Mask First 5 Characters of SSN when using angular-ui-mask

Question

Im using angular-ui-mask to display ssn in this format 123-45-6789, but i also want to hide the first 5 characters when input box loses focus and show all digits when input box gains focus.

My HTML

<input class="btnDropdown" 
       id="phoneTextInput" 
       ui-mask="{{uimaskpattern}}" 
       ui-mask-placeholder-char=""
       ng-focus="applymask()"
       ng-blur="phoneForm['Phone_'+$index].$viewValue = removemask(contact.contactDetails.attributeDetails.contact)"
       md-minlength="10" 
       md-maxlength="10" 
       name="Phone_{{$index}}" 
       ng-model="contact.contactDetails.attributeDetails.contact">

Angular Code:

Initial Value of uimaskpattern = "999-99-9999"

//When input gets focus
public applymask() {
    this.uimaskpattern = "999-999-9999";
}

//When input loses focus
public removemask(ssn) {
    if (ssn) {
        console.log(ssn);
        this.uimaskpattern = "XXX-XXX-9999";
        let formstring = 'XXX-XXX-'+ssn.slice(6, ssn.length);
        console.log(formstring);
        return formstring;
    }
}

The issue i'm facing is that on blur, If user enters 123456789, then on blur the text becomes XXX-XX-1234, instead of XXX-XX-6789, ie instead of 6789, the appended digits are the first 4, If I just print the returned string with {{}}, it is getting displayed properly

Answer 1

change ng-blur as below

ng-blur="removemask(contact.contactDetails.attributeDetails.contact)"

and remove mask function as follows and check now.It might work

public removemask(ssn) {
    if (ssn) {
        console.log(ssn);
        this.uimaskpattern = "XXX-XXX-9999";
        let formstring = 'XXX-XXX-'+ssn.slice(6, ssn.length);
        console.log(formstring);
        ssn=formstring;
    }
}