AJAX autocomplete based on a static table in the database

Rails
1

I have a field where a user enters his city. I want to add
autocompletion to this field based on a table with a predefined set of
cities not based on previous entries of other users. How can I do this?

I know about the method described in rails recipes which allows to
cache a predefined set of values for autocompletion
(Autocomplete.Local). This is not what I’m looking for though because
my list of cities is very long and I don’t want to cache it.

Thanks,
Aeneas

2

On 9/22/06, Aeneas [email protected] wrote:

I have a field where a user enters his city. I want to add
autocompletion to this field based on a table with a predefined set of
cities not based on previous entries of other users. How can I do this?

I know about the method described in rails recipes which allows to
cache a predefined set of values for autocompletion
(Autocomplete.Local). This is not what I’m looking for though because
my list of cities is very long and I don’t want to cache it.

You can write your own “auto_complete_for_#{object}_#{method}” method
pretty easily, rather than calling auto_complete_for to generate it
for you. The source code of auto_complete_for is a good starting
point.

– James

3

Thanks James. I solved the problem now. It’s really easy. In your
controller you just replace

auto_complete_for :ad, :city

with

def auto_complete_for_ad_city
@cities = City.find(:all)
render :inline => “<%= auto_complete_result(@cities, ‘name’) %>”
end

For this to work you will need a table called cities and a city model.

Aeneas

4

I still have one probelm though. The soruce for auto_complete_for is as
follows:

37: def auto_complete_for(object, method, options = {})
38: define_method(“auto_complete_for_#{object}_#{method}”) do
39: find_options = {
40: :conditions => [ “LOWER(#{method}) LIKE ?”, ‘%’ +
params[object][method].downcase + ‘%’ ],
41: :order => “#{method} ASC”,
42: :limit => 10 }.merge!(options)
43:
44: @items = object.to_s.camelize.constantize.find(:all,
find_options)
45:
46: render :inline => “<%= auto_complete_result @items,
‘#{method}’ %>”
47: end
48: end

However, the following adaption dowsn’t work (in the controller):

def auto_complete_for_ad_city
@items = City.to_s.camelize.constantize.find( :all,
:conditions => [ “LOWER(name) LIKE ?”, ‘%’ +
params[ad][city].downcase + ‘%’ ],
:order => “name ASC”,
:limit => 10
)
render :inline => “<%= auto_complete_result(@items, ‘name’)
%>”
end

the part causing problems is params[city][name]. Is this really the
variable which stores the letters typed into the field ad[city]? The
error message is: undefined local variable or method `ad’ for
#AdsController:0xb79908c0

Any ideas?

Aeneas

5

I still have one probelm though. The soruce for auto_complete_for is as
follows:

37: def auto_complete_for(object, method, options = {})
38: define_method(“auto_complete_for_#{object}_#{method}”) do
39: find_options = {
40: :conditions => [ “LOWER(#{method}) LIKE ?”, ‘%’ +
params[object][method].downcase + ‘%’ ],
41: :order => “#{method} ASC”,
42: :limit => 10 }.merge!(options)
43:
44: @items = object.to_s.camelize.constantize.find(:all,
find_options)
45:
46: render :inline => “<%= auto_complete_result @items,
‘#{method}’ %>”
47: end
48: end

However, the following adaption dowsn’t work (in the controller):

def auto_complete_for_ad_city
@items = City.to_s.camelize.constantize.find( :all,
:conditions => [ “LOWER(name) LIKE ?”, ‘%’ +
params[ad][city].downcase + ‘%’ ],
:order => “name ASC”,
:limit => 10
)
render :inline => “<%= auto_complete_result(@items, ‘name’)
%>”
end

the part causing problems is params[city][name]. Is this really the
variable which stores the letters typed into the field ad[city]? The
error message is: undefined local variable or method `ad’ for
#AdsController:0xb79908c0

Any ideas?

Aeneas

6

JDL wrote:

41: :order => “#{method} ASC”,
However, the following adaption dowsn’t work (in the controller):
end
params[:ad][:city]

If that’s not where your trouble lies, look at your development log
file. Every param is logged there, so you should be able to see the
names being used.

– James

Thanks, that was it!

So for the archive here the working version:

def auto_complete_for_ad_city
@items = City.to_s.camelize.constantize.find( :all,
:conditions => [ “LOWER(name) LIKE ?”, ‘%’ +
params[:ad][:city].downcase + ‘%’ ],
:order => “name ASC”,
:limit => 10
)
render :inline => “<%= auto_complete_result(@items, ‘name’) %>”
end

7

On 9/22/06, Aeneas [email protected] wrote:

42: :limit => 10 }.merge!(options)

the part causing problems is params[city][name]. Is this really the
variable which stores the letters typed into the field ad[city]? The
error message is: undefined local variable or method `ad’ for
#AdsController:0xb79908c0

Any ideas?

Did you really mean this instead?

params[:ad][:city]

If that’s not where your trouble lies, look at your development log
file. Every param is logged there, so you should be able to see the
names being used.

– James