Bootstrap 4 dropdown with search

Question

How to implement the data-live-search="true" in bootstrap 4 dropdown?

Below link contained a good explanation, however it was for Bootstrap 3.

Bootstrap 3 select

Answer 1

I could not find a standard control and had 0 intention to use a library such as bootstrap select so I custom made this widget. Bootstrap 4 allows you to add forms inside your dropdown which is what I have used here. I added a search box, used an input event to capture the text entered by the user inside the box, If the phrase entered by the user starts with the items inside the box, I show the items else I hide them. I also handle the click event on any item to change the text of the dropdown button

//Initialize with the list of symbols
let names = ["BTC","XRP","ETH","BCH","ADA","XEM","LTC","XLM","TRX","MIOTA","DASH","EOS","XMR","NEO","QTUM","BTG","ETC","ICX","LSK","XRB","OMG","SC","BCN","ZEC","XVG","BCC","DCN","BTS","PPT","DOGE","BNB","KCS","STRAT","ARDR","SNT","STEEM","USDT","WAVES","VEN","DGB","KMD","DRGN","HSR","KIN","ETN","GNT","REP","VERI","ETHOS","RDD","ARK","XP","FUN","KNC","BAT","DCR","SALT","DENT","ZRX","PIVX","QASH","NXS","ELF","AE","FCT","POWR","REQ","AION","SUB","BTM","WAX","XDN","NXT","QSP","MAID","RHOC","GAS","LINK","GBYTE","MONA","SAN","ENG","ICN","BTCD","SYS","XZC","VEE","POE","TNB","PAY","DGD","WTC","PAC","ZCL","GNO","LEND","CVC","RDN","BNT","NEBL","GXS","ACT","DBC","ENJ","STORM","STORJ","GAME","VTC","COB","UKG","SKY","CND","SMART","NAV","CNX","XBY","MED","CMT","RPX","PLR","CTR","BAY","BLOCK","ANT","R","UBQ","SNM","MCO","AST","MANA","SNGLS","ITC","RCN","FLASH","AMB","DATA","EDG","ATM","XPA","DNT","RLC","PART","ADX","ST","TRIG","EMC2","WABI","BRD","ETP","BURST","XSH","DTR","BCO","WINGS","FUEL","ZEN","NULS","EMC","MOON","PPP","MGO","XCP","SRN","1ST","TNT","PPC","MOD","LBC","THC","LA","DCT","MLN","UTK","SPANK","RISE","CLOAK","XAS","EDO","CDT","DPY","QRL","WGR","MTL","GTO","AGRS","GVT","PRL","VIA","ADT","GRS","COSS","AEON","GRID","YOYOW","SHIFT","HST","VOX","MTH","INK","FTC","XSPEC","NYC","NLG","CFI","PRE","TRST","VIB","LUN","BNTY","SLS","GUP","EVX","SNOV","DLT","UNITY","JINN","MER","ECN","PURA","MINT","NLC2","POT","ZSC","TKN","HMQ","NMC","WRC","VIBE","AMP","DIME","PEPECASH","BITCNY","RVT","PPY","PASC","DAT","PRO","TIX","ION","BCPT","BLK","TAAS","COLX","NET","DMD","IOC","AIR","MDA","PAYX","MNX","STX","BITB","SIB","IXT","XEL","NMR","LRC","DRT","GRC","LMC","CRW","ELIX","HEAT","MSP","EXP","FAIR","XMY","SLR","OMNI","NEU","GOLOS","MUE","BTX","PHR","FLIXX","ONION","DIVX","HVN","PBL","OAX","XWC","MUSIC","ECC","BOT","ATB","DOVU","EAC","ARN","PKT","NEOS","ART","KICK","LKK","XRL","RADS","VRC","OK","VOISE","CREDO","POLL","SPRTS","TIPS","LINDA","PST","FLDC","NSR","PLBT","LOC","RBY","NXC","DBET","ZOI","HUSH","TGT","CAG","SBD","ALIS","PTOY","ECOB","XLR","COVAL","MYST","SWT","BIS","AVT","SNC","GCR","GAM","PINK","PRG","XNN","BLUE","QAU","BCAP","IFT","INCNT","POSW","FLO","IOP","XST","DNA","DTB","TIME","GEO","BMC","ORME","PIX","OTN","MYB","SPF","QWARK","OCT","ENRG","CRED","CLAM","ESP","CARBON","HDG","NIO","GMT","WILD","SOAR","WCT","PND","CAT","STAK","ODN","RMC","ABY","CURE","ICOS","BSD","BITUSD","OBITS","BBR","FRST","XPM","BET","XVC","SEQ","BCY","TX","DOPE","CSNO","CANN","XMCC","SUMO","WISH","