deactivate.doBuffer

simonmiles · ‎02-17-2011

Hi,

I'm going back to basics and working with a sample. What i'm trying to do and failing is in the first instance is to deactivate the doBuffer function and only activate it when i clicking on a button.

I'm using this esri sample
http://resources.esri.com/help/9.3/arcgisserver/apis/javascript/arcgis/help/jssamples_start.htm#jssa...

what i've tried and failed with is removing "dojo.connect(map, "onClick", doBuffer);" from the function initialize...

gsvc = new esri.tasks.GeometryService("http://sampleserver1.arcgisonline.com/arcgis/rest/services/Geometry/GeometryServer");
      dojo.connect(map, "onClick", doBuffer);

adding in doBuffer.deactivate (); in the below funcation....

function doBuffer(evt) {
      doBuffer.deactivate ();
      map.graphics.clear();
      var symbol = new esri.symbol.SimpleMarkerSymbol();
      var graphic = new esri.Graphic(evt.mapPoint, symbol);

then in the body adding in a button....

<button type="button" onClick="doBuffer.activate();">Click Me!</button>

But its just not happening, where am i going wrong?

Any help would be great

Regards

Simon

MarioObendorfer · ‎02-17-2011

Hi,

I'm a little bit confused about your code but I'll try to explain what you should do when you try to de/activate some functionality with buttonclick ...

Connect your button button with onclick handler for the map ... e.g.:

<button onclick="javascript: eventhandle = dojo.connect(map, ev, fun)">

fun = function(event) {
//place business logic here => e.g. doBuffercode
dojo.disconnect(eventhandle); //disconnect this evenhandler => only one buffering is done ... you can place this line of code on antoher button or wherever you want to trigger the deactivation
}

The code you wrote doBuffer.deactivate() should do nothing because doBuffer is a function itselfe and not a object you can call a function on. In the esri example the activate() and deactivate() functions are called on the drawtoolbar object. I think you mixed those things up.

Hope that helps .. if not post more of your code.

Greets Tol

HemingZhu · ‎02-17-2011

Hi,

I'm going back to basics and working with a sample. What i'm trying to do and failing is in the first instance is to deactivate the doBuffer function and only activate it when i clicking on a button.

I'm using this esri sample
http://resources.esri.com/help/9.3/arcgisserver/apis/javascript/arcgis/help/jssamples_start.htm#jssa...

what i've tried and failed with is removing "dojo.connect(map, "onClick", doBuffer);" from the function initialize...

gsvc = new esri.tasks.GeometryService("http://sampleserver1.arcgisonline.com/arcgis/rest/services/Geometry/GeometryServer");
      dojo.connect(map, "onClick", doBuffer);

adding in doBuffer.deactivate (); in the below funcation....

function doBuffer(evt) {
      doBuffer.deactivate ();
      map.graphics.clear();
      var symbol = new esri.symbol.SimpleMarkerSymbol();
      var graphic = new esri.Graphic(evt.mapPoint, symbol);

then in the body adding in a button....

<button type="button" onClick="doBuffer.activate();">Click Me!</button>

But its just not happening, where am i going wrong?

Any help would be great

Regards

Simon

Try this: put onclickConnect = dojo.connect(map, "onClick", doBuffer); in your button's onClick handler to activate the map click event. Then put this: dojo.disconnect(onclickConnect); in your doBuffer method to deactivate or dissconnect map click event. Note: set onclickConnect as a global variable.

simonmiles · ‎02-17-2011

hi hzhu,

thanks for your help and i've added in yoor code but there is still something up with my code.

<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01//EN" "http://www.w3.org/TR/html4/strict.dtd">
<html>
<head>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
<meta http-equiv="X-UA-Compatible" content="IE=7" />
<title>Buffer</title>
<link rel="stylesheet" type="text/css" href="http://serverapi.arcgisonline.com/jsapi/arcgis/1.6/js/dojo/dijit/themes/tundra/tundra.css">
<script src="http://serverapi.arcgisonline.com/jsapi/arcgis/?v=1.6" type="text/javascript"></script>

<script type="text/javascript">
dojo.require("esri.map");
dojo.require("esri.tasks.geometry");

var map = null;
var geometryService = null;
var globals;

function initialize() {
map = new esri.Map("map");
var layer = new esri.layers.ArcGISTiledMapServiceLayer("http://server.arcgisonline.com/ArcGIS/rest/services/ESRI_StreetMap_World_2D/MapServer");
map.addLayer(layer);
map.setExtent(new esri.geometry.Extent(-97.76, 32.32, -96.11, 33.42, new esri.SpatialReference({wkid: 4326})));

geometryService = new esri.tasks.GeometryService("http://sampleserver1.arcgisonline.com/arcgis/rest/services/Geometry/GeometryServer");

}

function doBuffer(evt) {
var globals = dojo.disconnect(map, "onClick", doBuffer);
map.graphics.clear();
var symbol = new esri.symbol.SimpleMarkerSymbol();
var graphic = new esri.Graphic(evt.mapPoint, symbol);

var params = new esri.tasks.BufferParameters();
params.features = [ graphic ];

// CASE [1]: if you want to buffer in angular units.
//params.distances = [ 5, 10 ];
//params.unit = esri.tasks.BufferParameters.UNIT_DEGREE;

// CASE [2]: if you want to buffer in linear units such as meters, km, miles etc.
params.distances = [ 2500 ];
params.unit = esri.tasks.BufferParameters.METERS;
params.bufferSpatialReference = new esri.SpatialReference({wkid: 32662});
params.outSpatialReference = map.spatialReference;

geometryService.buffer(params, showBuffer);
}

function showBuffer(features) {

var symbol = new esri.symbol.SimpleFillSymbol(
esri.symbol.SimpleFillSymbol.STYLE_SOLID,
new esri.symbol.SimpleLineSymbol(
esri.symbol.SimpleLineSymbol.STYLE_SOLID,
new dojo.Color([0,0,255,0.65]), 2
),
new dojo.Color([0,0,255,0.35])
);

for (var j=0, jl=features.length; j<jl; j++) {
features.setSymbol(symbol);
map.graphics.add(features);
}
}

dojo.addOnLoad(initialize);
</script>

</head>

<body class="tundra">
<b>Click a location on the map to buffer. Click again on another location to buffer again.</b>
<br/>

<button type="button" onClickConnect = dojo.connect(map, "onClick", doBuffer);>Click Me!</button>
<div id="map" style="width:600px; height:400px; border:1px solid #000;"></div>
</body>

</html>

MarioObendorfer · ‎02-18-2011

Hi,

    function doBuffer(evt) {
      var globals = dojo.disconnect(map, "onClick", doBuffer);
      ...
    }

    <button type="button" onClickConnect = dojo.connect(map, "onClick", doBuffer);>Click
[/SIZE]

Change this 2 lines in your code to ....

<input type="button" onclick="globals = dojo.connect(map, 'onClick', doBuffer); " value="Click Me!">

and

function doBuffer(evt) {
      dojo.disconnect(globals);
      ...
    }

A little bit explained .... you need the global var globals for saving a handle to your eventhandler. Assign (=> globals = dojo.connect(etc)) the eventhandler when you click on the button and disconnect the handle when the doBuffer method is calls (=> dojo.disconnect(globals)).

Hope this will help this time ....

Further you should really start reading some JavaScript related artikels about scope and about dojo eventhandling or simply the dojo API.

Greets Tol

simonmiles · ‎02-18-2011

Tol,

Thank you very much for this.

Si