
    offsetY: document.getElementById('polygons-offset-y'),
    color: document.getElementById('polygons-color'),
    outline: document.getElementById('polygons-outline'),
    outlineWidth: document.getElementById('polygons-outline-width'),
    maxreso: document.getElementById('polygons-maxreso')
  }
};

var getText = function(feature, resolution, dom) {
  var type = dom.text.value;
  var maxResolution = dom.maxreso.value;
  var text = feature.get('name');

  if (resolution > maxResolution) {
    text = '';
  } else if (type == 'hide') {
    text = '';
  } else if (type == 'shorten') {
    text = text.trunc(12);
  } else if (type == 'wrap') {
    text = stringDivider(text, 16, '\n');
  }

  return text;
};


var createTextStyle = function(feature, resolution, dom) {
  var align = dom.align.value;
  var baseline = dom.baseline.value;
  var size = dom.size.value;
  var offsetX = parseInt(dom.offsetX.value, 10);
  var offsetY = parseInt(dom.offsetY.value, 10);
  var weight = dom.weight.value;
  var rotation = parseFloat(dom.rotation.value);
  var font = weight + ' ' + size + ' ' + dom.font.value;
  var fillColor = dom.color.value;
  var outlineColor = dom.outline.value;
  var outlineWidth = parseInt(dom.outlineWidth.value, 10);

  return new ol.style.Text({
    textAlign: align,
    textBaseline: baseline,
    font: font,
    text: getText(feature, resolution, dom),
    fill: new ol.style.Fill({color: fillColor}),
    stroke: new ol.style.Stroke({color: outlineColor, width: outlineWidth}),
    offsetX: offsetX,
    offsetY: offsetY,
    rotation: rotation
  });
};


// Polygons
var createPolygonStyleFunction = function() {
  return function(feature, resolution) {
    var style = new ol.style.Style({
      stroke: new ol.style.Stroke({
        color: 'blue',
        width: 1
      }),
      fill: new ol.style.Fill({
        color: 'rgba(0, 0, 255, 0.1)'
      }),
      text: createTextStyle(feature, resolution, myDom.polygons)
    });
    return [style];
  };
};

var vectorPolygons = new ol.layer.Vector({
  source: new ol.source.Vector({
    url: 'data/geojson/polygon-samples.geojson',
    format: new ol.format.GeoJSON()
  }),
  style: createPolygonStyleFunction()
});


// Lines
var createLineStyleFunction = function() {
  return function(feature, resolution) {
    var style = new ol.style.Style({
      stroke: new ol.style.Stroke({
        color: 'green',
        width: 2
      }),
      text: createTextStyle(feature, resolution, myDom.lines)
    });
    return [style];
  };
};

var vectorLines = new ol.layer.Vector({
  source: new ol.source.Vector({
    url: 'data/geojson/line-samples.geojson',
    format: new ol.format.GeoJSON()
  }),
  style: createLineStyleFunction()
});


// Points
var createPointStyleFunction = function() {
  return function(feature, resolution) {
    var style = new ol.style.Style({
      image: new ol.style.Circle({
        radius: 10,
        fill: new ol.style.Fill({color: 'rgba(255, 0, 0, 0.1)'}),
        stroke: new ol.style.Stroke({color: 'red', width: 1})
      }),
      text: createTextStyle(feature, resolution, myDom.points)
    });
    return [style];
  };
};

var vectorPoints = new ol.layer.Vector({
  source: new ol.source.Vector({
    url: 'data/geojson/point-samples.geojson',
    format: new ol.format.GeoJSON()
  }),
  style: createPointStyleFunction()
});

var map = new ol.Map({
  layers: [
    new ol.layer.Tile({
      source: new ol.source.MapQuest({layer: 'osm'})
    }),
    vectorPolygons,
    vectorLines,
    vectorPoints
  ],
  target: 'map',
  view: new ol.View({
    center: [-8161939, 6095025],
    zoom: 8
  })
});

$('#refresh-points').click(function() {
  vectorPoints.setStyle(createPointStyleFunction());
});

$('#refresh-lines').click(function() {
  vectorLines.setStyle(createLineStyleFunction());
});

$('#refresh-polygons').click(function() {
  vectorPolygons.setStyle(createPolygonStyleFunction());
});


/**
 * @param {number} n The max number of characters to keep.
 * @return {string} Truncated string.
 */
String.prototype.trunc = String.prototype.trunc ||
    function(n) {
      return this.length > n ? this.substr(0, n - 1) + '...' : this.substr(0);
    };


// http://stackoverflow.com/questions/14484787/wrap-text-in-javascript
function stringDivider(str, width, spaceReplacer) {
  if (str.length > width) {
    var p = width;
    for (; p > 0 && (str[p] != ' ' && str[p] != '-'); p--) {
    }
    if (p > 0) {
      var left;
      if (str.substring(p, p + 1) == '-') {
        left = str.substring(0, p + 1);
      } else {
        left = str.substring(0, p);
      }
      var right = str.substring(p + 1);
      return left + spaceReplacer + stringDivider(right, width, spaceReplacer);
    }
  }
  return str;
}

</script>
</body>
</html>