Ezra Zygmuntowicz
2005-Dec-01 17:31 UTC
[Solution] Dynamic Where clause for :conditions in AR::Base.find
I have come up with a nice little solution for building the Where
clause dynamically for the : conditions part of a find method in your
models. You can put this wherever you like and require it or you can
put it inside your model class that will use it.
Here it is:
class Where
# Utility class to dynamically create the where clause
# for a rails find method. Initialize expects a nested
# array like: [[:project, 3], [:month, 7], [:user, 0]]
# where each nested array contains a symbol of the column
# name and a value to query for. Lets say that you have
# this hash in your +params+ :
# params = { :person => {:name => "dave" :city =>
"Yakima"}}
# You can use this class to build the where clause like so:
# where = Where.new([ [:user, params[:person][:name]], [:city,
params[:person][:city]] ])
# MyModel.find(:all, :conditions => where.build_where_clause)
def initialize(options=[])
@opts = options
@opts.each do |pair|
instance_variable_set("@#{pair[0].to_sym}", pair[1])
end
end
def build_where_clause
q = []
ary = []
@opts.each do |pair|
iv = instance_variable_get("@#{pair[0]}")
unless iv.nil? || iv.to_s == ''''
q << "#{pair[0]} = ?"
ary << iv
end
end
return [q.join(" and ")].concat(ary)
end
end # End Where
# Some examples:
a = Where.new([[:project, 3], [:month, 7], [:user, 0]])
p a.build_where_clause
# => ["project = ? and month = ? and user = ?", 3, 7, 0]
b = Where.new([[:post, 6], [:user, "admin"], [:comment, 12]])
p b.build_where_clause
# => ["post = ? and user = ? and comment = ?", 6,
"admin", 12]
# built from params. You can see that the params[:person][:state] is
empty.
# this class will take that into consideration and leave that part
out of the where clause
params = {:id => 17, :person => {:city => "Yakima", :name
=>
"dave", :state => ""}}
c = Where.new([[:user, params[:person][:name]], [:city, params
[:person][:city]], [:state, params[:person][:state]]])
p c.build_where_clause
# => ["user = ? and city = ?", "dave",
"Yakima"]
Hope its useful to someone out there!
Cheers-
-Ezra Zygmuntowicz
Yakima Herald-Republic
WebMaster
http://yakimaherald.com
509-577-7732
ezra-gdxLOakOTQ9oetBuM9ipNAC/G2K4zDHf@public.gmane.org
Christer Nilsson
2005-Dec-01 17:53 UTC
Re: Dynamic Where clause for :conditions in AR::Base.find
Nice job, Ezra! Please also show how the following clauses are implemented: name LIKE ''chr%'' number LIKE ''%123'' recipe LIKE ''%butter%'' date <= ''2005-12-01'' Christer -- Posted via http://www.ruby-forum.com/.
Ezra Zygmuntowicz
2005-Dec-01 18:51 UTC
Re: Re: Dynamic Where clause for :conditions in AR::Base.find
On Dec 1, 2005, at 9:53 AM, Christer Nilsson wrote:> Nice job, Ezra! > > Please also show how the following clauses are implemented: > > name LIKE ''chr%'' > number LIKE ''%123'' > recipe LIKE ''%butter%'' > date <= ''2005-12-01'' > > ChristerHrmm.. Good idea! I will flesh out this class to be more flexible and support more variations on the where clause part. How about posting me a list of all the different things you would like to see supported the most? Thanks- -Ezra Zygmuntowicz Yakima Herald-Republic WebMaster http://yakimaherald.com 509-577-7732 ezra-gdxLOakOTQ9oetBuM9ipNAC/G2K4zDHf@public.gmane.org
Christer Nilsson
2005-Dec-01 19:34 UTC
Re: Re: Dynamic Where clause for :conditions in AR::Base.fin
This is a copy of a more elaborate comment: In the same WHERE clause it should be possible to mix the operators: WHERE name LIKE ''chr%'' AND city LIKE ''%FURT'' AND skills LIKE ''%plumbing%'' AND date <= ''2006-12-01'' AND age >= 25 AND age <= 50 AND sex = ''female'' And remember, all 2^7 = 128 combinations should be possible! If age and sex are uninteresting, collapse to: WHERE name LIKE ''chr%'' AND city LIKE ''%FURT'' AND skills LIKE ''%plumbing%'' AND date <= ''2006-12-01'' How can this be specified in a readable form? My long term goal is to NEVER see SQL. This is one of the problems on the journey. Christer -- Posted via http://www.ruby-forum.com/.
