How to compare the length of a list in html/template in golang?

html go equals go-html-template
Dany picture Dany · Mar 13, 2016 · Viewed 32.5k times · Source

I am trying to compare the length of a list in golang html/template. But it is loading forever in html.

{{ $length := len .SearchData }} {{ if eq $length "0" }}
    Sorry. No matching results found
{{ end }}

Could anyone help me with this?

Answer

Aruna Herath picture Aruna Herath · Mar 13, 2016

From documentation,

{{if pipeline}} T1 {{end}}: If the value of the pipeline is empty, no output is generated; otherwise, T1 is executed. The empty values are false, 0, any nil pointer or interface value, and any array, slice, map, or string of length zero. Dot is unaffected.

So if you want to check if the .SearchData slice/array/map is empty just use,

{{if not .SearchData}} Nothing to show {{end}}

Even your code runs fine if string "0" is replaced by int 0

{{ $length := len .SearchData }} {{ if eq $length 0 }}
    Sorry. No matching results found
{{ end }}

http://play.golang.org/p/Q44qyRbKRB

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