topic Re: How do I get the first array item and then first array item value from my array? in ArcGIS JavaScript Maps SDK Questions

How do I get the first array item and then first array item value from my array?

ChrisSergent — Sat, 11 Dec 2021 06:44:21 GMT

Here is a code sample that I have that acquires an array of values:

JS Bin - Collaborative JavaScript Debugging

There are signs that display the following. I need to get the objectID from the first sign, and then the installed value and then signId and so on. Then I would go to the next item in the array on button click. How would I do that?

OBJECTID: 9263

INSTALLED: null

SIGNID: 1169

FACING: S

VISIBILITY: Good

CONDITION_: Good

SUPPORTID: 691

TEXT:

COLOR1:

DELINEATOR: None

ILLUM: None

OFFSET: null

MOUNTHT: null

BACKING: Aluminum

WIDTH: null

HEIGHT: null

TXTSIZE: null

NUMSIZE: null

COMMENTS:

TWOSIDED: Y

ATTACHTYPE: Bolts

ATTACHNUM: null

ATTACHLOC: Main pole

SITEOBS: Clear

SIGNSHAPE:

COLOR2:

MUTCD: R1-1 (Stop Sign)

GLOBALID: {34E39E75-F785-4272-8F2E-7A13349817F0}

OBJECTID: 9264

INSTALLED: null

SIGNID: 1168

FACING: E

VISIBILITY: Good

CONDITION_: Good

SUPPORTID: 691

TEXT:

COLOR1:

DELINEATOR: None

ILLUM: None

OFFSET: null

MOUNTHT: null

BACKING: Aluminum

WIDTH: null

HEIGHT: null

TXTSIZE: null

NUMSIZE: null

COMMENTS:

TWOSIDED: Y

ATTACHTYPE: Other

ATTACHNUM: null

ATTACHLOC: Main pole

SITEOBS: Clear

SIGNSHAPE:

COLOR2:

MUTCD: D3-1 (Street sign) - Street Name & Parking Signs

GLOBALID: {C8253B28-2EEA-43B2-BFB0-2F1658741E45}

OBJECTID: 9265

INSTALLED: null

SIGNID: 1167

FACING: N

VISIBILITY: Good

CONDITION_: Good

SUPPORTID: 691

TEXT:

COLOR1:

DELINEATOR: None

ILLUM: None

OFFSET: null

MOUNTHT: null

BACKING: Aluminum

WIDTH: null

HEIGHT: null

TXTSIZE: null

NUMSIZE: null

COMMENTS:

TWOSIDED: Y

ATTACHTYPE: Other

ATTACHNUM: null

ATTACHLOC: Main pole

SITEOBS: Clear

SIGNSHAPE:

COLOR2:

MUTCD: D3-1 (Street sign) - Street Name & Parking Signs

GLOBALID: {75AE4A49-7A0E-48B0-A6DD-4FB318BFFC27}

OBJECTID: 22205

INSTALLED: null

SIGNID: 1169

FACING: S

VISIBILITY: Good

CONDITION_: Good

SUPPORTID: 691

TEXT:

COLOR1:

DELINEATOR: None

ILLUM: None

OFFSET: null

MOUNTHT: null

BACKING: Aluminum

WIDTH: null

HEIGHT: null

TXTSIZE: null

NUMSIZE: null

COMMENTS:

TWOSIDED: Y

ATTACHTYPE: Bolts

ATTACHNUM: null

ATTACHLOC: Main pole

SITEOBS: Clear

SIGNSHAPE:

COLOR2:

MUTCD: R1-1 (Stop Sign)

GLOBALID: {D0188C14-D518-42BE-B36E-CCEDB4474BD3}

I have managed to get the first letter of an attribute to increment however:

 on(dom.byId("btnSupportNext"),"click",function(){
            console.log("Next Works");
            var query = new esriQuery();
            var queryTask = new QueryTask(config.signLayerUrl);
            query.returnGeometry = false;
            query.outFields = ["*"];


            


            query.where = "SUPPORTID = " + dom.byId("supportId").value;
            queryTask.execute(query, function (results) {
                // Attempting to know how many signs are in my results
                // Use gettArray.html to get array values
                console.log("Results start now!");
                console.log(results);


                var resultItems = [];
                var resultCount = results.features.length;
                for (var i = 0; i < resultCount; i++) {
                    var featureAttributes = results.features.attributes.ATTACHLOC;
                    for (var attr in featureAttributes) {
                        console.log("Attribute: " + featureAttributes[attr]);
                    }


                }


               
            })


        });

Re: How do I get the first array item and then first array item value from my array?

RobertScheitlin__GISP — Tue, 23 Jun 2015 00:12:25 GMT

Chris,

I am struggling to see your issue here. When you execute the query you are returned and array and you can get a record from the array just by using the records index in the array. So if you want the first record you would use the array object like this.

var theRecord = results.features[0];

var theRecordAtts = theRecord.attributes;

for the second record you would just increment 0 by 1

theRecord = results.features[1];

Sorry if this is oversimplified and I am just missing your question.

Re: How do I get the first array item and then first array item value from my array?

thejuskambi — Tue, 23 Jun 2015 13:05:49 GMT

your code says featureAttributes but you are assigning a value of the feature

var featureAttributes = results.features.attributes.ATTACHLOC;

it should be

var featureAttributes = results.features.attributes;

Re: How do I get the first array item and then first array item value from my array?