David Mitchell
2005-Dec-01 19:42 UTC
Re: Re: Dynamic Where clause for :conditions in AR::Base.find
How about: value IN (select ...) I''m finding myself using that more and more often lately... Regards Dave M. On 12/2/05, Ezra Zygmuntowicz <ezra-SD1UcFUIF7QjH4SCZfkgnw@public.gmane.org> wrote:> > On Dec 1, 2005, at 9:53 AM, Christer Nilsson wrote: > > > Nice job, Ezra! > > > > Please also show how the following clauses are implemented: > > > > name LIKE ''chr%'' > > number LIKE ''%123'' > > recipe LIKE ''%butter%'' > > date <= ''2005-12-01'' > > > > Christer > > > Hrmm.. Good idea! I will flesh out this class to be more flexible and > support more variations on the where clause part. How about posting > me a list of all the different things you would like to see supported > the most? > > Thanks- > > -Ezra Zygmuntowicz > Yakima Herald-Republic > WebMaster > http://yakimaherald.com > 509-577-7732 > ezra-gdxLOakOTQ9oetBuM9ipNAC/G2K4zDHf@public.gmane.org > > > > _______________________________________________ > Rails mailing list > Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org > http://lists.rubyonrails.org/mailman/listinfo/rails >
Hammed Malik
2005-Dec-02 00:31 UTC
Re: Re: Dynamic Where clause for :conditions in AR::Base.find
since you asked... please consider adding BETWEEN date1 AND date2 A good search filter plugin would be extremely useful. On 01/12/05, David Mitchell <monch1962-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:> > How about: > value IN (select ...) > > I''m finding myself using that more and more often lately... > > Regards > > Dave M. > > On 12/2/05, Ezra Zygmuntowicz <ezra-SD1UcFUIF7QjH4SCZfkgnw@public.gmane.org> wrote: > > > > On Dec 1, 2005, at 9:53 AM, Christer Nilsson wrote: > > > > > Nice job, Ezra! > > > > > > Please also show how the following clauses are implemented: > > > > > > name LIKE ''chr%'' > > > number LIKE ''%123'' > > > recipe LIKE ''%butter%'' > > > date <= ''2005-12-01'' > > > > > > Christer > > > > > > Hrmm.. Good idea! I will flesh out this class to be more flexible and > > support more variations on the where clause part. How about posting > > me a list of all the different things you would like to see supported > > the most? > > > > Thanks- > > > > -Ezra Zygmuntowicz > > Yakima Herald-Republic > > WebMaster > > http://yakimaherald.com > > 509-577-7732 > > ezra-gdxLOakOTQ9oetBuM9ipNAC/G2K4zDHf@public.gmane.org > > > > > > > > _______________________________________________ > > Rails mailing list > > Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > _______________________________________________ > Rails mailing list > Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org > http://lists.rubyonrails.org/mailman/listinfo/rails >_______________________________________________ Rails mailing list Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org http://lists.rubyonrails.org/mailman/listinfo/rails
In respone to all the wishes for an extension of Ezra''s original class, I created the "where" plugin Here''s the description as it is on the Wiki: An easier way to create where clauses. Creates a class for easily building the where clauses for the Model.find(..., :conditions => condition ) where = InVisible::Where.new( [[ :first, "Jens-Christian"], [ :last, "Fischer" ] ] ) where.add( [ [ :age, :gt, 30 ] ] ) where.add( [ [ :city, :like, "Zur%" ] ] ) Adress.find( :all, :condition => where.build_where_clause ) This is based on the Where class, that Ezra Zygmuntowic sent to the rails mailing list on 2005-12-01 and includes all the wishes that came. The following is understood: [ :age, 34 ] => “age = ?” [ :age, :eq, 34 ] => “age = ?” [ :age, :gt, 34 ] => “age > ?” [ :age, :lt, 34 ] => “age < ?” [ :age, :gteq, 34 ] => “age => ?” [ :age, :lteq, 34 ] => “age <= ?” [ :name, :like, “abc%” ] => “name LIKE ?” [ :date, :between, date1, date2 ] => “date BETWEEN ? and ?” [ :ip, [:gt, :inet], “12.34.56.78/24” ] => “ip > inet ?” (let’s you type the value (for example the inet type in Postgres) [ :sql, “hosts.id = logs.host_id and hosts.name”, :like, “123.23.45.67”] => “hosts.id = logs.host_id and hosts.name LIKE ? (for those time when you really need SQL. Use any symbol that starts with” (so you can have multiple SQL additions) There also is an extension to ActiveRecord::Base that allows you to get the SQL query that AR will create. Use like this: Model.get_sql( :all, :conditions =>..., :limit => ..., ) with the same parameters as the Model.find() method. Does not honor the :include option svn: http://invisible.ch/svn/projects/plugins/where Have fun playing with it Jens-Christian -- InVisible GmbH, Langgrütstrasse 172, 8047 Zürich Phone: +41 44 401 09 30 http://www.invisible.ch http://not.invisible.ch _______________________________________________ Rails mailing list Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org http://lists.rubyonrails.org/mailman/listinfo/rails
