Pharo, Voyage and MongoDB

Question

I want to build a relatively simple web app using Pharo, Voyage and MongoDB + TeaPot. Before I start the project I did a lot of research and one question remains: How do I initially upload a bunch of data into the MongoDB? I basically have the data in CSV format. Do I have to program an importer in Smalltalk that does that? If I were to do it without smalltalk it would be missing all the object IDs etc. How do you go about things like that?

Thanks, Henrik

Answer 1

If you have data in CSV format, then I would recommend creating a simple importer. You could use NeoCSV and then save it via Pharo. I presume you know how to setup Mongo repository (@workspace) do:

| repository |
repository := VOMongoRepository 
              host: VOMongoRepository defaultHost 
              database: 'MyMongoDb'.
VORepository setRepository: repository.

First create your two class methods for Voyage:

Kid class >> isVoyageRoot
    ^ true "instances of this object will be root"

Kid class >> voyageCollectionName
    ^ 'Kids' "The collection name in MongoDB"

The Kid class should have firstName(:), surname(:), age(:) accesors and instance variables of the same name.

Then simply have a reading from CSV and then saving it into mongoDB:

| personalInformation readData columnName columnData aKid |
"init variable"
personalInformation := OrderedDictionary new.
"emulate CSV reading"
readData := (NeoCSVReader on: 'firstName, surname, age\John, Smith, 5' withCRs readStream) upToEnd.
columnName := readData first.
columnData := readData second.
"Repeat for as many number of columns you may have"
1 to: columnName size do: [ :index |
    personalInformation at: (columnName at: index) put: (columnData at: index)
].
aKid := Kid new.   
"Storing Kid object information"
personalInformation keysAndValuesDo: [ :key :value |
    aKid perform: (key asString,$:) asSymbol with: value "For every column store the information into a Kid object (you have to have accessors for that)"
].
aKid save "Saving into mongoDB"

This is only to give you rough idea

To query in your MongoDB do:

db.Kids.find()

You should see the stored information.

Disclaimer: Even thou the code should be fine, I did not have time to actually test it on mongoDB.