How to declare a variable only one time in JavaScript helpers?

Question

I am developing web components with meteor-blaze.

In Template helpers,

Template.Button.helpers({
btnName: function() {
    var FirstBtn = new ButtonComponents('Name', this.class, '50px', '30px', '#DDDDDD');
    return FirstBtn.buttonName();
},
btnClass: function() {
    var FirstBtn = new ButtonComponents('Name', this.class, '50px', '30px', '#DDDDDD');
    return FirstBtn.buttonClass();
},
btnStyle: function() {
    var FirstBtn = new ButtonComponents('Name', this.class, '50px', '30px', '#DDDDDD');
    return FirstBtn.buttonStyle();
}});

I want to declare FirstBtn only one time in helpers.

I don't want to declare FirstBtn outside of helpers because of this.class.

How can I do this?

Answer 1

var FirstBtn;
function getFirstBtn(cls) {
    if (FirstBtn == null) {
        FirstBtn = new ButtonComponents('Name', cls, '50px', '30px', '#DDDDDD');
    }
    return FirstBtn;
}

Template.Button.helpers({
    btnName: function() {
        return getFirstBtn(this.class).buttonName();
    },
    btnClass: function() {
        return getFirstBtn(this.class).buttonClass();
    },
    btnStyle: function() {
        return getFirstBtn(this.class).buttonStyle();
    }
});

Added: I'd strongly recommend you to create this button in the onCreated and store it in the template instance itself. You can later refer to it from helpers like this: Template.instance().FirstBtn.buttonName() for example.