Support other visuals' selection in custom slicer

Thank you, v-evelk 

Before I had received your answer I decided to build custom chart visual and filter dates programmaticaly there. After I had completed I returned to topic problem.

I describe steps to achieve the goal. It may be useful to someone.

1) Install powerbi-models using following command in project folder.

npm install --save powerbi-models

2) Add link to pbiviz.json.

"externalJS": [
    "node_modules/powerbi-models/dist/models.js"
  ]

3) Add link to tsconfig.json.

"files": [
    "node_modules/powerbi-models/dist/models-noexports.d.ts"
  ]

4) Add following code to update method. (The date to be selected should be under first (zero index) category.)

                    const conditions: IAdvancedFilterCondition[] = [
                        {
                            operator: "GreaterThanOrEqual",
                            value: new Date(startMillis) // First date.
                        },
                        {
                            operator: "LessThanOrEqual",
                            value: new Date(endMillis) // Last date.
                        }
                    ];
                    const categories: DataViewCategoricalColumn =
                        options.dataViews[0].categorical.categories[0];
                    const target: IFilterColumnTarget = {
                        table: categories.source.queryName.substr(
                            0, categories.source.queryName.indexOf('.')),
                        column: categories.source.displayName
                    };
                    const filter: IAdvancedFilter =
                        new window['powerbi-models']
                            .AdvancedFilter(target, "And", conditions);
                    this.visualHost.applyJsonFilter(
                        filter, "general", "filter", FilterAction.merge
                    );