<UND></UND> Tags work inconsistently in Arcade

[RandyMcGregor_BMcD]

I am trying to underline the first line in a three line label.

ownlab1 = $feature.ParcelID

ownlab1 = '<UND>'+Text(ownlab1)+'</UND>'

The resulting labels sometimes work and sometimes don't.

I get '3232' for example, which is what I want, but also, '<UND>3234</UND>' I can't figure out what is different about lines that honor the underline tag and those which reject it.

Is there any logical reason for this?

Thank you,

Randy McGregor

[KenBuja · Accepted solution]

If the text contains a "<" or "&", these special characters break formatting tags. You have to replace them with "&lt;" and "&amp;". This line replaces both (and uses template literals)

`<UND>${Replace(Replace($feature.ParcelID, "&", "&amp;"), "<", "&lt;")}</UND>`

[RandyMcGregor_BMcD]

Thanks Ken,

There are no visible troublemaker characters but there may be something 'wrong' with the  values that are ignoring the <UND></UND> tags.

[KenBuja]

What else is in your multi-line string? Do the other elements have the special characters?

[Robert_LeClair]

@RandyMcGregor_BMcD - I tested this with some of my data and noticed a few formatting issues with your label expression.  Instead of a two line arcade expression, how about this - 

"<UND>"+$feature.ParcelID+"</UND>"

It works in my ArcGIS Pro 3.6.x

[RandyMcGregor_BMcD]

No effect, but I appreciate the suggestion. What's weird is that it works on most labels but not others. My guess is that there are some weird characters are in the mix (but they are not clearly visible.). Maybe a unicode vs straight text deal or something nightmarish like that 😕 Thank you.

[Robert_LeClair]

That is odd certainly.  Is the ParcelID field a text field or a numeric field? I wonder if you could create a new field say "opposite" of ParcelID and then use the Field Calculator to populate the field?  By "opposite" I mean, if it's a numeric field, then create a new text field to do the field calculation upon, then apply the UND arcade to the new field for testing purposes.

[RandyMcGregor_BMcD]

Thanks Ken and Robert, I'll give it a try!

[RandyMcGregor_BMcD]

Oookay, so I decided to enter text and it's still being naughty:

var ownlab1 = "<UND>"+"Hi Mom"+"_</UND>"

[KenBuja · Accepted solution]

What else is in the label? If anything in the label contains those special characters, then the formatting tags will break. For example, this code

var ownlab1 = $feature.Site;
var other = "This & that";
"<UND>" + Text(ownlab1) + "</UND>\n" + other;

results in this label

This code fixes it

var ownlab1 = $feature.Site;
var other = Replace("This & that", "&", "&");
'<UND>'+Text(ownlab1)+'</UND>\n' + other;