Applying a queryRewrite filter only if a certain dimention exists

[djrmarques]

Problem I would like to use the queryRewrite method to filter by the values of a certain dimension, but only if this dimension exists on a certain cube.

I wrote a small js function that I call within the queryRewrite method that validates if there is a dimension dimension in a cube with name cubeName. This function will then go through all my models and check if such cube with the specific dimension exists.

This seems a bit hacky though, so I was wondering if there was a better way of achieving this (by this I mean, if I specify a filter to a dimension that does not exist on the cube, this filter is just ignored instead of raising an error).

// Checks if a certain cube contains a given dimension. Returns a boolean
// folder is the folder where all the models are
function checkIfDimensionExists(cubeName, dimension, folder) {
  for (const file of fs.readdirSync(folder).filter(f => f.endsWith(".yml"))) {

    // Load yaml file
    const yamlCubes = yaml.load(fs.readFileSync(path.join(folder, file), 'utf8'))['cubes']

    // Check if the dimension exists
    for (const cube of yamlCubes) {

      if ((cube.name === cubeName) && cube.dimensions.filter(d => d.name === dimension).length > 0) {
        return true
      }
    }
  }
  return false
}

Just as an example of what my queryRewrite method might look like:

  queryRewrite: (query, { securityContext }) => {
    const dimension = "tenant"

    // TODO: This needs to be improved, as it only works on queries like `query={"measures":["cubeName.count"]}`
    const cube = query['measures'][0].split('.')[0]

    // Only applies a query rewrite if a dimension exists on the cube
    if (checkIfDimensionExists(cube, dimension, "/cube/conf/model")) {
      query.filters.push({
        member: cube + '.' + dimension,
        operator: "equals",
        values: [securityContext.tenant],
      });
    } else {
      console.log(`Dimension: ${dimension} does not exist on Cube: ${cube}`)
    }
    console.log(`Final Query: ${query}`)
    return query;
  },