OXY","SPR","BTM","TFL","BQ","DICE","LEO","OPT","UNO","NVST","SPHR","SNRG","XUC","PRIX","DBIX","PFR","PLU","NTRN","ATMS","SSS","SYNX","ALQO","PTC","BWK","1337","HYP","2GIVE","ETT","SEND","UFR","ZNY","RUP","MEME","DOT","DRP","GLD","REAL","GBX","BELA","TCC","VSX","CRC","BRX","VRM","CRB","SXC","LUX","ITNS","XAUR","AUR","UNIT","QRK","INXT","UFO","B2B","IXC","AC","START","KORE","BRK","BTDX","SCL","XBC","PIRL","IND","TZC","RIC","ARC","BUZZ","QVT","ZEIT","NVC","INN","BDL","HBT","HGT","HWC","REX","NOTE","EXCL","BLITZ","PURE","NOBL","MTNC","VIVO","FYP","BBT","CHC","XTO","ERO","APX","EDR","USNBT","VSL","CRAVE","EBST","ASTRO","TOA","FOR","ADST","CHIPS","VTR","BTCZ","BPL","ERC","808","PZM","PDC","TRUST","XMG","ZEPH","DYN","LIFE","PUT","BON","ADC","BUN","XCN","UNIFY","SMART","TRC","CREA","MAG","EGC","CVCOIN","EQT","WDC","ANC","GOOD","HOLD","FRD","ATS","B3","ELTCOIN","LDOGE","HUC","TKS","DGPT","FJC","SWIFT","ATL","XFT","REC","ONG","XGOX","PKB","MXT","ELLA","CFT","KRB","AHT","MBRS","DNR","PING","RKC","RNS","DCY","EBTC","YOC","GIM","MZC","MCAP","ZRC","BLU","ETBS","EFL","FST","NET","FLT","CTX","ARC","GCC","XCPO","CBX","TTC","MOIN","PBT","HAT","GUN","BASH","NKA","IFLT","LINX","EBET","FLIK","DP","EPY","BLAS","DFT","MEC","ENT","SMC","OCL","RAIN","STA","KLN","GRE","V","UIS","ALT","EFYT","GRWI","XLC","FYN","STU","CMPCO","DAXX","CFD","DAR","MRT","UNB","OTX","LANA","KEK","PIPL","ZET","ZER","BYC","NDC","LGD","TRUMP","BTA","ADL","XPTX","INFX","ERC20","KURT","NUKO","DGC","FCN","BRO","INSN","XPD","VISIO","TRCT","FC2","CDN","ABJ","SGR","BBP","ZENI","HTC","DAI","WHL","RC","STRC","Q2C","TRI","ATOM","I0C","SIFT","SMLY","TES","MAC","ZCG","NETKO","KLC","ADZ","PROC","ICOO","DSR","TIT","XBL","CRM","LOG","ELE","PIGGY","SAGA","UTC","EMV","MNE","JNS","MCRN","CCT","CJ","ACC","CPC","TOKEN","WGO","XIOS","NYAN","BTCS","PASL","SIGT","MNC","AU","SKIN","TROLL","BITS","CNT","XCXT","GB","FUCK","HBN","8BIT","YTN","ROC","42","MAX","B@","USC","SOON","SDRN","BTB","BPC","KOBO","RIYA","HODL","ORB","NTO","CCN","TRK","PXC","HPC","DEM","DIX","CNO","VIDZ","GAIA","DSH","RBT","ONX","OPAL","BRIT","CV2","HAL","RED","4CHN","C2","TKR","BUCKS","XPY","DRXNE","XHI","POS","ARI","TRDT","LBTC","SDC","BTCRED","CORG","WTT","TAG","ETG","ALTCOM","XJO","EVIL","KUSH","XRA","PCOIN","VOT","BCF","DDF","FNC","AMMO","BOLI","PAK","CCO","MARS","VLT","RLT","BIGUP","SPACE","MONK","CUBE","XCT","EGAS","PR","SUPER","RBX","UNY","TEK","LCP","EMD","GAP","BLC","ITI","NTWK","UNIC","JET","CCRB","GRIM","TSE","LTB","CAT","EOT","ICOB","CHESS","BTSR","COAL","MAD","888","AMS","KRONE","POST","MOJO","XGR","VAL","BITBTC","KAYI","WYV","ZZC","BSTY","DFS","MNM","PXI","EL","SLG","BERN","BTWTY","HERO","EBCH","CRX","DALC","QTL","SWING","STV","EUC","KED","TGC","VUC","MAR","ECASH","STARS","ERY","ZUR","ETHD","CMT","BAS","EREAL","SOIL","HNC","BRAT","GTC","IMS","CNNC","SHDW","BNX","ARG","SRC","GLT","BTG","PX","XVP","NRO","MAO","IETH","MOTO","XRE","MTLMC3","ICN","UNITS","HONEY","AERM","PHS","EVO","CACH","FUNC","SPEX","CON","HXX","HMP","XCO","EAGLE","611","ECO","DUO","GP","FLAX","XCRE","REE","ZMC","BITSILVER","CPN","SCORE","GPU","ACOIN","USDE","BUMBA","CXT","XCS","$$$","ARCO","RPC","MST","SPT","BLN","FIRE","JIN","SFC","BIP","TAJ","QCN","GPL","XBTS","RBIES","NEVA","RUPX","BOAT","VPRC","BENJI","MAY","SONG","OFF","ALL","