use function to add select in options in Hamlet

[kees Bleijenberg]

This is what I do for generating options in a select in Hamlet:

-- as is [0,1,2,3] :: [Int]
-- isOne is a function from Int -> Bool
<select>
   $forall a <- as
      $if isOne a
         <option value=#{show a} selected> #{show a}  (1)
      $else
         <option value=#{show a}> #{show a}           (2)    
This works. I get a select with 1 selected.

When I create a option almost always line 1 is equal to line 2, but the first line contains the word "selected"

Idea: I write the function
selected :: Bool -> Text
selected True = "selected"
selected False = ""

and change the code to
<select>
   $forall a <- as
      <option value=#{show a} #{selected $ isOne a}> #{show a}
         
Unfortunately, now the generated Html is:
<select><option value="0" id="{selected" $ isOne a}> 0</option>
<option value="1" id="{selected" $ isOne a}> 1</option> ....
Not what I want.

What is going wrong en how can I do this better?

Kees

[jsch...@gmail.com]

There is a special syntax in Hamlet for this:

https://www.yesodweb.com/book/shakespearean-templates#shakespearean-templates_attributes

<option value=#{show a} :isOne a:selected> #{show a}

There are also some types of selectField which returns a Field which has a FieldViewFunc which returns a widget that you can embed in your hamlet. Not sure if it's easy to use but the code for <select> is already there.

[kees Bleijenberg]

Thank you.This solves the problem.