Why is this better than SQL? On 12/13/05, Jens-Christian Fischer <jcf-m2zzWtmgR3gXXHkOk0aIfQ@public.gmane.org> wrote:> In respone to all the wishes for an extension of Ezra''s original > class, I created the "where" plugin > > Here''s the description as it is on the Wiki: > > An easier way to create where clauses. > > Creates a class for easily building the where clauses for the > Model.find(..., :conditions => condition ) > > where = InVisible::Where.new( [[ :first, "Jens-Christian"], [ :last, > "Fischer" ] ] ) > where.add( [ [ :age, :gt, 30 ] ] ) > where.add( [ [ :city, :like, "Zur%" ] ] ) > > Adress.find( :all, :condition => where.build_where_clause ) > > > This is based on the Where class, that Ezra Zygmuntowic sent to the > rails mailing list on 2005-12-01 and includes all the wishes that > came. The following is understood: > [ :age, 34 ] => "age = ?" > [ :age, :eq, 34 ] => "age = ?" > [ :age, :gt, 34 ] => "age > ?" > [ :age, :lt, 34 ] => "age < ?" > [ :age, :gteq, 34 ] => "age => ?" > [ :age, :lteq, 34 ] => "age <= ?" > [ :name, :like, "abc%" ] => "name LIKE ?" > [ :date, :between, date1, date2 ] => "date BETWEEN ? and ?" > [ :ip, [:gt, :inet], "12.34.56.78/24" ] => "ip > inet ?" (let''s you > type the value (for example the inet type in Postgres) > [ :sql, "hosts.id = logs.host_id and hosts.name", :like, > "123.23.45.67"] => "hosts.id = logs.host_id and hosts.name LIKE ? > (for those time when you really need SQL. Use any symbol that starts > with" (so you can have multiple SQL additions) > There also is an extension to ActiveRecord::Base that allows you to > get the SQL query that AR will create. Use like this: > > Model.get_sql( :all, :conditions =>..., :limit => ..., ) with the > same parameters as the Model.find() method. Does not honor > the :include option > > svn: http://invisible.ch/svn/projects/plugins/where > > Have fun playing with it > > Jens-Christian > > -- > InVisible GmbH, Langgrütstrasse 172, 8047 Zürich > Phone: +41 44 401 09 30 > http://www.invisible.ch http://not.invisible.ch > > > > _______________________________________________ > Rails mailing list > Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org > http://lists.rubyonrails.org/mailman/listinfo/rails > > > >
Am 13.12.2005 um 18:36 schrieb Kyle Maxwell:> Why is this better than SQL?I have a controller with a form that filters are rather large data- set. Different parameters need different treatment (like the "inet" datatype). Building the SQL string manually is certainly doable, but a bit of a mess. Using the "Where" Class, make imo for an easier to read controller method. And for easy forms you can more or less just use the params hash (as Ezra showed in his original example) cu jc -- InVisible GmbH, Langgrütstrasse 172, 8047 Zürich Phone: +41 44 401 09 30 http://www.invisible.ch http://not.invisible.ch _______________________________________________ Rails mailing list Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org http://lists.rubyonrails.org/mailman/listinfo/rails
Hello This plugin seems to be just what I''ve been looking for. I''m currently working on my first real rails project and the problem I''m having is bound to be very trivial. I would like to have a search form that contains lots of options like:- Name of Provider Min Price Max Price Type of Accommodation Location (Zip Code / Postcode) The user should be able to optionally select any of the various criteria. If they entered the name of the provider the query would use a %like% condition. Also, if the user entered both the min and the max price the between condition would be used. Whereas if the user entered just the max price the less than SQL operator would be used. I''m not entirely sure how to actually build the Where clause. Is it possible to pass in the params hash or do you have to build the where clause in the controller? I''m just having problems working out what code would be in the form and what would be in the controller. Any sample code would be greatly appreciated! Thanks in advance. Regards Harvey On 13/12/05 19:36, "Jens-Christian Fischer" <jcf-m2zzWtmgR3gXXHkOk0aIfQ@public.gmane.org> wrote:> Am 13.12.2005 um 18:36 schrieb Kyle Maxwell: > >> Why is this better than SQL? > > I have a controller with a form that filters are rather large data- > set. Different parameters need different treatment (like the "inet" > datatype). Building the SQL string manually is certainly doable, but > a bit of a mess. Using the "Where" Class, make imo for an easier to > read controller method. > > And for easy forms you can more or less just use the params hash (as > Ezra showed in his original example)Thanks in advance Harvey This e-mail has been scanned for all viruses by MessageLabs.