CWXT","E4ROW","300","ASAFE2","BTPL","FUZZ","BSTAR","IMX","MSCN","LUNA","ICON","CTO","WBB","PLACO","COXST","SLEVIN","CTIC3","UET","CF","DRS","EXN","PEX","ARGUS","TYCHO","PIE","BITEUR","URC","PRX","PRC","PLNC","DOLLAR","BTQ","ROOFS","WOMEN","ATX","BRAIN","SOCC","GEERT","XBTC21","QBC","ZYD","LTCU","RIDE","VLTC","MILO","VIP","DIBC","LTCR","ACP","FXE","CRDNC","VRS","ELS","JS","AGLC","KNC","LIR","ZNE","LVPS","JOBS","HVCO","CTIC2","SANDG","XRC","CRTM","MGM","IBANK","NODC","P7C","VOLT","CREVA","TSTR","SLFI","NANOX","GSR","XNG","HMC","EBT","DGCS","DMB","ABN","ECA","PHO","GCN","VTA","PGL","RUSTBITS","YASH","INPAY","FIMK","ITT","CRYPT","FUNK","SHORTY","BLOCKPAY","POP","CASINO","LNK","LOT","MBI","METAL","ITZ","BXT","STS","AMBER","MRJA","BTCR","UNI","WAY","BRIA","SCRT","BLZ","GLC","GRT","BITZ","NEWB","AIB","MUT","SH","J","FRC","ISL","FLY","SLING","CYP","RMC","TALK","ICE","FRK","MEOW","WMC","SAC","VC","BITGOLD","YAC","ANTI","WORM","LEA","DLC","BOST","VEC2","WARP","GCC","URO","DES","FLVR","QBK","DBTC","BVC","MND","DRM","STEPS","BLRY","JWL","TOR","GBT","ARB","PULSE","ADCN","RSGP","G3N","EGO","BIOS","CASH","MRNG","MTM","IMPS","ORLY","BSC","DLISK","SCS","CRT","OS76","PONZI","CESC","XOC","TAGR","ALTC","CAB","SDP","BIOB","FRAZ","GBC","CCM100","LEX","CONX","SOJ","ULA","PIZZA","OCEAN","CALC","APW","ATMC","NAS","GNX","SMT","BIX","GTC","BCD","MOT","QLC","SPHTX","TSL","HTML","AMM","CAT","QBT","PRO","HPY","ACE","BCX","INF","CAPP","NGC","SHND","SBTC","ENT","MKR","DIM","B2X","FRGC","LLT","CMS","VIU","DEW","WC","UGT","XTZ","MDS","CLUB","IRL","AI","CMS","BIG","HBC","HTML5","FIL","IGNIS","EAG","GBG","BTCA","XID","ESC","BCDN","PAYP","TOK","IFC","LBTC","UQC","VASH","KBR","BSR","BTE","EXRN","XIN","GRX","UBTC","CPAY","MAGE","PLAY","KARMA","MAGN","SAFEX","ANI","SFE","QBT","FDX","SBC","ZENGOLD","TIE","GBRC","GAIN","STAR","PEC","BEST","MGC","TER","DAV","PCN","PYLNT","SHA","NEOG","PLC","ACES","WAND","SISA","MARX","SUR","MONEY","COUPE","FLAP","SIGMA","TOP","BOS","SJCX","DMC","TURBO","MSD","MINEX","ETT","MTX","CYC","VULC","ACC","THS","GAY","WIC","XSTC","LTG","BTCS","SCT","FONZ","BT1","SKR","WOW","ZBC","FAZZ","UR","DON","DAY","TRIA","HDLB","WINK","BT2","CMP","IQT","SAK","BITOK","FUDD","PLX","PRN","PNX","BTCM","MCI","EUSD","FRN","EDRC","ELITE","EVC","UAHPAY","RYZ","SKC","DUTCH","EVR","XTD","NTC","TELL","HIGH","WSX","YES","ZSE","FFC","LEPEN","RCN","HALLO","BXC","INDIA","EGOLD","COR","BLX","ASN","PRES","NAMO","UNRC","OX","GOLF","FID","APC","CYDER","GLS","GRN","RUNNERS","REGA","BTC2X","BTBc","ANTX","SND","PCS","UNC","TODAY","GMX","ABC","CHEAP","DISK","WA","PRIMU","MCR","X2","ELC","PDG","HYTV","BSN","ACN","POKE","AKY","DEUS","CASH","LAZ","SKULL","RUPX","CC","HNC","MONETA","ROYAL","QORA","MAVRO","BIRDS","FAP","TCOIN","EBIT","KASHH","LDCN","XOT","CME","BLAZR","GARY","IBTC","LKC","NBIT","SPORT","DBG","STEX","YEL","BUB","IPY","TEAM","AXIOM","PRM","ELTC2","BITCF","GML","SNAKE","UTA","9COIN","HYPER","AV","XVE","10MT","FUTC","XQN","LTH","RUBIT","BIT","TLE","SHELL","XDE2","FBL","CBD","FRWC","DASHS","DUB","MMXVI","OMC","FC","PSY","OP","TOPAZ","RICHX","SWP","TCR","HCC","TRICK","BAC","IVZ","XAU","MEN","OPES","XID","VOYA","MBL","BET","BAT","RBBT","BGR","EGG","DCRE","TESLA","TERA","RHFC","GUC","ADK","XRY","EMB","CSC","OCOW","BTU","XYLO","STC","QC","FRCT","MDC"]

