I have database field called name. And i have used user.name in my application. Now I have something like salutation which i wanted to append with the name. So what i basically want is when i am accessing name via user.name it should fetch the value from instance method rather then database field.
def name_with_salutation
"#{salutation} #{name}"
end
So when i am accessing name via user.name it should respond with user.name_with_salutation. I have tried alias_method but it shows stack level too deep because name is getting used in name_with_salutation so it got stuck in infinite process.
I am trying this because i do not want to replace name with name_with_salutation throughout the application. This should not apply when i am assigning values user.name = "abc".
Please let me know, How this will be done.
To overwrite an original Model method, you can write a method with same name, and then use read_attribute(:attr) to represent the original attribute value.
Given name attribute exist, to overwrite #name:
def name
"#{salutation} #{read_attribute(:name)}"
end
Related
I am trying to store the currently logged user into a many2one field using compute method. It's working fine if i define the Mnay2one field without the store="True" parameter. Actually, i need to save it.
Here is the code:
def get_logged_user(self):
for rec in self:
print('inside get_logged_user---------------',rec.env.user.name)
rec.logged_user_id = rec.env.user.id
logged_user_id = fields.Many2one('res.users',string="Logged user",store=True,compute="get_logged_user")
EDIT:
If you only need to control visibility of a field/button inside QWeb view you could archive this without dedicated field. You could use context.get('uid') to get current user like this:
<button ... invisible="context.get('uid') == assigned_user_id">
But if you need to store logged-in user inside a field you could use default instead of compute.
Something like this:
logged_user_id = fields.Many2one('res.users', string="Logged user", default=lambda self: self.env.user)
Note usage of lambda function.
If you really need to use compute field with store=True you need to specify when to compute it. By using api.depends decorator you can trigger it when your_field is changed.
#api.depends('your_field')
def get_logged_user(self):
But I would ask a question why do you need to store logged-in user inside a field? If you could provide more context maybe we could suggest different solution.
I want URL manager to process URL with the company name with my CompanyController. To do so dynamically I should get company names from my database.
Now I have such rule (but it's not dynamic):
'<alias:(vector|karnasch|tecnomagnete|ruko|bds-maschinen|exact)>' => 'company/view',
(vector|karnasch|tecnomagnete|ruko|bds-maschinen|exact) --> data to this line I want to get from database.
I can get this data (manually establish connection to db), but maybe it's another more beautiful solution with help of Yii functional. Thanks!
You can always create your custom UrlRuleclass. If you only want to parse incoming URLs you can simply return false from the createUrl() method. In the parseUrl() method you query the DB for your company names and inspect if the current URL matches. If not, you simply return false again.
Well, you don't need to do this, you just have to define the right pattern, e.g. :
'contact' => 'contact/form',
// other rules should be set before this one
'<alias:[-\w]+>' => 'company/view',
http://www.yiiframework.com/doc/guide/1.1/en/topics.url#using-named-parameters
Let's say you're in your user controller and you want to change the name a #user based on some params you have available to you.
I want to know if there is any difference between the following:
#user.name = params[:user][:name]
or
#user.assign_attributes({:name=> params[:user][:name]})
Thanks in advance!
A great way to figure out questions like this is to dive into the source. I found the method in activerecord/lib/active_record/attribute_assignment.rbCheck it out here.
The assign_attributes method will actually just loop through the parameters given and sends the :name= message to your model. However, because you are possibly assigning many attributes, it takes into account mass-assignment precautions. (ie. make sure that the attribute is listed as attr_accessible).
The = (e.g. #user.name = params[:user][:name]) directly calls the attribute setter with no security check. The assign_attributes checks security for the values passed in.
From the Rails API for assign_attributes:
Allows you to set all the attributes for a particular mass-assignment
security role by passing in a hash of attributes with keys matching
the attribute names (which again matches the column names) and the
role name using the :as option.
Source for assign_attributes
First, some background:
I have a Company model, a Project model and a Task model. A Project belongs to a company and a Task belongs_to a Project.