> Creates a class for easily building the where clauses for the > Model.find(..., :conditions => condition ) > > where = InVisible::Where.new( [[ :first, "Jens-Christian"], [ :last, > "Fischer" ] ] ) > where.add( [ [ :age, :gt, 30 ] ] ) > where.add( [ [ :city, :like, "Zur%" ] ] ) > > Adress.find( :all, :condition => where.build_where_clause )I''m not crazy about that API at all. Why not hide all that from me and let me do: Model.find_with_conditions(:all, :order => ....) do |where| where << [:age, :gt, 30] where << [:city, :like, "Zur%"] end That way the instantiation of the Where class is invisible to the coder and could even be swapped out with a different class if desired. -- rick http://techno-weenie.net
If you like to write it like this you can still make conditions out of
it in one single line of ruby:
c = [ [ :age, ''='', 30 ],
[ :city, ''LIKE'', "Zur%" ] ]
conditions = c.collect { |k,r,v| "#{k} #{r} #{v}"}.join('' AND
'')
On 12/13/05, Jens-Christian Fischer
<jcf-m2zzWtmgR3gXXHkOk0aIfQ@public.gmane.org>
wrote:> In respone to all the wishes for an extension of Ezra''s original
> class, I created the "where" plugin
>
> Here''s the description as it is on the Wiki:
>
> An easier way to create where clauses.
>
> Creates a class for easily building the where clauses for the
> Model.find(..., :conditions => condition )
>
> where = InVisible::Where.new( [[ :first, "Jens-Christian"], [
:last,
> "Fischer" ] ] )
> where.add( [ [ :age, :gt, 30 ] ] )
> where.add( [ [ :city, :like, "Zur%" ] ] )
>
> Adress.find( :all, :condition => where.build_where_clause )
>
>
> This is based on the Where class, that Ezra Zygmuntowic sent to the
> rails mailing list on 2005-12-01 and includes all the wishes that
> came. The following is understood:
> [ :age, 34 ] => "age = ?"
> [ :age, :eq, 34 ] => "age = ?"
> [ :age, :gt, 34 ] => "age > ?"
> [ :age, :lt, 34 ] => "age < ?"
> [ :age, :gteq, 34 ] => "age => ?"
> [ :age, :lteq, 34 ] => "age <= ?"
> [ :name, :like, "abc%" ] => "name LIKE ?"
> [ :date, :between, date1, date2 ] => "date BETWEEN ? and ?"
> [ :ip, [:gt, :inet], "12.34.56.78/24" ] => "ip > inet
?" (let''s you
> type the value (for example the inet type in Postgres)
> [ :sql, "hosts.id = logs.host_id and hosts.name", :like,
> "123.23.45.67"] => "hosts.id = logs.host_id and
hosts.name LIKE ?