//Find the input search box
let search = document.getElementById("searchCoin")

//Find every item inside the dropdown
let items = document.getElementsByClassName("dropdown-item")
function buildDropDown(values) {
    let contents = []
    for (let name of values) {
    contents.push('<input type="button" class="dropdown-item" type="button" value="' + name + '"/>')
    }
    $('#menuItems').append(contents.join(""))

    //Hide the row that shows no items were found
    $('#empty').hide()
}

//Capture the event when user types into the search box
window.addEventListener('input', function () {
    filter(search.value.trim().toLowerCase())
})

//For every word entered by the user, check if the symbol starts with that word
//If it does show the symbol, else hide it
function filter(word) {
    let length = items.length
    let collection = []
    let hidden = 0
    for (let i = 0; i < length; i++) {
    if (items[i].value.toLowerCase().startsWith(word)) {
        $(items[i]).show()
    }
    else {
        $(items[i]).hide()
        hidden++
    }
    }

    //If all items are hidden, show the empty view
    if (hidden === length) {
    $('#empty').show()
    }
    else {
    $('#empty').hide()
    }
}

//If the user clicks on any item, set the title of the button as the text of the item
$('#menuItems').on('click', '.dropdown-item', function(){
    $('#dropdown_coins').text($(this)[0].value)
    $("#dropdown_coins").dropdown('toggle');
})

buildDropDown(names)

.dropdown {
  margin: 20px;
}

.dropdown-menu {
  max-height: 20rem;
  overflow-y: auto;
}

<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta.2/css/bootstrap.css" />
<link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/font-awesome/4.7.0/css/font-awesome.min.css" />
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.0.0-beta.2/js/bootstrap.bundle.min.js"></script>
   
<div class="dropdown">
    <button class="btn btn-secondary dropdown-toggle" type="button" id="dropdown_coins" data-toggle="dropdown" aria-haspopup="true"
        aria-expanded="false">
        Coin
    </button>
    <div id="menu" class="dropdown-menu" aria-labelledby="dropdown_coins">
        <form class="px-4 py-2">
            <input type="search" class="form-control" id="searchCoin" placeholder="BTC" autofocus="autofocus">
        </form>
        <div id="menuItems"></div>
        <div id="empty" class="dropdown-header">No coins found</div>
    </div>
</div>
        

UPDATE 1

The code above uses show() and hide() inside a loop which is why the UI is slow when you clear everything you typed in case you didn't notice. Instead of that, use .css({display: 'none'}) and .css({display: 'block'})

Answer 2

As of version 1.13.1 there is support for Bootstrap 4: https://developer.snapappointments.com/bootstrap-select/

The implementation remains exactly the same as it was in Bootstrap 3:

• add class="selectpicker" and data-live-search="true"to your select
• add data-tokens to your options. The live search will look into these data-token element when performing the search.

This is an example, taken from the site of the link above:

<select class="selectpicker" data-live-search="true">
  <option data-tokens="ketchup mustard">Hot Dog, Fries and a Soda</option>
  <option data-tokens="mustard">Burger, Shake and a Smile</option>
  <option data-tokens="frosting">Sugar, Spice and all things nice</option>
</select>

Live search for the search term 'fro' will only leave the third option visible (because of the data-tokens "frosting").

Don't forget to include the bootstrap-select CDN .css and .js in your project. I am very glad to see this live search become available again, because it comes in very handy when presenting large dropdown lists to the user.