I'm new to Ruby and to Rails. I have played a bit with Sinatra but I think that Rails is a more complete framework for my project. However, I am running into trouble with this.
I am working with an fairly substantial existing, and heavily used, mySQL database and I am trying to build an API for this that will report on certain features. The features that are needed are, for the most part, counts of records by certain groupings, then drilling down into details.
For example we have a table - tableA, that contains lots of information relating to documentation. One piece of information we want to report on from that is the number of items in a given language. The language code is stored against each item and based on a get request I would like to return JSON.
Request: /languages/:code/count/:tablename
There are two variables in that most specific URL - the code we are counting and the table we are counting from.
I understand that in routes.rb I can set up a mapping:
get '/languages/:code/count/:table', :controller=>'languages', :action=>'count'
I have a controller - languages_controller.rb with a count method in it. this then matches to a corresponding view file count.html.erb
In all the tutorials I have read and examples I have followed the main point seems that 'languages' would be a table in the database and would therefore be available under the 'magic' Rails approach.
My issue is that it is not a table, rather the results of the call should be a limited subset of the fields in tableA. Such as languagecode and count(id).
The description of the language needs to be looked up 'manually' as it is stored as an internal code that is not in a database anywhere (historic decision/madness).
The questions:
how do I have a model that is only a subset of fields, plus some that are manually populated - languagecode, isocode, description, count
Am I right in thinking that once I have the model defined as such as I could use ActiveRecord to get data from the database and then in the controller add the extra information in?
Can I change table in the model based on the parameter sent in the URL?
Essentially, I am at a loss at the moment on what to do with this. I have the routes defined, the view templates in place and the controller there and ready to go. The database component - getting some data from a pre-existing table seems mysterious to me.
Any help is greatly appreciated, it seems that the framework is currently getting in my way and I know that I can't be the only one trying this sort of thing so if you have any advice please share.
There's really no need for a model here, at all. This isn't what ORMs are for. What you should be doing is just running raw SQL against the database, and iterating over the results. Consider doing something like this: https://stackoverflow.com/a/14840547/229044
Related
For a blog model I'm saving an RSS field as text under Blog.rss, problem is, some of this is rather long and each one prints when I'm working in the rails console, ie: Blog.last(10).
Is there a way to hide output unless I call someblog.rss specifically?
I had a similar problem and received some solutions in another forum, which were:
Use select to get just the columns you need
If you have a very long column (I had JSON data structure from a webhook cluttering the console), consider whether you really need it, and if you don't , don't store it in the table
Or, consider storing it in an associated table
if you need the whole object but just want to change how it's represented in console/log output, you can redefine inspect
yourobject.as_json(except: :unwanted_column)
Also
You could look into: https://github.com/awesome-print/awesome_print
I have a datetime value which comes from the API in this format: 2015-07-07T17:30:00+00:00. I simply want to split it up between the date and time values at this point. I am not using an Active Record model and I prefer not to use an sql database if I can.
The way I have set up the app means that the value is "stored" like this in my view: #search.dining_date_and_time
I have tried two approaches to solving this problem:
Manually based on this previous stackoverflow question from 2012: Using multiple input fields for one attribute - but the error I get is the attribute is "nil" even though I put a "try"
Using this gem, https://github.com/ccallebs/split_date_time which is a bit more recent and seems to be a more elegant solution, but after closely following the doc, I get this error, saying my Search model is not initalized and there is no method: undefined method dining_date' for #<Search not initialized>
This is when instead I put #search.dining_date in the view, which seems to be the equivalent of the doc's example (its not that clear). The doc also says the method will be automatically generated.
Do I need to alter my model so I receive the data from the API in another way? ie. not get the variable back as #search.dining_date_and_time from the Search model for any of this to work?
Do I need an Active Record model so that before_filter or before_save logic works - so i can (re)concatenate after splitting so the data is sent back to the API in a format it understands. Can I avoid this - it seems a bit of overkill to restructure the whole app and put in a full database just so I can split and join date/time as needed.
