graflow: better (live) implementation of getLink + warning anti dbl-link

bzGraflow.js

@@ -402,9 +402,13 @@ class BZgraflow extends Buildoz{
         return(this.stagedNodes[nid])
     }
 
-    addWire(link){ console.log('addWire', link)
+    addWire(link){ 
         const [idNode1, idPort1] = link.from
         const [idNode2, idPort2] = link.to
+        if(this.getLink(idNode1,idNode2)) {
+            console.warn('Current version of graflow does not allow multiple wires between same nodes',this.getLink(idNode1,idNode2),idNode1,idNode2)
+            return
+        }
         const path = this.linkNodes(idNode1, idPort1, idNode2, idPort2)
         const id  = `${idNode1}_${idNode2}`
         this.stagedWires[id] = document.createElementNS('http://www.w3.org/2000/svg', 'path')
@@ -414,6 +418,7 @@ class BZgraflow extends Buildoz{
         if(this.arrowDefs && link.startArrow) this.stagedWires[id].setAttribute('marker-start','url(#arrow)')
         this.stagedWires[id].classList.add('bzgf-wire')
         this.stagedWires[id].dataset.id = id
+        this.stagedWires[id].link = link
         this.wiresContainer.append(this.stagedWires[id])
         if(!this.flow.links.find(l => l.from[0] === idNode1 && l.from[1] === idPort1 && l.to[0] === idNode2 && l.to[1] === idPort2)) {
             this.flow.links.push(link)
@@ -1022,12 +1027,9 @@ class BZgraflow extends Buildoz{
     }
     
     getLink(nid1, nid2){
-        let lnk = null
-        lnk = this.flow.links.find(item => ((item.from[0]==nid1) && (item.to[0]==nid2)))
-        if(!lnk) {
-            lnk = this._virtualLinks?.get(`${nid1}__${nid2}`)
-        }
-        return(lnk)
+        const wire = this.stagedWires[`${nid1}_${nid2}`]
+        if(wire?.link) return wire.link
+        return this._virtualLinks?.get(`${nid1}__${nid2}`) ?? null
     }
 
     buildGraphStructures(nodes, links, includeLinkIndexes = false) {