User:Enterprisey/mark-join-date.js

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This user script seems to have a documentation page at User:Enterprisey/mark-join-date.

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$( function() {
    if( mw.config.get( "wgPageName" ).indexOf( "Wikipedia:Sockpuppet_investigations/" ) >= 0 ) {
        var allLinks = Array.from( document.querySelectorAll( "a[href^='//en.wikipedia.org/wiki/User:'].external" ) );
        var CHUNK_SIZE = 10;
        for( var i = 0; i < allLinks.length; i += CHUNK_SIZE ) {
            fetchAndDisplayDates( allLinks.slice( i, i + CHUNK_SIZE ) );
        }

        // Make an API call to fetch all registration dates for users in this chunk
        function fetchAndDisplayDates( links ) {

            // Make the "ususers" parameter for the query;
            // must be pipe-separated URL-encoded usernames
            var usersParam = links.map( function ( link ) {
                    return encodeURIComponent( link.href.substr( 35 ) ); } )
                .join( "|" );

            // Perform query
            ( new mw.Api() ).get( {
                "list": "users",
                "ususers": usersParam,
                "usprop": "registration"
            } ).done( function ( res ) {
                if( res && res.query && res.query.users ) {
                    for( var j = 0; j < CHUNK_SIZE; j++ ) {
                        dateSpan = document.createElement( "span" );
                        dateSpan.style.fontSize = "80%";
                        dateSpan.style.padding = "0 0.2em";
                        dateSpan.textContent = res.query.users[j].registration;
                        links[j].parentNode.insertBefore( dateSpan, links[j].nextSibling );
                    }
                } else {
                    console.log( "bad data", res );
                }
            } );
        }
    }
} );