Happy to provide further details, code snippets if required.
As I am not using a conventional Rails DB like MySql Lite or Postgresql, I found that the best solution to the problem was by using this jQuery date Format plugin: https://github.com/phstc/jquery-dateFormat to split the date and time values for display when I get the data back from the API.
The Github docs were not too expansive, but once I put the simply put the library file in my Rails javascript assets folder, I just had to write a few lines of jQuery to get the result and format I wanted:
$(function() {
var rawDateTime = $('#searchDiningDateTime').html();
// console.log(rawDateTime);
var cleanDate = $.format.date(rawDateTime, "ddd, dd/MM/yyyy");
// console.log(cleanDate);
$('#searchDiningDateTime').html(cleanDate);
var cleanTime = $.format.date(rawDateTime, "HH:mm");
// console.log(cleanTime);
$('#searchTime').html(cleanTime);
});
Next challenge: rejoin the values on submit, so the API can read the data by sending/receiving a valid request/response. (The values can't be split like this when sent to the remote service).
What's the best way to do joins in Meteor/mongo? Use one of these packages, or something else:
publish-with-relations
https://github.com/erundook/meteor-publish-with-relations/blob/master/publish_with_relations.coffee
collection-helpers
https://github.com/dburles/meteor-collection-helpers
I'm very familiar with PWR, but collection-helpers is new to me. It looks like the two are complimentary.
PWR solves the somewhat complex problem of publishing documents to the client via a reactive join based on arbitrarily complex relationships. See this question for more details.
collection-helpers appears to be a set of convenience functions added to the client to be used when traversing collection relationships inside of a template (given that the required documents have already been published). For example, if you have books and authors in separate (but related) collections, you can immediately get myBook.author.fullName inside of a template without having to type out the extra find for the author.
currently the top popular solution in atmosphere seems to be publish-composite https://atmospherejs.com/reywood/publish-composite
I am using propel orm as database abstraction layer.
I want to define different schema.xml files for diffenrent modules.
E.g. user.xml.schema for handling users and roles, or app.schema.xml for the application model.
My problem is, I want to reference to the user table of the user.schema.xml. I can handle this by the tag, but I want to use another table prefix for the user schema tables.
Running propel-gen creates two sql files (one for the user.schema and one for the app.schema), but the problem is, that the user-schema tables are generated twice. First with correct table prefix of the user schema file and the others with the prefix of the app schema file.
The foreign key also references to the wrong tables (that from the table with the prefix of the app.schema.xml).
I do not know any way to prevent this behaviour.
Any hints?
You cannot add different table prefixes to one database, and there is no way to add a tablePrefix attribute on the table tag. Let me explain a bit more, I know, you can specify a tablePrefix per XML schema even for a same database, but it leads to errors if you try to add relationship.. I don't know whether it's a bug or not, AFAIK the tablePrefix should be defined at the table level… Without relationship, you'll get a clean SQL file (or two if you don't set the propel.packageObjectModel build property to true.
You can read: http://www.propelorm.org/reference/schema.html. So I think, it's not possible to do what you would like to do unfortunately.
BTW, what you want to achieve is called multi component data model in the Propel doc.
I am wanting to create an application that can allow users to add products for sale.
I want to make it so that a user can add whatever type of product he/she likes and let them also create stored and searchable attributes for their products - alot like google base does.
Does anyone know of the best way to do this ie model it.
I don't really want a table for each category as this would be possibly 1000s of tables.
What is the best way to do this? has anyone got good / bad experiences of this?
Is there any plugins that does this?
Any help would be great
thanks
rick
It sounds like what you want is a tag system.
If you want something more flexible you might want to look at using a document store instead of a database, for example CouchDB.
If you don't want to keep this in a relational database I'd suggest creating a Model called "Descriptor" that would contain the ID of the item being added, the name of the attribute "Color" and the value "Red".
To help keeps things consistent you could also structure pre-set groups of descriptors (for cars: make, model, color) as well as provide auto-completes for the value entry text fields.