topic Re: Arcade: Create Filter On Buffer & Intersect of Feature in ArcGIS Online Questions

Arcade: Create Filter On Buffer & Intersect of Feature

ArmstKP — Thu, 05 May 2022 16:51:35 GMT

I have a bench layer for example. Two of the fields are {Park_Name} and {condition_score}

I am trying to write an expression that shows me the average bench score in the park, where I clicked on that bench.

I at least have this built so far:

var benchBuff = Buffer($feature, 3000, 'foot')

var benchWithin = Intersects(benchBuff, $layer)

return Round(Average(benchWithin, "condition_score"), 1)

I am just not sure how or where to include the {Park_Name} filter and/or sql variable in the expression?

Re: Arcade: Create Filter On Buffer & Intersect of Feature

jcarlson — Thu, 05 May 2022 17:31:14 GMT

You just need the output limited to benches in the same park? You can filter the layer earlier in the expression by attribute, and then use those filtered features in your Intersects function

var park_benches = Filter($layer, `Park_Name = '${$feature['Park_Name']}'`) var benchBuff = Buffer($feature, 3000, 'foot') var benchWithin = Intersects(benchBuff, park_benches) return Round(Average(benchWithin, "condition_score"), 1)

Re: Arcade: Create Filter On Buffer & Intersect of Feature

ArmstKP — Thu, 05 May 2022 18:02:57 GMT

Thank you very much Josh!

I have a question about two of the characters I have pictured below. What are these?

Re: Arcade: Create Filter On Buffer & Intersect of Feature

jcarlson — Thu, 05 May 2022 18:13:42 GMT

Ah, those are called backticks. You use them in Arcade (and other programming languages) to create template literals.

Suppose you had two variables you wanted to pipe into some text. You could just concatenate the text like this:

var x = 'something'
var y = 'something else'

'Variable x is ' + x + ', and variable y is ' + y + '.'

returns:

'Variable x is something, and variable y is something else.'

But a template literal inserts the variables directly into the string.

`Variable x is ${x}, and variable y is ${y}.`

Both work, but I personally prefer the backtick style, as I find it easier to use and visualize the resulting string.

Re: Arcade: Create Filter On Buffer & Intersect of Feature

ArmstKP — Thu, 05 May 2022 18:24:19 GMT

Thanks for that info, didn't know!

Re: Arcade: Create Filter On Buffer & Intersect of Feature

KimberlyGarbade — Tue, 17 Jan 2023 20:58:58 GMT

I know this post isn't "fresh", but I wanted to thank you for that first line of code in the solution. Fantastic! I knew I had used an attribute of $feature in a filter before, but I couldn't remember the syntax and finding it online is close to impossible...maybe I'm Google search challenged. Finally, I tripped over it here (probably where I stole it from the first time I did it). Man, could Esri have come up with a more convoluted syntax?... Tildes, single quotes, 2 dollar signs, and every kind of bracket....Yikes. Thank you for figuring this out for all of us.