Home / Blog

In MyOwnDB , there's an CrosstabObject inheriting from ActiveRecord, but that doesn't correspond to any table in the database (actually, it is configured to map to a table in the database as this is mandated by AR, but it's never used like that). It is only used to select data with find_by_sql.

Now, some columns of the data returned by the query can be data that has been serialized to YAML, but each query has its own set of serialized columns.

I first tried to call the serialize method provided by rails, but it didn't work. I suspect the ActiveRecord model needs the column to exist when it is initialized for the serialization to be activated, which is not the case here as the CrosstabObject is mapped to an object that doesn't have the columns returned by the sql query.

In this example, the query returns a result set which has the test_attach column serialized to YAML. test_attach is not a column of the table to which CrosstabObject was mapped. As you can see, the serialization is configured, but has no effect on the returned data:

If I redefine the test_attach accessor on list[6] 's singleton class, I get the expected result though:

As each query has its own set of serialized columns, what I want to do is just pass the list of columns that contain serialized data, so that the accessors get defined, which is easily done by adding a method to CrosstabObject:

which enables me to easily configure the columns returned by the sql query that are serialized:

YUI2's Datatable is a great widget I use in MyOwnDB and here's a small tip for when you use it to load a remote data source .

In that case, the datatable is getting the data to display from a YUI2 DataSource that has been configured with the URL to use when fetching the data requested by the datatable.

When instanciating the datatable, you can pass it a configuration object, with amongst other option, the initialRequest that should be sent by the associated datasource when the datatable is displayed for the first time. initialRequest is a string that is simply appended to the URL passed to the DataSource.

So if your datasource URL is "http://www.myurl.com?all=true", and your initialRequest is "sort=name", the request sent by the DataSource will be for the URL "http://www.myurl.com?all=truesort=name", which is clearly not good.

The solution here is to either be sure that the datasource URL ends with a ? or a &, or to always start the initialRequest with &.

The second option is the easiest in my case.

I'm available for hire 

If you're looking for someone to temporarily join your IT team, or if you need help to put IT to work in your company, I'm ready to help. Contact me now !

Mon Tue Wed Thu Fri Sat Sun
    1 2 3 4 5
6 7 8 9 10 11 12
13 14 15 16 17 18 19
20 21 22 23 24 25 26
27 28 29 30 31