(parentElm, oldCh, newCh, insertedVnodeQueue, removeOnly)
| 4827 | } |
| 4828 | |
| 4829 | function updateChildren (parentElm, oldCh, newCh, insertedVnodeQueue, removeOnly) { |
| 4830 | var oldStartIdx = 0; |
| 4831 | var newStartIdx = 0; |
| 4832 | var oldEndIdx = oldCh.length - 1; |
| 4833 | var oldStartVnode = oldCh[0]; |
| 4834 | var oldEndVnode = oldCh[oldEndIdx]; |
| 4835 | var newEndIdx = newCh.length - 1; |
| 4836 | var newStartVnode = newCh[0]; |
| 4837 | var newEndVnode = newCh[newEndIdx]; |
| 4838 | var oldKeyToIdx, idxInOld, elmToMove, refElm; |
| 4839 | |
| 4840 | // removeOnly is a special flag used only by <transition-group> |
| 4841 | // to ensure removed elements stay in correct relative positions |
| 4842 | // during leaving transitions |
| 4843 | var canMove = !removeOnly; |
| 4844 | |
| 4845 | while (oldStartIdx <= oldEndIdx && newStartIdx <= newEndIdx) { |
| 4846 | if (isUndef(oldStartVnode)) { |
| 4847 | oldStartVnode = oldCh[++oldStartIdx]; // Vnode has been moved left |
| 4848 | } else if (isUndef(oldEndVnode)) { |
| 4849 | oldEndVnode = oldCh[--oldEndIdx]; |
| 4850 | } else if (sameVnode(oldStartVnode, newStartVnode)) { |
| 4851 | patchVnode(oldStartVnode, newStartVnode, insertedVnodeQueue); |
| 4852 | oldStartVnode = oldCh[++oldStartIdx]; |
| 4853 | newStartVnode = newCh[++newStartIdx]; |
| 4854 | } else if (sameVnode(oldEndVnode, newEndVnode)) { |
| 4855 | patchVnode(oldEndVnode, newEndVnode, insertedVnodeQueue); |
| 4856 | oldEndVnode = oldCh[--oldEndIdx]; |
| 4857 | newEndVnode = newCh[--newEndIdx]; |
| 4858 | } else if (sameVnode(oldStartVnode, newEndVnode)) { // Vnode moved right |
| 4859 | patchVnode(oldStartVnode, newEndVnode, insertedVnodeQueue); |
| 4860 | canMove && nodeOps.insertBefore(parentElm, oldStartVnode.elm, nodeOps.nextSibling(oldEndVnode.elm)); |
| 4861 | oldStartVnode = oldCh[++oldStartIdx]; |
| 4862 | newEndVnode = newCh[--newEndIdx]; |
| 4863 | } else if (sameVnode(oldEndVnode, newStartVnode)) { // Vnode moved left |
| 4864 | patchVnode(oldEndVnode, newStartVnode, insertedVnodeQueue); |
| 4865 | canMove && nodeOps.insertBefore(parentElm, oldEndVnode.elm, oldStartVnode.elm); |
| 4866 | oldEndVnode = oldCh[--oldEndIdx]; |
| 4867 | newStartVnode = newCh[++newStartIdx]; |
| 4868 | } else { |
| 4869 | if (isUndef(oldKeyToIdx)) { oldKeyToIdx = createKeyToOldIdx(oldCh, oldStartIdx, oldEndIdx); } |
| 4870 | idxInOld = isDef(newStartVnode.key) ? oldKeyToIdx[newStartVnode.key] : null; |
| 4871 | if (isUndef(idxInOld)) { // New element |
| 4872 | createElm(newStartVnode, insertedVnodeQueue, parentElm, oldStartVnode.elm); |
| 4873 | newStartVnode = newCh[++newStartIdx]; |
| 4874 | } else { |
| 4875 | elmToMove = oldCh[idxInOld]; |
| 4876 | /* istanbul ignore if */ |
| 4877 | if (process.env.NODE_ENV !== 'production' && !elmToMove) { |
| 4878 | warn( |
| 4879 | 'It seems there are duplicate keys that is causing an update error. ' + |
| 4880 | 'Make sure each v-for item has a unique key.' |
| 4881 | ); |
| 4882 | } |
| 4883 | if (sameVnode(elmToMove, newStartVnode)) { |
| 4884 | patchVnode(elmToMove, newStartVnode, insertedVnodeQueue); |
| 4885 | oldCh[idxInOld] = undefined; |
| 4886 | canMove && nodeOps.insertBefore(parentElm, newStartVnode.elm, oldStartVnode.elm); |
no test coverage detected