ChrisSergent — Tue, 23 Jun 2015 16:55:23 GMT

Simple is good, but I am trying to get the following. I have an array of two as seen below. For each item in the array, I need to fill in a form, so I only want one item in the array but I need the features.itemInArray.attributes and then the value of ATTACHLOC, ATTACHNUM, ATTACHTYPE and so on for the first button click. The value for ATTACHLOC in the following picture would be Main Pole.

And then I would click on the button again and then I want to populate the values from the second item in the array, but for each attributes item value.

Does this help?

Re: How do I get the first array item and then first array item value from my array?

ChrisSergent — Tue, 23 Jun 2015 17:00:06 GMT

That actually gives me all of the attributes and I need one a at a time.

Re: How do I get the first array item and then first array item value from my array?

DarrenWiens2 — Sat, 11 Dec 2021 06:44:24 GMT

As Robert mostly says, you would use:

results.features.attributes.ATTACHLOC

where i indicates which object to return. Using a global variable, you can track whether i should be 0 or 1.

edit: to get each attribute value, one at a time:

var featureAttributes = results.features.attributes;
for (var key in featureAttributes) {
      console.log(featureAttributes[key]);
}

Re: How do I get the first array item and then first array item value from my array?

KenBuja — Sat, 11 Dec 2021 06:44:26 GMT

But you're needlessly trying to loop through that one attribute with the next lines of your code.

var featureAttributes = results.features.attributes.ATTACHLOC;  
for (var attr in featureAttributes) {  
    console.log("Attribute: " + featureAttributes[attr]);  
}

Re: How do I get the first array item and then first array item value from my array?

ChrisSergent — Tue, 23 Jun 2015 20:00:52 GMT

I know. I want it to increment by one with each click. I believe I may need to set my values before the click event as there appears to be nothing from stopping the loop. It just appears to run completely with each click.

Re: How do I get the first array item and then first array item value from my array?

DarrenWiens2 — Tue, 23 Jun 2015 20:06:36 GMT

By setting a global variable, you can keep track of which click you're on:

var count = 0;

Increment each time the button is clicked (in your execute function):

count++;

Get the proper result (in showResults function):

var featureAttributes = results.features[count].attributes;

Finally, reset the counter when the id changes:

count = 0;

JS Bin - Collaborative JavaScript Debugging

Re: How do I get the first array item and then first array item value from my array?

thejuskambi — Tue, 23 Jun 2015 21:16:13 GMT

Adding to what Darren has mentioned. If you can hold the query result also a part of Global variable, so that you dont have to make a request to server every time. Query once when you open the dialog/form and clear it when you close the dialog/form.

Re: How do I get the first array item and then first array item value from my array?

ChrisSergent — Sat, 11 Dec 2021 06:44:29 GMT

That worked well. Here is my final code for anyone that may have a similar question for both previous and next buttons:

// Cycle through sign information with the previous button
        on(dom.byId("btnSupportPrevious"),"click",function(){
            console.log("Previous Works");
            var query = new esriQuery();
            var queryTask = new QueryTask(config.signLayerUrl);
            query.returnGeometry = false;
            query.outFields = ["*"];






            query.where = "SUPPORTID = " + dom.byId("supportId").value;
            queryTask.execute(query, function (results) {
                ii--;
                // Attempting to know how many signs are in my results
                // Use gettArray.html to get array values




                var resultItems = [];
                var resultCount = results.features.length;
                if (ii > -1) {
                    console.log("Results start now!");
                    console.log(results);
                    var featureAttributes = results.features[ii].attributes.GLOBALID;
                    for (var attr in featureAttributes) {
                        console.log("Attribute: " + featureAttributes);
                    }


                } else {
                    console.log("This is where you will get the support information");
                    //document.getElementById("btnSupportNext").disabled = true;
                }




            })
        });






        var ii;
       
        // Cycle through sign information with the next button
        on(dom.byId("btnSupportNext"),"click",function(){
            console.log("Next Works");
            var query = new esriQuery();
            var queryTask = new QueryTask(config.signLayerUrl);
            query.returnGeometry = false;
            query.outFields = ["*"];


           


            query.where = "SUPPORTID = " + dom.byId("supportId").value;
            queryTask.execute(query, function (results) {
                ii++;
                // Attempting to know how many signs are in my results
                // Use gettArray.html to get array values
               


                var resultItems = [];
                var resultCount = results.features.length;
                if (ii < resultCount) {
                    console.log("Results start now!");
                    console.log(results);
                    var featureAttributes = results.features[ii].attributes.GLOBALID;
                    for (var attr in featureAttributes) {
                        console.log("Attribute: " + featureAttributes);
                    }


                } else {
                    console.log("This is where you will get the support information");
                    //document.getElementById("btnSupportNext").disabled = true;
                }
               
             
            })


        });


        on(dom.byId("btnSignPrevious"),"click",function(){
            console.log("Previous Works");
        });


        on(dom.byId("btnSignNext"), "click", function () {
            console.log("Next Works");
        });

And I updated my application on Github: csergent45/streetSigns at aad189ff1daba057c241f38038f172d045c5bf63 · GitHub

Re: How do I get the first array item and then first array item value from my array?

ChrisSergent — Tue, 23 Jun 2015 21:35:30 GMT

Good call. I added the variable reset on form opening.