2024-01-09 - Frontend GraphNav requesting relNodes

Frontend SitePage Element - GraphNavigation

graphNavigation useRef

• graphNavigation has Ref focusedNodes that stores array of focused nodes for each graphNav
• graphNavigation has Ref nodesRequested for all nodes sent relNode request to backend (so not double up requests)

initialNodes processing

• initialNodes sets focusedNodes for each graphNav as all initialNodes shown in that graphNav (objTypes)
• initialNodes setGraphNode(s)
• setGraphNode triggers a useEffect that newNodeAdded

newNodeAdded useEffect

• check nodesRequested if already sent request to backend?

for each GraphNav start

• check this node shown in that graphNav (objTypes)
• find shortest # hops to newNode from all focusedNodes
• if shortest hops is < graphNav hopLimit, need to request backend

for each GraphNav end

if any graphNav need to request backend

• check nodesRequested if already sent request to backend again, in case updated during processing (?)
• add to nodesRequested
• send request

after get backend result

for each relNode

• setGraphRelationship
• setGraphNode (must do after setGraphRelationship)
• setGraphNode triggers a useEffect that newNodeAdded

for each GraphNav start

• check this node shown in graphNav (objTypes)
• check this relationship Type shown in graphNav
• find shortest # hops to newNode from all focusedNodes
• if shortest hops is < graphNav hopLimit, setGraphRelationshipsPerGraphNav and setGraphNodesPerGraphNav

for each GraphNav end for each relNode end

graphNav change focus

• when a graphNav changes focus we need to remove from graphRelationshipsPerGraphNav and graphNodesPerGraphNav any that are > hopLimit
• add new relNodes that are < hopLimit
• request new relNodes that have not been requested yet

Process

• graphNav updates graphNavigation focusedNodes reference
• triggers useEffect that recalculates graphRelationshipsPerGraphNav and graphNodesPerGraphNav for that graphNav
• if need to request new relNodes trigger useEffect newNodeAdded for leaf node
• (a little inefficient because will run all tests on that leaf node, even though we already know it needs to be requested, perhaps create another useEffect that is a forced request/skips tests, share code for requesting from backend and result)

old notes

requesting relNodes from backend

• have standard recursive function that receives graphNodeId, name: getRelNodes(graphNode, hops)
• in top level GraphNavigation compenent
• graphNodeId object has a property storing how many hops this node is from currently focused node
• probably not reference any state in getRelNodes because state might not be updated or could be stale, send all required values as params
• if reached limit of hops stop
• if graphNodeId already exists in nodesRequested can stop processing
• set graphNodeId in nodesRequested
• send request to backend
• after get response do most processing inside setGraphNodes and setGraphRelationships so working with latest State
• use cancelToken on backend request, maybe need code to check if cancelled so not adjust state on cancelled/unmounted request

setGraphNodes

• check in graphNodes if hops for node still matches, if not use updated hops from State
• add new nodes to graphNodes
• if not yet reached hops limit, invoke getRelNodes for new nodes

setGraphRelationships

• add new relationship to graphRelationships if not already exist

Change focused node

• handled in GraphNav compenent so all elements do nto re-render when traversing graph
• if detect more must request more nodes using getRelNodes, have a state prop passed down from GraphNavigation compenent that triggers getRelNodes function

idea 1

• reset all nodes to 0 hops from focused node
• traverse graph from focused node using graphRelationships
• update hops property
• if reach node that has not yet requested relationships (set to null) and not reached hop limit, invoke getRelNodes in parent GraphNavigation component
• (later) can remove nodes too distant from focused node here if want to cleanup ram (but must consider all child GraphNav elements)

idea 2

• create a list of nodes and relationships only up to number of hops shown in this GraphNav component
• when change focus (or parent graphNodes/graphRelationships updates) empty this list and rebuild from currently focused node