How to check if a user JID is already taken in XMPPFrameWork

Question

I am kind of new to xmppframework. I have a quick question. Is it possible to know if a certain JID is available or no. In other words is it possible to check that the username is already associated or registered with certain account.

Answer 1

with jabber search yes you can search and find user with specific jID or userName or ...

in here i create function that take some jID as a parameter and the server response to you as a query and inside that query if anythings match there will be items that contains user with matching jID

func xmppQueryForSearchPacket(forJID jid: String) {
    let searchingServer = "search.something" //something must replace with your xmpp domain name
    let query = DDXMLElement(name: "query", xmlns: "jabber:iq:search")
    let x = DDXMLElement(name: "x", xmlns: "jabber:x:data")
    x.addAttribute(withName: "type", stringValue: "submit")


    let field1 = DDXMLElement(name: "field")
    let value1 = DDXMLElement(name: "value", stringValue: "jabber:iq:search")
    field1.addAttribute(withName: "type", stringValue: "hidden")
    field1.addAttribute(withName: "var", stringValue: "FORM_TYPE")
    field1.addChild(value1)


    let field2 = DDXMLElement(name: "field")
    let value2 = DDXMLElement(name: "value", stringValue: jid)
    field2.addAttribute(withName: "type", stringValue: "text-single")
    field2.addAttribute(withName: "var", stringValue: "search")
    field2.addChild(value2)

    //we just search in userNames

    let field3 = DDXMLElement(name: "field")
    let value3 = DDXMLElement(name: "value", stringValue: "1")
    field3.addAttribute(withName: "type", stringValue: "boolean")
    field3.addAttribute(withName: "var", stringValue: "Username")
    field3.addChild(value3)


    x.addChild(field1)
    x.addChild(field2)
    x.addChild(field3)
    query.addChild(x)


    let iq = XMPPIQ(iqType: .set, to: XMPPJID(string: searchingServer), elementID: XMPPStream.generateUUID, child: query)
   XMPPStream.send(iq)
}

the answer of that packet will come in a query form and you can receive it like this :

extension yourClassName: XMPPStreamDelegate {
    func xmppStream(_ sender: XMPPStream, didReceive iq: XMPPIQ) -> Bool {
        let searchingServer = "search.something"
        if iq.from?.bare != searchingServer {
            return true
        }
        return false
    }
}

for more information please reade XEP-0055.