Question

I have a client app that need to show a really big tree (It’s a mega organizational budget) , which is available via JSON queries – each budget section has a code , and s.t topic 1122 is the son of topic 11 and the father of topic 112233.

The budget tree begins with high level topics , and what I want to do is this : when a user click on a topic node (for example , “11”) , it will run a JSON query for all the sons of topic “11” , and then populate the tree with them.

So far I’ve managed to get the query to populate the tree with the high level nodes , but when you open a node , you get the same node list again.. 🙁

        XJSONDataSource yedaDS = new XJSONDataSource();
        yedaDS.setDataURL("http://api.yeda.us/data/gov/mof/budget/?o=jsonp&query=%7B%22code%22%20:%20%7B%20%22$regex%22%20:%20%22%5E0020%22%20%7D%7D");

        DataSourceTextField code = new DataSourceTextField("code","Code");
        code.setPrimaryKey(true);

        yedaDS.setTitleField("title");

        DataSourceIntegerField year = new DataSourceIntegerField("year", "Year");
        DataSourceTextField netAllocation = new DataSourceTextField("title","Title");

        yedaDS.setFields(code,year,netAllocation);

        TreeGrid remoteJsonQuery = new TreeGrid();

        remoteJsonQuery.setDataSource(yedaDS);
        remoteJsonQuery.setAutoFetchData(true);

        HStack stack = new HStack();
        stack.addMember(remoteJsonQuery);
        stack.draw();

Any ideas?

Answer 1

In your case, you need to have 3 main things in your DS –

1) An Id field for each row eg – 112233

2) The parent Id for that row — 1122 for this eg. You will have to add the foreign key relationship on this field. This is what you are missing

3) Root Value – 11, to tell the datasource which is/ are the root elements

As a code sample , look at the datasource code for this example, the important lines for you are –

DataSourceIntegerField employeeIdField = new DataSourceIntegerField("EmployeeId", "Employee ID");
employeeIdField.setPrimaryKey(true);
employeeIdField.setRequired(true);
DataSourceIntegerField reportsToField = new DataSourceIntegerField("ReportsTo", "Manager");
reportsToField.setRequired(true);
reportsToField.setForeignKey(id + ".EmployeeId");
reportsToField.setRootValue("11");