Golang : Executing and evaluating nested loop in html template
Alright, just a minor problem and putting the solution here on how to fix this problem for future reference. Basically, I need to loop two slices inside HTML template and somehow the inner loop will not be evaluated. Attempts to range
over the inner slice will cause this error message:
template: editRenterPageBody:90:36: executing "editRenterPageBody" at <.currentlyRentedTheseProperties>: can't evaluate field currentlyRentedTheseProperties in type models.Property
and the code that caused this error message:
{{range $forRent := .propertiesForRent}} {{ range $rented := .currentlyRentedTheseProperties}} <!-- can't evaluate field error! --> <option value="{{ $forRent.ID }}" {{ if (eq $forRent.ID $rented.ID )}} {{ print "selected" }} {{ end }}>{{ (wordlimiter $forRent.Name 5) }}</option> {{end}} {{end}}
after some investigation, the error message is caused by a missing '$`. We can read from the official documentation:
When execution begins, $ is set to the data argument passed to Execute, that is, to the starting value of dot.
Therefore, to fix this problem, we just add a $
in front of the inner loop.
{{range $forRent := .propertiesForRent}} {{ range $rented := $.currentlyRentedTheseProperties}} <!-- need $. here instead of . --> <option value="{{ $forRent.ID }}" {{ if (eq $forRent.ID $rented.ID )}} {{ print "selected" }} {{ end }}>{{ (wordlimiter $forRent.Name 5) }}</option> {{end}} {{end}}
Hope this helps!
Happy coding!
Reference :
See also : Golang : How to use if, eq and print properly in html template
By Adam Ng
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