> (for those time when you really need SQL. Use any symbol that starts
> with" (so you can have multiple SQL additions)
> There also is an extension to ActiveRecord::Base that allows you to
> get the SQL query that AR will create. Use like this:
>
> Model.get_sql( :all, :conditions =>..., :limit => ..., ) with the
> same parameters as the Model.find() method. Does not honor
> the :include option
>
> svn: http://invisible.ch/svn/projects/plugins/where
>
> Have fun playing with it
>
> Jens-Christian
>
> --
> InVisible GmbH, Langgrütstrasse 172, 8047 Zürich
> Phone: +41 44 401 09 30
> http://www.invisible.ch http://not.invisible.ch
>
>
>
> _______________________________________________
> Rails mailing list
> Rails-1W37MKcQCpIf0INCOvqR/iCwEArCW2h5@public.gmane.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>
>
>
--
Tobi
http://jadedpixel.com - modern e-commerce software
http://typo.leetsoft.com - Open source weblog engine
http://blog.leetsoft.com - Technical weblog
> I''m not crazy about that API at all. Why not hide all that from me > and let me do: > > Model.find_with_conditions(:all, :order => ....) do |where| > where << [:age, :gt, 30] > where << [:city, :like, "Zur%"] > endI just updated the plugin to allow for this case. ( And I dropped the requirement for the :gt, :lt etc symbols (just use ''<'', ''>'', etc.) ) happy new year jc -- InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich Phone: +41 44 401 09 30 http://www.invisible.ch http://not.invisible.ch -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2361 bytes Desc: not available Url : http://wrath.rubyonrails.org/pipermail/rails/attachments/20060101/0b253095/smime.bin
Happy new Year Jens-Christian, I am considering this a new years gift.... That was quick... Thanks Rick for the idea.... l On 12/31/05, Jens-Christian Fischer <jcf@invisible.ch> wrote:> > > I''m not crazy about that API at all. Why not hide all that from me > > and let me do: > > > > Model.find_with_conditions(:all, :order => ....) do |where| > > where << [:age, :gt, 30] > > where << [:city, :like, "Zur%"] > > end > > I just updated the plugin to allow for this case. ( And I dropped the > requirement for the :gt, :lt etc symbols (just use ''<'', ''>'', etc.) ) > > happy new year > jc > > > -- > InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich > Phone: +41 44 401 09 30 > http://www.invisible.ch http://not.invisible.ch > > > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/rails > > > >-- First they laugh at you, then they ignore you, then they fight you. Then you win. -- Mahatma Karamchand Gandhi -------------- next part -------------- An HTML attachment was scrubbed... URL: http://wrath.rubyonrails.org/pipermail/rails/attachments/20060101/647d23f5/attachment.html
When i use pagination it is still ugly.> where = InVisible::Where.new( [[ :first, "Jens-Christian"], [ :last, > "Fischer" ] ] ) > where.add( [ [ :age, :gt, 30 ] ] ) > where.add( [ [ :city, :like, "Zur%" ] ] )@address_pages, @addresses = paginate :address, :conditions => where.build_where_clause, :per_page => 10, :order_by => ''first'' How can I hide and clean up my code when using pagination. l On 1/1/06, Leon Leslie <leonleslie@gmail.com> wrote:> > Happy new Year Jens-Christian, > > I am considering this a new years gift.... That was quick... > > Thanks Rick for the idea.... > > l > > > On 12/31/05, Jens-Christian Fischer <jcf@invisible.ch> wrote: > > > > I''m not crazy about that API at all. Why not hide all that from me > > > and let me do: > > > > > > Model.find_with_conditions(:all, :order => ....) do |where| > > > where << [:age, :gt, 30] > > > where << [:city, :like, "Zur%"] > > > end > > > > I just updated the plugin to allow for this case. ( And I dropped the > > requirement for the :gt, :lt etc symbols (just use ''<'', ''>'', etc.) ) > > > > happy new year > > jc > > > > > > -- > > InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich > > Phone: +41 44 401 09 30 > > http://www.invisible.ch http://not.invisible.ch > > > > > > > > _______________________________________________ > > Rails mailing list > > Rails@lists.rubyonrails.org > > http://lists.rubyonrails.org/mailman/listinfo/rails > > > > > > > > > > > -- > First they laugh at you, then they ignore you, then they fight you. > Then you win. > -- Mahatma Karamchand Gandhi-- First they laugh at you, then they ignore you, then they fight you. Then you win. -- Mahatma Karamchand Gandhi -------------- next part -------------- An HTML attachment was scrubbed... URL: http://wrath.rubyonrails.org/pipermail/rails/attachments/20060101/6ba74d30/attachment.html
When I was originally playing with this I came up with this little
class : http://rubyurl.com/DxL
With that one you can build the conditions with a lightly nicer syntax:
c = Cond.new do
month ''<='', 11
year ''='', 2005
name ''LIKE'', ''ruby%''
end
c.where
# => ["month <= ? and year = ? and name LIKE ?", 11, 2005,
"ruby%"]
@address_pages, @addresses = paginate :address,
:conditions => c.where, :per_page => 10, :order_by =>
''first''
It still is a little verbose compared to just writing it out by hand
but it does abstract things a little bit.
