Pagination fails if some condition is checked in rails

Question

Want to show the records satisfying some condition after retrieving it from the database in Ruby on rails.

Problem is that :

currently I am showing the records using will_paginate gem without checking the condition after retrieving it from database.

and if I check the condition ; some records fail to meet the condition will be eliminated

EDIT

@result=MyRecord.paginate(:per_page => @perpage, :page => params[:page]).all
 #process records for conditions, if i eliminate records from @result that much records will be less for pagination
 @result #modified sent to view

So how to show the pagination for this.

Is their any alternative way to do the pagination after retrieving the records???

show us what you are doing at the moment, no code = limited help — Richlewis, Jan 08 '13 at 12:37
what conditions? what are you paginating? cant answer a question when theres nothing to go on, you need to post some code — Richlewis, Jan 08 '13 at 12:50
well there was as poor question.. so what conditions are you passing before hand? do you want to show all results excluding conditions or do you want to only show the results that meet the condition? — Richlewis, Jan 08 '13 at 12:59
But conditions cannot be checked from query where clause ...It is massive calculation — Mohammad Sadiq Shaikh, Jan 08 '13 at 13:01
and what is the code for the condition? cmon help us out here, is your condition wrapped in a method? or is it a scope? — Richlewis, Jan 08 '13 at 13:01
'RADIUS=6371 def distance_between(lat1, lon1, lat2, lon2) d_lat = toRad(lat2-lat1) d_lon = toRad(lon2-lon1) a = Math.sin(d_lat/2) * Math.sin(d_lat/2) + Math.cos(toRad(lat1)) * Math.cos(toRad(lat2)) *Math.sin(d_lon/2) * Math.sin(d_lon/2) c = 2 * Math.atan2(Math.sqrt(a), Math.sqrt(1-a)) d =RADIUS * c return d end' — Mohammad Sadiq Shaikh, Jan 08 '13 at 13:05
yeah thats great but how are you calling the calculation? method? if so what is your method called — Richlewis, Jan 08 '13 at 13:06
i am passing the lat lng of each successive points for checking distance — Mohammad Sadiq Shaikh, Jan 08 '13 at 13:09
You are incapable to understand the problem...That does not mean the question is poor .Remember this before down voting for any question... — Mohammad Sadiq Shaikh, Jan 08 '13 at 13:25
yeah think you mean i am incapable of understanding the problem, the question was unclear, had no examples and did not show any research effort — Richlewis, Jan 08 '13 at 13:31
There is much more to research in my question only to those who can understand it... see the below answer he is one of them.... — Mohammad Sadiq Shaikh, Jan 08 '13 at 13:40

score 1 · Answer 1 · edited May 23 '17 at 12:04

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If I understood correctly, if you are getting less records which in turn not giving pagination then you can explicitly define your pagination for the number of records you want with the attribute :per_page. So if you are getting only five records from database then define :per_page => 5 in your query to get the pagination.

This way you can go -

@result=MyRecord.paginate(:per_page => 5, :page => params[:page]).all

For varying results, WillPaginate::Collection will also help -

Check this post of SO - rails pagination - different per_page value page 1 from subsequent pages

edited May 23 '17 at 12:04

Community

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answered Jan 08 '13 at 13:10

sjain

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I am retriving per page 10 records .but @result is to be procesed to meet my condition . if some records fails to meet it .Total records will be reduced for that page.... – Mohammad Sadiq Shaikh Jan 08 '13 at 13:13
I edited my post to give you the better solution that you want. Check my updated answer above. – sjain Jan 08 '13 at 13:27

Pagination fails if some condition is checked in rails

1 Answers1