how to enable or disable editing of a field value depending on another field's value?

I have two fields, one which need to be dependent on the other field's value. The 1st field is "RELEASE" which has "latest" and "on-going" as the dropdown options. The 2nd field is "BUILD" which should be editable only when we select "on-going" as the release. When the release is "latest" it should take a default value and not be editable.

test.html

{{> afQuickField name='Release' options='allowed'  }}
<span title = "eg:PRODUCT/10.X.X.1234 or PRODUCT:latest">
  <a style="font-size:1.2em"><h5>ProductBuild</h5></a>
</span>
{{> afQuickField name='PRODUCT_BUILD' }}

I'm also trying to set the tool tip for PRODUCT_BUILD field so that when a user hover over it, he/she will know the correct format like "PRODUCT:latest" for Latest and "PRODUCT/10.X.X.1234" for "On-going".

schema.js

Release:{
  type: String,
  label: "Release",
  optional: true,
  allowedValues:["LR-Latest Release","OR-Ongoing Release"],
  autoform:{
    afFieldInput:{
      firstOption:"(Select the Release)"
    }
  }
},
PRODUCT_BUILD:{
  type:String,
  label:' ', 
  regEx: /^(PRODUCT)(\/|:)((([0-9]+\.)+[0-9]+)|(latest))/,
  defaultValue:"PRODUCT:latest"
},

How can I do this?

Solution

One of two ways of doing this:

One: Use readonly property within the autoform.

Release:{
  type: String,
  label: "Release",
  optional: true,
  allowedValues:["LR-Latest Release","OR-Ongoing Release"],
  autoform:{
    afFieldInput:{
      firstOption:"(Select the Release)"
    }
  }
},
PRODUCT_BUILD:{
  type:String,
  label:' ', 
  regEx: /^(PRODUCT)(\/|:)((([0-9]+\.)+[0-9]+)|(latest))/,
  defaultValue:"PRODUCT:latest",
  autoform:{
    readonly: function(){
      if(AutoForm.getFieldValue('Release') == 'on-going'){
        // if the above does not get you the "Release" field's value then try:
        // AutoForm.getFieldValue('Release','formID');
        // if your formID is dynamically set, then use AutoForm.getFormId(); to get the form's ID
        return false;
      }
      else {
        return true;
      }
    }
  }
},

Two: Use a custom function to set/unset readonly property

Release:{
  type: String,
  label: "Release",
  optional: true,
  allowedValues:["LR-Latest Release","OR-Ongoing Release"],
  autoform:{
    afFieldInput:{
      firstOption:"(Select the Release)"
    }
  },
  custom: function(){
    if(this.value == 'on-going'){
      $('[name=PRODUCT_BUILD]').prop('readonly', true);
    }
    else {
      $('[name=PRODUCT_BUILD]').prop('readonly', false);
    }
  }
},
PRODUCT_BUILD:{
  type:String,
  label:' ', 
  regEx: /^(PRODUCT)(\/|:)((([0-9]+\.)+[0-9]+)|(latest))/,
  defaultValue:"PRODUCT:latest",
},

You can play around with both methods here before you actually try implementing it.