Cheers-
-Ezra
On Jan 1, 2006, at 4:41 AM, Leon Leslie wrote:
> When i use pagination it is still ugly.
>
> > where = InVisible::Where.new( [[ :first, "Jens-Christian"],
[ :last,
> > "Fischer" ] ] )
> > where.add( [ [ :age, :gt, 30 ] ] )
> > where.add( [ [ :city, :like, "Zur%" ] ] )
>
> @address_pages, @addresses = paginate :address,
> :conditions => where.build_where_clause, :per_page =>
> 10, :order_by => ''first''
>
> How can I hide and clean up my code when using pagination.
>
> l
>
>
> On 1/1/06, Leon Leslie <leonleslie@gmail.com > wrote:
> Happy new Year Jens-Christian,
>
> I am considering this a new years gift.... That was quick...
>
> Thanks Rick for the idea....
>
> l
>
>
> On 12/31/05, Jens-Christian Fischer <jcf@invisible.ch> wrote:
> > I''m not crazy about that API at all. Why not hide all that
from me
> > and let me do:
> >
> > Model.find_with_conditions(:all, :order => ....) do |where|
> > where << [:age, :gt, 30]
> > where << [:city, :like, "Zur%"]
> > end
>
> I just updated the plugin to allow for this case. ( And I dropped the
> requirement for the :gt, :lt etc symbols (just use
''<'', ''>'', etc.) )
>
> happy new year
> jc
>
>
> --
> InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich
> Phone: +41 44 401 09 30
> http://www.invisible.ch http://not.invisible.ch
>
>
>
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
>
>
>
>
>
>
> --
> First they laugh at you, then they ignore you, then they fight you.
> Then you win.
> -- Mahatma Karamchand Gandhi
>
>
>
> --
> First they laugh at you, then they ignore you, then they fight you.
> Then you win.
> -- Mahatma Karamchand Gandhi
> _______________________________________________
> Rails mailing list
> Rails@lists.rubyonrails.org
> http://lists.rubyonrails.org/mailman/listinfo/rails
-Ezra Zygmuntowicz
WebMaster
Yakima Herald-Republic Newspaper
ezra@yakima-herald.com
509-577-7732
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> When I was originally playing with this I came up with this little > class : http://rubyurl.com/DxL > > With that one you can build the conditions with a lightly nicer > syntax: > > c = Cond.new do > month ''<='', 11 > year ''='', 2005 > name ''LIKE'', ''ruby%'' > endAhh - I didn''t realize you already had that class fleshed out. I''m fairly new to methods taking blocks, so I didn''t know how to use your syntax (which I like) with the Model.find_with_conditions .... method. The "method_missing" won''t work, because it would override ActiveRecords method_missing, right? How to integrate those two concepts? jc -- InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich Phone: +41 44 401 09 30 http://www.invisible.ch http://not.invisible.ch -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2361 bytes Desc: not available Url : http://wrath.rubyonrails.org/pipermail/rails/attachments/20060101/9b8b18cc/smime.bin
On Jan 1, 2006, at 2:56 PM, Jens-Christian Fischer wrote:>> When I was originally playing with this I came up with this little >> class : http://rubyurl.com/DxL >> >> With that one you can build the conditions with a lightly nicer >> syntax: >> >> c = Cond.new do >> month ''<='', 11 >> year ''='', 2005 >> name ''LIKE'', ''ruby%'' >> end > > Ahh - I didn''t realize you already had that class fleshed out. I''m > fairly new to methods taking blocks, so I didn''t know how to use > your syntax (which I like) with the > > Model.find_with_conditions .... > > method. The "method_missing" won''t work, because it would override > ActiveRecords method_missing, right? > > How to integrate those two concepts? > > jc > > -- > InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich > Phone: +41 44 401 09 30 > http://www.invisible.ch http://not.invisible.ch > > _______________________________________________ > Rails mailing list > Rails@lists.rubyonrails.org > http://lists.rubyonrails.org/mailman/listinfo/railsI will have to take a look at how you implemented the find_with_conditions and get back to you. It should be possible though. There might be something that could be done with calling super in the method_missing to make sure we don''t entirely override AR''s method_missing. Or maybe the best way would be to keep the method_missing confined in the Cond class and yield a new Cond object when find_with_conditions gets called. I will take a peek and get back to you with a patch. Cheers- -Ezra Zygmuntowicz WebMaster Yakima Herald-Republic Newspaper ezra@yakima-herald.com 509-577-7732
Jens-Christian-
So I played with things a bit to make the Cond class take a block
and make the find_with_conditions pass the block into the Cond.new
statement. Here is the simplified code that if you made some changes
to your Where class you could use the method_missing interface. Its
using my Cond class instead of your Where class for now and a
simplified version of the find_with_conditions just for examples sake:
class Cond
def initialize(&block)
@args = []
instance_eval(&block) if block_given?
