topic Re: Filter Array in ArcGIS JavaScript Maps SDK Questions

Filter Array

jaykapalczynski — Wed, 21 Oct 2015 17:40:14 GMT

I have a query that:

is selecting features via a Buffers Geometry
It grabs that array, pushed to a Function and does a Unique filter on that array
It then returns it to a table created via JavaScript.

I am not seeing a fully unique return set....as you can see in the attachment there are two "sunfish, bluespotted" being returned even thought he COMMON_NAME field is the same as specified in the Unique Filter.

I am wondering if this is not working correctly?

do I have something set up wrong?

It is decreasing the number of returned records but does not seem to be getting all of unique values....I checked my data and this field seems to be unique, wondering if I am doing something wrong.

// SNIP.....

var query3 = new Query();

query3.geometry = bufferGeometry;

// Select the Points within the Buffer and show them

featureLayerVAFWIS.selectFeatures(query3, FeatureLayer.SELECTION_NEW, function(results){

});

// Query for the records with the given object IDs and populate the grid

featureLayerVAFWIS.queryFeatures(query3, function (featureSet) {

updateGrid3(featureSet);

});

function updateGrid3(featureSet) {

var data = arrayUtils.map(featureSet.features, function (entry, i) {

return {

id: entry.attributes.OBJECTID,

ObsID: entry.attributes.ObsID,

SppBova: entry.attributes.SppBova,

COMMON_NAME: entry.attributes.COMMON_NAME,

GENUS: entry.attributes.GENUS,

SPECIES: entry.attributes.SPECIES,

Tier: entry.attributes.Tier,

FedStatus: entry.attributes.FedStatus,

TaxaGrp: entry.attributes.TaxaGrp,

};

});

var uniqueName = [];

var UniquValues = array.filter(data, function (item) {

var IsNameUnique = true;

array.forEach(uniqueName, function (value) {

if (value == (item.COMMON_NAME)) {

IsNameUnique = false;

}

});

if (IsNameUnique) {

uniqueName.push(item.COMMON_NAME);

}

return IsNameUnique;

});

var i;

var out = "<table id=t01>";

for(i = 0; i < uniqueName.length; i++) {

out += "<tr><td>" +

arr.id +

"</td><td>" +

arr.ObsID +

"</td><td>" +

arr.SppBova +

"</td><td>" +

arr.COMMON_NAME +

"</td><td>" +

arr.GENUS +

"</td><td>" +

arr.SPECIES +

"</td><td>" +

arr.Tier +

"</td><td>" +

arr.FedStatus +

"</td><td>" +

arr.TaxaGrp +

"</td></tr>";

}

out += "</table>";

document.getElementById("id01").innerHTML = out;

dom.byId('upload-function').innerHTML = "See Results below";

domStyle.set(loadingShapefile, "display", "none");

}

Re: Filter Array

KenBuja — Wed, 21 Oct 2015 17:50:55 GMT

Try filtering your array like this

function filterUnique(values){

var unique = {};

return dojo.filter(values, function(value) {

if (!unique[value]) {

unique[value] = true;

return true;

}

return false;

});

}

Re: Filter Array

jaykapalczynski — Wed, 21 Oct 2015 17:57:57 GMT

Sound I put that function outside the existing function and pass the array "data" to it?

Re: Filter Array

KenBuja — Sun, 12 Dec 2021 03:15:06 GMT

Untested, but I think you could also do this

var UniqueValues = return array.filter(data, function(value) {
        if (!unique[value]) {
            unique[value] = true;
            return true;
        }
        return false;
});

Re: Filter Array

jaykapalczynski — Wed, 21 Oct 2015 18:14:44 GMT

I tried this and get error: "unexpected Token Return"

I changed values to the array name data

var UniqueValues = return dojo.filter(data, function(value) {

if (!unique[value]) {

unique[value] = true;

return true;

}

return false;

});

Re: Filter Array

KenBuja — Wed, 21 Oct 2015 18:21:15 GMT

Sorry, I was updating the code when you copied it out.

Re: Filter Array

jaykapalczynski — Wed, 21 Oct 2015 23:13:57 GMT

If I use your latest example I get this error: Uncaught SyntaxError: Unexpected token return
If I remove the "return" as seen below I get this error: ReferenceError: unique is not defined(…)

Am I missing a reference to something?

My other issue is that I am trying to get the unique records from 1 or 2 fields...not the entire item list.

function updateGrid3(featureSet) {

var data = arrayUtils.map(featureSet.features, function (entry, i) {

return {

id: entry.attributes.OBJECTID,

ObsID: entry.attributes.ObsID,

SppBova: entry.attributes.SppBova,

COMMON_NAME: entry.attributes.COMMON_NAME,

GENUS: entry.attributes.GENUS,

SPECIES: entry.attributes.SPECIES,

Tier: entry.attributes.Tier,

FedStatus: entry.attributes.FedStatus,

TaxaGrp: entry.attributes.TaxaGrp,

};

});

var UniqueValues = array.filter(data, function(value) {

if (!unique[value]) {

unique[value] = true;

return true;

}

return false;

});

Re: Filter Array

jaykapalczynski — Thu, 22 Oct 2015 16:21:35 GMT

Still getting errors from the "return" from your code so I tried it this way but not getting Unique values....

var newarr = [];

var unique = {};

dojo.forEach(data, function(item) {

if (!unique[item.GENUS + item.SPECIES]) {

newarr.push(item);

unique[item.GENUS + item.SPECIES] = item;

}

});

Re: Filter Array

thejuskambi — Thu, 22 Oct 2015 16:38:50 GMT

Hello jay

i wa look at the part where you build the html,and was not able to understand where arr came from. try looking at that variable and see if something is wrong there.

var i;

var out = "<table id=t01>";

for(i = 0; i < uniqueName.length; i++) {

out += "<tr><td>" +

arr.id +

"</td><td>" +

arr.ObsID +

"</td><td>" +

arr.SppBova +

"</td><td>" +

arr.COMMON_NAME +

"</td><td>" +

arr.GENUS +

"</td><td>" +

arr.SPECIES +

"</td><td>" +

arr.Tier +

"</td><td>" +

arr.FedStatus +

"</td><td>" +

arr.TaxaGrp +

"</td></tr>";

}

out += "</table>";

document.getElementById("id01").innerHTML = out;

Re: Filter Array

TracySchloss — Thu, 22 Oct 2015 17:23:06 GMT

I start with an empty array myArr = []. Then as I step through the output of my result handler, I check to see if a value is already in the array like this:

var pos = myArr.lastIndexOf(value);

if (pos == -1) { //value wasn't found

myArr.push(value)

}

Only new values that aren't already in the array are added.

I'm not sure where this fits into your code.

Re: Filter Array

jaykapalczynski — Thu, 22 Oct 2015 20:59:27 GMT

Think I may have it....another colleague pointed something out...have to test and then will post all code.