# Using YAML as a data DSL **URL:** \ **Category:** Ruby\ **Created:** [June 14, 2006, 7:30pm UTC](https://www.ruby-forum.com/t/using-yaml-as-a-data-dsl/63385 "2006-06-14T19:30:33Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![Jatinder\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e4f/32.png) [@Jatinder\_S](https://www.ruby-forum.com/u/Jatinder_S)\ **Post date:** [June 14, 2006, 7:30pm UTC](https://www.ruby-forum.com/t/using-yaml-as-a-data-dsl/63385/1 "2006-06-14T19:30:33Z")
I have an RoR application which has various GUI screens for taking input from users for creating some entities in my application. What ever information is given by the user I am putting in to a datastructure in ruby(I have created a set of classes in ruby for that purpose), To give you an example say there is a Music store and there are various records of various artists available. we can have following classes for storing the information entered by user for records and artists, class Record @name #array for storing objects of artist class @artists end class Artist @name @phone end Note: ofcourse we can use a db here and update the info entered by user directly in the database, but may be I am giving a wrong example here, actually the above information about entities is entered by user only once. Now I want to give the end user, a way to circumvent GUI and directly write in to a file the information about the entities in a format specified by me(thats what a DSL is all about). Following is what I intend to have with respect to DSL 1. This DSL would be more of a data DSL then a business DSL which is meant for defining business rules. 2. It should be user friendly(who doesn’t want a DSL to be user friendly) with these goals in mind I wrote an internal DSL(having ruby method calls) and wrote some code which populates above mentioned classes(Record and Artist). I worked in other direction of using YAML as DSL; for that I created a YAML compliant file with following contents, ########################### — !ruby/object:Video artist: Jatinder name: SampleVideo type: Pop ########################### YAML provides a way to persist objects in text format which is I believe very user friendly, so what I thought is that a user can create a file with above contents and then use YAML::load method to load above file’s content in to ruby object. Well in this case I really dont have to do much, as in I dont have to write a parser. There might be several deficiencies/probelms in the 2nd approach, few of them I think are, 1. YAML has a strict format, even if a “:” goes here and there then the whole file goes for a toss. 2. In the above file, I would definately not like to have “!ruby/object”…can I override that somehow?(ofcourse I can have a layer between YAML and file, which modifies the file to change the file structure/contents to make it YAML compliant). 3. is YAML stable enough? I read about syck…it seems to solve the problem of solving perf issues. Any thought’s on above appraoch? Regards, Jatinder ---
**Author:** ![Jatinder\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e4f/32.png) [@Jatinder\_S](https://www.ruby-forum.com/u/Jatinder_S)\ **Post date:** [June 14, 2006, 9:39pm UTC](https://www.ruby-forum.com/t/using-yaml-as-a-data-dsl/63385/2 "2006-06-14T21:39:06Z")
On Wednesday 14 June 2006 11:26 am, Jatinder S. wrote: > YAML provides a way to persist objects in text format which is I believe > very user friendly, so what I thought is that a user can create a file with > above contents and then use YAML::load method to load above file’s content > in to ruby object. I have an application for a customer that provides them with a system to store product information, photographs, inventory data, etc…, and then to search all of it in a freeform way. Because different records might have different data fields which are important, I gave them a simple interface. Data is entered as a YAML hash. Well, mostly, anyway. To be fair, I am not actually using YAML to parse what is entered, because I don’t want to allow anything other than customer: Corona description: Blinky buttons with a narrow profile and embossed face. type key/value pairs. However, the inspiration came from YAML and my use of YAML for config files. It’s a simple enough format that they can get it right without too much difficulty, and it offers flexibility. That said, if your application is going to be used by more than a small, select group of people, I would be hesitant to actually use YAML in the way that you suggest. Perhaps I am overly paranoid, but I don’t want to leave an application open to Joe ScriptKiddie’s attempts to abuse YAML into doing painful things. If I were going to go in that direction, I’d, at the very least, build a preprocessor of some sort to help make sure the content loaded into YAML fits the expected profile. It would still make me nervous, though. Kirk H. ---
**Author:** ![Jatinder\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e4f/32.png) [@Jatinder\_S](https://www.ruby-forum.com/u/Jatinder_S)\ **Post date:** [June 14, 2006, 9:49pm UTC](https://www.ruby-forum.com/t/using-yaml-as-a-data-dsl/63385/3 "2006-06-14T21:49:47Z")
On 6/14/06, Kirk H. [removed\_email\_address@domain.invalid](mailto:removed_email_address@domain.invalid) wrote: > On Wednesday 14 June 2006 11:26 am, Jatinder S. wrote: > > > YAML provides a way to persist objects in text format which is I believe > > very user friendly, so what I thought is that a user can create a file with > > above contents and then use YAML::load method to load above file’s content > > in to ruby object. I have found that when not using a database with ROR you lose a lot of nice automation provided by ActiveRecord. I have in fact been wondering what I’d have to do to make a datasource that looks like a database to Rails but is in fact just an array. Specifically I’d like to still be able to use scaffolds and other generators. The only suggestion I have seen in this regard is to make MEMORY tables using MySQL, but they don’t seem to support auto-increment fields for some reason so I can’t use them. Any ideas in that regard? ---
**Author:** ![Jatinder\_S](https://www.ruby-forum.com/letter_avatar_proxy/v4/letter/j/a88e4f/32.png) [@Jatinder\_S](https://www.ruby-forum.com/u/Jatinder_S)\ **Post date:** [June 14, 2006, 9:52pm UTC](https://www.ruby-forum.com/t/using-yaml-as-a-data-dsl/63385/4 "2006-06-14T21:52:58Z")
This is probably a non-legit example that will just show my stupidity, but: widget\_1\_2\_3: foo: \<% `frmt c:` %\> Misspelling is intentional, to provide a thin layer of safety in case somebody gets “curious.”