FireOnce Prop

[NehemiahK]

It would be nice if you could pass in a prop for a waypoint to only fireOnce, afterwards it wouldn't fire again. I made my own wrapperelement because the use case has come up quite a bit. It should be a fairly simple implementation and would be quite useful. Alternatively you could have a fireCount prop in which you can state how many times the waypoint can fire onEnter/leave

[trotzig]

I think this would make sense -- I'd be happy to accept a PR adding support for this usecase. In the meantime, do you want to share what your wrapper looks like? It might help others who land here. :)

[NehemiahK]

@trotzig I could potentially make a PR, I'll need to dig around in the code. Would you want a fireCount or a fireOnce prop?

This is the current workaround implemented. (This was specifically done for onEnter, to work for onLeave it could be done similarly, would just need a bit of extra work)
`

import React from 'react'
import Waypoint from 'react-waypoint';

class HtWaypoint extends React.PureComponent{
    constructor(props){
        super(props);

        this.state = {firstLoad:true};
    }

    enter = (cb) => {
        if(this.props.fireOnce && !this.state.firstLoad)return;
        this.setState({firstLoad:false})
        cb();
    }

    render(){
        let {onEnter,...waypointProps} = this.props;
        return(
            <Waypoint onEnter={() => this.enter(onEnter)} {...waypointProps}>
                {this.props.children}
            </Waypoint>
         )
    }


}

HtWaypoint.defaultProps = {fireOnce:false,onEnter: ()=>{}};

export default HtWaypoint

[trotzig]

Thanks! I think I'd prefer the fireOnce option. I don't see a clear use-case for the count so a boolean should do.

[NehemiahK]

@trotzig follow up, if you implement fireOnce and you passed in onLeave, the onLEave function would never fire? What would make sense to you

[trotzig]

In your use-case, it wouldn't make sense to fire onLeave, right? In that case, we could just add that behavior to the documentation (README file).

[NehemiahK]

Sorry, to clarify, would fireOnce prop stop onLeave from firing? Since it wouldn't make sense to pass in the onLeave prop if you are passing in fireOnce. I

[trotzig]

Yep, that was how I interpreted the feature! If people come across the fireOnce property and need the onLeave as well, we can just change the behavior in a later PR.