The Project model holds several attributes: company_id, date. These attributes uniquely identify a project
I am letting the users create a task by API by POSTing to a URL that contains the details necessary to identify the Project. For example:
POST /projects/<comnpany_name>/<date>/tasks/
In order to make life easier for the users, in case there is no project with the given details, I'd like to create the project on the fly by the given details, and then to create the task and assign it to the project.
...And my problem is:
When there is a problem to create the project, let's say that the company name is not valid, what is the right way to return the error message and communicate to the user?
I'll explain what I mean: I added a create_by_name_and_company_name method to the Project:
def self.create_by_name_and_company_name(name, company_name)
if company = Company.find_by_name(company_name)
project = Project.create(company_id: company.id,
name: name)
else # cannot create this project, trying to communicate the error
project = Project.new(name: name)
project.errors.add(:company, 'must have a valid name')
end
company
end
I was hoping that by returning an unsaved Company object, with errors set, will be a good way communicate the error (This is similar to how rails work when there's a validation error).
The problem is that when calling valid? on the company object, it removed the error I wrote there and adds the regular validation errors (in this case, company can't be blank).
And a bonus question...
And there is a conceptual problem as well: since I'm creating a model by providing parameters that are being used to create the actual attributes, they doesn't always map nicely to the errors[:attr] hash. In this case it is not so bad and I'm using the company field for the company name parameter, but I guess this can get messier when the parameters provided to the create method are less similar to the model attributes.
So what is the preferred approach to tackle that problem? Is there something basically wrong with that approach? if so, what is the preferred approach?
About overriding the default rails validation error message, you need to write your validation constraint like this:
validates_presence_of :name, :message => "must be a valid name"
I figure that it is best to avoid such nesting and stick to a shallower API.
I have a big, flat table:
id
product_id
attribute1
attribute2
attribute3
attribute4
Here is how I want users to get to products:
See a list of unique values for attribute1.
Clicking one of those gets you a list of unique values for attribute2.
Clicking one of those gets you a list of unique values for attribute3.
Clicking one of those gets you a list of unique values for attribute4.
Clicking one of those shows you the relevant products.
I have been coding Rails for about 4 years now. I just can't unthink my current approach to this problem.
I have major writer's block. Seems like such an easy problem. But I either code it with 4 different "step" methods in my controller, or I try to write one "search" method that attempts to divine the last level you selected, and all the previous values that you selected.
Both are major YUCK and I keep deleting my work.
What is the most elegant way to do this?
Here is a solution that may be an option. Just off the top of my head and not tested (so there is probably a bit more elegant solution). You could use chained scopes in your model:
class Product < ActiveRecord::Base
scope :with_capacity, lambda { |*args| args.first.nil? ? nil : where(:capacity=>args.first) }
scope :with_weight, lambda { |*args| args.first.nil? ? nil : where(:weight=>args.first) }
scope :with_color, lambda { |*args| args.first.nil? ? nil : where(:color=>args.first) }
scope :with_manufacturer, lambda { |*args| args.first.nil? ? nil : where(:manufacturer=>args.first) }
self.available_attributes(products,attribute)
products.collect{|product| product.send(attribute)}.uniq
end
end
The code above will give you a scope for each attribute. If you pass a parameter to the scope, then it will give you the products with that attribute value. If the argument is nil, then the scope will return the full set (I think ;-). You could keep track of the attributes they are drilling down in in the session with 2 variables (page_attribute and page_attribute_value) in your controller. Then you call the entire chain to get your list of products (if you want to use them on the page). Next you can get the attribute values by passing in the set of products and the attribute name to Product.available_attributes. Note that this method (Product.available_attributes) is a total hack and would be inefficient for a large set of data, so you may want to make this another scope and use :select=>"DISTINCT(your_attribute)" or something more database efficient instead of iterating thru the full set of products as I did in the hack method.
class ProductsController < ApplicationController
def show
session[params[:page_attribute].to_sym] = params[:page_attribute_value]
#products = Product.all.with_capacity(session[:capacity]).with_weight(session[:weight]).with_color(session[:color]).with_manufacturer(session[:manufacturer])
#attr_values = Product.available_attributes(#products,params[:page_attribute])
end
end
Again, I want to warn you that I did not test this code, so its totally possible that some of the syntax is incorrect, but hopefully this will give you a starting point. Holla if you have any questions about my (psuedo) code.