Blanks in a Label

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8
06-01-2018 09:02 AM
KennethRichards
New Contributor III

What is a good way to skip a blank field when creating label expressions? I have a bunch of points that I need labeled with data from multiple fields but some contain blanks. I am working in ArcPro if that makes any difference.

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8 Replies
DanPatterson_Retired
MVP Emeritus

what labelling method are you using? standard or maplex? What types of the fields are involved? labelling language?

Perhaps some examples from your case.

In essence, you can create a labelling function that will use the inputs from fields and translate any nulls to an empty string prior to concatenation

http://pro.arcgis.com/en/pro-app/help/mapping/text/specify-text-for-labels.htm

XanderBakker
Esri Esteemed Contributor

Can you share an example of a label including blank fields and what you want to have as a result? There are multiple ways to achieve this and an example will make it easier to suggest a good way to do this.

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KennethRichards
New Contributor III

Attribute TableAttribute Table 2

I am using Maplex. The fields are text fields.

Map

The Popup2 field has blanks in that I want to omit when I generate the labels. The red arrows are the blanks I am trying to remove.

Right now I am using a basic expression to create them.

[Name2] +  '\n'  +  [PopUp2] +  '\n'  + [DMSLat] +  '\n'  + [DMSLong]

Thanks for taking the time to help.

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DanPatterson_Retired
MVP Emeritus

A demo... a, b, c, d represent field names

they need to be replace with !YourFieldName! in ! marks

Python parser

could be used in a field calculation and I presume in some labeling thing (don't do much mapping with labels, so I will defer to those that do)

a, b, c, d = ['a', '', 'c', 'd']

def prn(a, b, c, d):
    """demo replace the letters with !YourFieldName!
    """
    if b not in ("", " ", None):
        frmt = "{}\n{}\n{}\n{}".format(a, b, c, d)
    else:
        frmt = "{}\n{}\n{}".format(a, c, d)
    return frmt



prn(a, b, c, d)

'a\nc\nd'

print(prn(a, b, c, d))

a
c
d
XanderBakker
Esri Esteemed Contributor

... and since you can use Arcade too for the labeling, find an example below:

var Name2 = "FR-20";
var PopUp2 = null;
var DMSLat = "37°32'5.460\"N";
var DMSLong = "113°4'53.641\"W";

// var Name2 = $feature.Name2;
// var PopUp2 = $feature.PopUp2;
// var DMSLat = $feature.DMSLat;
// var DMSLong = $feature.DMSLong;

var array = [Name2, PopUp2, DMSLat, DMSLong];

var result = "";
for (var i = 0; i < Count(array); i++ ){
    if (IsEmpty(array[i]) == false) {
        if (result == "") {
            result = array[i];
        } else {
            result = result + "\n" + array[i];
        }
    }
}

return result;

On lines 1 to 4 I'm setting some values hard coded. Lines 6 to 9 show how these values can be read from the fields.

This will yield the label without the empty line:

KennethRichards
New Contributor III

I will try this one. I have been wanting to learn Arcade a little more.

XanderBakker
Esri Esteemed Contributor
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DanPatterson_Retired
MVP Emeritus

forgot this missive....

*args would require some field names of indeterminate length

ie prn(!A!, !b!, !cc!, !d!) as the expression

a, b, c, d = ['a', '', 'c', 'd']

def prn(*args):
    """demo replace the letters with !YourFieldName!
    """
    vals = [i for i in args if i not in ("", " ", None)]
    frmt = ("{}\n"*len(vals)).format(*vals)
    return frmt



print(prn(a, b, c, d))  # in the order given
a
c
d


print(prn(a))  # a singleton
a


print(prn(a, d, c, b))  # switch them up
a
d
c

‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

But if you want to change the separator, you can use this variant

# --- requires python 3.6 or above

def prn(*args, sep="..."):
    """demo replace the letters with !YourFieldName!
    """
    vals = [f"{i}"+sep for i in args if i not in ("", " ", None)]
    frmt = ("{}"*len(vals)).format(*vals)
    return frmt



prn(a, c, d)
'a...c...d...'

# ---- change sep="\n" for newline instead