我的树图的 Arangodb 自定义过滤器/访问者 [英] Arangodb custom filter/visitor for my tree graph

问题描述

我有一个有两个边定义的图，如下所示:

I have a graph with two edge definitions like this:

isDepartment: [organisation] -> [organisation]
hasAccess: [user] -> [organisation]

组织嵌套在树中(无循环).有多个没有任何传入 isDepartment 边的顶级组织.

Organisations are nested in a tree (no cycles). There are multiple top-level organisations without any incoming isDepartment edges.

用户被授予访问一个或多个组织的权限.这些可以是顶级组织，也可以是树下某处的组织.如果用户有权访问某个组织，则它可以访问所有子组织.

Users are granted access to one or more organisations. These can be top-level organisations or organisations somewhere lower down the tree. If a user has access to an organisation, it has access to all child organisations.

我正在尝试构建一个自定义访问者或过滤器，为用户提供所有可访问的组织，包括它的根路径，以及是否可访问的属性.

I am trying to build a custom visitor or filter that gives me all accessible organisations for a user, including it's path to the root, along with a property if they are accessible or not.

例如，采取以下组织结构:

Example, take the following organisation structure:

• 根A
  • 部门A.1
  • 部门A.2
  • 部门B.1
  • 部门B.2
  • 分部B.2.1
  • 部门C.1
  • 部门C.2

  现在以一个具有Root A 和Dept 访问权限的用户为例.B.2.我想生成以下结果树:

  Now take a user that hasAccess to Root A and Dept. B.2. I would like to generate the following result tree:

  • Root A，可访问:true
    • 部门A.1，可访问:true
    • 部门A.2、可访问:true
    • 部门B.2、可访问:true
    • 分部B.2.1，可访问:true

    注意Root C和Dept.B1 不在结果中，因为用户无法访问它们，也无法访问它们的任何子节点.

    Note that Root C and Dept. B1 are not in the result because they are not accessible to the user, nor are any of their children accessible.

    另请注意，Root B 已包含在内，但被标记为不可访问.这是因为用户仅被授予对 Root B 的子代的访问权限，而不能访问 root 本身.

    Also note that Root B is included but marked as not accessible. This is because teh user is granted access to only a child of Root B but not the root itself.

    如何编写自定义函数/访问者/过滤器来完成此任务?

    How can I write a custom function/visitor/filter that accomplished this?

    推荐答案

    这确实是一个具有挑战性的问题，非常感谢 ;)

    This was indeed a challenging question, thank you very much ;)

    您可以通过向 AQL 添加用户定义的函数并在 TRAVERSER 中使用它们来解决此问题.

    You can solve this by adding user-defined functions to AQL and use them in the TRAVERSER.

    首先我通过arangosh注册了两个AQL访问者函数:

    First of all I have registered two AQL visitor functions through arangosh:

    var aqlfunctions = require("org/arangodb/aql/functions");
    aqlfunctions.register("myvisitor::indirectAccess", "function (config, result, vertex) { if(result.length === 0) {result.push({});} result[0][vertex._key] = {hasAccess: true};}")
    aqlfunctions.register("myvisitor::noAccess", "function (config, result, vertex) { if (result.length === 0) {result.push({});} result[0][vertex._key] = {hasAccess: false};}")
    

    这些函数只需执行以下操作:

    These functions simply do the following:

    • myvisitor::indirectAccess 将用于向下遍历树.由于在 AQL 中结果始终是一个 Array，我们只需在第一个文档中(如果需要)来存储所有数据.然后我们将值 {hasAccess: true} 分配给顶点 _key 属性.
    • myvisitor::noAccess 将用于遍历树并以相同的方式存储 '{hasAccess: false}`.
    • myvisitor::indirectAccess will be used to traverse down the tree. As in AQL the result is always an Array, we simply at a first document to it (if necessary) to store all the data. Then we assign to the vertexes _key property the value {hasAccess: true}.
    • myvisitor::noAccess will be used to traverse up the tree und will store '{hasAccess: false}` in the same way.

    现在我们可以执行以下使用这些访问者的查询:

    Now we can execute the following query which makes use of these visitors:

    FOR x IN GRAPH_NEIGHBORS(@graph, @userId, {direction: 'outbound'})
    LET upwards = TRAVERSAL(organisation, isDepartment, x, 'inbound', {visitor: 'myvisitor::noAccess'})[0]
    LET downwards = TRAVERSAL(organisation, isDepartment, x, 'outbound', {visitor: 'myvisitor::indirectAccess'})[0]
    RETURN MERGE(upwards, downwards)
    

    简短说明:

    1. 查找该用户可以直接访问的组织.
    2. 上树upwards并将所有内容标记为noAccess".
    3. 沿着树向下向下走，并将所有内容标记为访问".
    4. 合并向上和向下.
    1. Find the organizations this user has direct access to.
    2. Go up the tree upwards and mark everything as "noAccess".
    3. Go down the tree downwards and mark everything as "access".
    4. Merge upwards and downwards.

    如果您想修改结果格式，您必须更改已注册的访问者功能.

    If you would like to modify the result format you have to change the registered visitor functions.

    这篇关于我的树图的 Arangodb 自定义过滤器/访问者的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！