end
def method_missing(sym, *args)
@args << [sym,args.flatten].flatten
end
def where(args=@args)
args.each do |triplet|
instance_variable_set("@#{triplet[0].to_sym}", triplet[2])
end
q = []
ary = []
args.each do |triplet|
iv = instance_variable_get("@#{triplet[0]}")
unless iv.nil? || iv.to_s == ''''
q << "#{triplet[0]} #{triplet[1]} ?"
ary << iv
end
end
return [q.join(" and ")].concat(ary)
end
end
class Base
def self.find_with_conditions(*args, &block)
cond = Cond.new(&block)
#code goes here for dealing with the options hash merge and
calling find.
# simplified for examples sake we will just return the where
clause for now
cond.where
end
end
a = Base.find_with_conditions do
month ''<='', 11
year ''='' , "red"
end
p a
#=> ["month <= ? and year = ?", 11, "red"]
So if you make your Where class use an initialize method that takes
a block like my Cond class above does, then you can use the nice
syntax with either find_with_conditions by passing the block into the
constructor like this: Cond.new(&block) or when you just want to
build the where clause by itself like this:
c = Cond.new do
month ''<='', 11
year ''='', 2005
name ''LIKE'', ''ruby%''
end
c.where
# => ["month <= ? and year = ? and name LIKE ?", 11, 2005,
"ruby%"]
Play with that for a bit and see if you like it. I think it will be
the easiest way to get the syntax we like. I will make this a patch
for your where plugin later today unles you would rather do it? Let
me know.
Cheers-
-Ezra Zygmuntowicz
WebMaster
Yakima Herald-Republic Newspaper
ezra@yakima-herald.com
509-577-7732
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Jens-Christian-
So I played with things a bit to make the Cond class take a block and
make the find_with_conditions pass the block into the Cond.new
statement. Here is the simplified code that if you made some changes to
your Where class you could use the method_missing interface. Its using
my Cond class instead of your Where class for now and a simplified
version of the find_with_conditions just for examples sake:
class Cond
def initialize(&block)
@args = []
instance_eval(&block) if block_given?
end
def method_missing(sym, *args)
@args << [sym,args.flatten].flatten
end
def where(args=@args)
args.each do |triplet|
instance_variable_set("@#{triplet[0].to_sym}", triplet[2])
end
q = []
ary = []
args.each do |triplet|
iv = instance_variable_get("@#{triplet[0]}")
unless iv.nil? || iv.to_s == ''''
q << "#{triplet[0]} #{triplet[1]} ?"
ary << iv
end
end
return [q.join(" and ")].concat(ary)
end
end
class Base
def self.find_with_conditions(*args, &block)
cond = Cond.new(&block)
#code goes here for dealing with the options hash merge and calling
find.
# simplified for examples sake we will just return the where clause
for now
cond.where
end
end
a = Base.find_with_conditions do
month ''<='', 11
year ''='' , "red"
end
p a
#=> ["month <= ? and year = ?", 11, "red"]
So if you make your Where class use an initialize method that takes a
block like my Cond class above does, then you can use the nice syntax
with either find_with_conditions by passing the block into the
constructor like this: Cond.new(&block) or when you just want to build
the where clause by itself like this:
c = Cond.new do
month ''<='', 11
year ''='', 2005
name ''LIKE'', ''ruby%''
end
c.where
# => ["month <= ? and year = ? and name LIKE ?", 11, 2005,
"ruby%"]
Play with that for a bit and see if you like it. I think it will be the
easiest way to get the syntax we like. I will make this a patch for your
where plugin later today unles you would rather do it? Let me know.
Cheers-
-Ezra Zygmuntowicz
WebMaster
Yakima Herald-Republic Newspaper
ezra@yakima-herald.com
509-577-7732
--
Posted via http://www.ruby-forum.com/.
> > Play with that for a bit and see if you like it. I think it will > be the > easiest way to get the syntax we like. I will make this a patch for > your > where plugin later today unles you would rather do it? Let me know.Looks good (from skimming over the code). I''m returning from our mountain retreat to the city today, so I likely won''t have time to write that patch. Feel free to do it, I''ll integrate it later then. thanks jc -- InVisible GmbH, Langgr?tstrasse 172, 8047 Z?rich Phone: +41 44 401 09 30 http://www.invisible.ch http://not.invisible.ch -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2361 bytes Desc: not available Url : http://wrath.rubyonrails.org/pipermail/rails/attachments/20060102/d0d1263b/smime-0001.bin
>> where plugin later today unles you would rather do it? Let me know. > > Looks good (from skimming over the code). I''m returning from our > mountain retreat to the city today, so I likely won''t have time to > write that patch. Feel free to do it, I''ll integrate it later then.I have update the plugin to use your class (removing my Where class in the process, thus breaking old code) and created a descriptive page for the plugin: http://blog.invisible.ch/?p=497 cu jc -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2361 bytes Desc: not available Url : http://wrath.rubyonrails.org/pipermail/rails/attachments/20060102/049e7959/smime.bin
On Jan 2, 2006, at 1:00 PM, Jens-Christian Fischer wrote:>>> where plugin later today unles you would rather do it? Let me know. >> >> Looks good (from skimming over the code). I''m returning from our >> mountain retreat to the city today, so I likely won''t have time to >> write that patch. Feel free to do it, I''ll integrate it later then. > > I have update the plugin to use your class (removing my Where class > in the process, thus breaking old code) and created a descriptive > page for the plugin: > > http://blog.invisible.ch/?p=497 > > cu jcJC- Cool, looks good! I like that you can still use the sql and the between operator as well. I think this will be a pretty useful plugin. Nice job. Cheers- -Ezra Zygmuntowicz WebMaster Yakima Herald-Republic Newspaper ezra@yakima-herald.com 509-577-7732
I just found a problem that I''m not sure how to solve: Converting this: Task.find(:all, :conditions => [''project_id = ?'', self.id] ) to Task.find_with_conditions(:all) do project_id ''='', self.id end breaks horrible, because "self.id" in the block references god knows what (probably the Cond block) instead of the ActiveRecord object. A work around is to use a temporary variable: id = self.id Task.find_with_conditions(:all) do project_id ''='', id end Hmm - not that nice. Any ideas on how to solve that? jc -------------- next part -------------- A non-text attachment was scrubbed... Name: smime.p7s Type: application/pkcs7-signature Size: 2361 bytes Desc: not available Url : http://wrath.rubyonrails.org/pipermail/rails/attachments/20060103/bcb64c0e/smime.bin
On Jan 3, 2006, at 1:31 AM, Jens-Christian Fischer wrote:> I just found a problem that I''m not sure how to solve: > > Converting this: > > Task.find(:all, :conditions => [''project_id = ?'', self.id] ) > > to > > Task.find_with_conditions(:all) do > project_id ''='', self.id > end > > breaks horrible, because "self.id" in the block references god > knows what (probably the Cond block) instead of the ActiveRecord > object. A work around is to use a temporary variable: > > id = self.id > Task.find_with_conditions(:all) do > project_id ''='', id > end > > Hmm - not that nice. Any ideas on how to solve that? > > jcJens- I think that I know a way around it. If you wrap it like "# {self.id}" , I think it will get evaluated before self refers to the Cond class inside the block. Can you try it and confirm that this works?> Task.find_with_conditions(:all) do > project_id ''='', "#{self.id}" > endThanks- -Ezra Zygmuntowicz Yakima Herald-Republic WebMaster http://yakimaherald.com 509-577-7732 ezra@yakima-herald.com