I have a method in a iOS application that is querying a database and then putting the data in a ruby loop. I have the loop working to dynamically add a number to the ruby loop but it is pulling up all the users.
# Query all children in database
child = Child.all
# Loop through children and add count.
count = child.count
0.upto(count - 1) do |c|
p "#{#child.each do |child| child.first_name end}" + "['#{c}']"
end
With this set of query and loop it is giving me the following answers:
"[Child:0x8dee0, Child:0x8de2860]['0']",
"[Child:0x8dee0, Child:0x8de2860]['1']"
Instead of giving me the same child for each number I need it to query answers as follows:
"[Child:0x8dee0]['0']",
"[Child:0x8de2860]['1']"
Any help would be greatly appreciated. Thank You.
If your loop is trying to print the first names of the children in your array,
try this:
0.upto(count - 1) do |c|
p child[c].first_name
end
Alternatively, you could skip the count altogether:
child.each do |achild|
p achild.first_name
end
Related
So, What I'm trying to do is make calls to a Reporting API to filter by all possible breakdowns (breakdown the reports by site, avertiser, ad type, campaign, etc...). But, one issue is that the breakdowns can be unique to each login.
Example:
user1: alice123's reporting breakdowns are ["site","advertiser","ad_type","campaign","line_items"]
user2: bob789's reporting breakdowns are ["campaign","position","line_items"]
When I first built the code for this reporting API, I only had one login to test with, so I hard coded the loops for the dimensions (["site","advertiser","ad_type","campaign","line_items"]). So what I did was pinged the API for a report by sites. Then for each site, pinged for advertisers, and each advertiser, I pinged for the next dimension and so on..., leaving me with a nested loop of ~6 layers.
basically what I'm doing:
sites = mechanize.get "#{base_ur}/report?dim=sites"
sites = Yajl::Parser.parse(sites.body) # json parser
sites.each do |site|
advertisers = mechanize.get "#{base_ur}/report?site=#{site.fetch("id")}&dim=advertiser"
advertisers = Yajl::Parser.parse(advertisers.body) # json parser
advertisers.each do |advertiser|
ad_types = mechanize.get "#{base_ur}/report?site=#{site.fetch("id")}&advertiser=#{advertiser.fetch("id")}&dim=ad_type"
ad_types = Yajl::Parser.parse(ad_types.body) # json parser
ad_types.each do |ad_type|
...and so on...
end
end
end
GET <api_url>/?dim=<dimension to breakdown>&site=<filter by site id>&advertiser=<filter by advertiser id>...etc...
At the end of the nested loop, I'm left with a report that's broken down as much granularity as possible.
This works now since I only thought that there was one path of breaking down, but apparently each account could have different dimensions breakdowns.
So what I'm asking is if given an array of breakdowns, how can I set up a nested loop to traverse down dynamically do the granularity singularity?
Thanks.
I'm not sure what your JSON/GET returns exactly but for a problem like this you would need recursion.
Something like this perhaps? It's not very elegant and can definitely be optimised further but should hopefully give you an idea.
some_hash = {:id=>"site-id", :body=>{:id=>"advertiser-id", :body=>{:id=>"ad_type-id", :body=>{:id=>"something-id"}}}}
#breakdowns = ["site", "advertiser", "ad_type", "something"]
def recursive(some_hash, str = nil, i = 0)
if #breakdowns[i+1].nil?
str += "#{#breakdowns[i]}=#{some_hash[:id]}"
else
str += "#{#breakdowns[i]}=#{some_hash[:id]}&dim=#{#breakdowns[i + 1]}"
end
p str
some_hash[:body].is_a?(Hash) ? recursive(some_hash[:body], str.gsub(/dim.*/, ''), i + 1) : return
end
recursive(some_hash, 'base-url/report?')
=> "base-url/report?site=site-id&dim=advertiser"
=> "base-url/report?site=site-id&advertiser=advertiser-id&dim=ad_type"
=> "base-url/report?site=site-id&advertiser=advertiser-id&ad_type=ad_type-id&dim=something"
=> "base-url/report?site=site-id&advertiser=advertiser-id&ad_type=ad_type-id&something=something-id"
If you are just looking to map your data, you can recursively map to a hash as another user pointed out. If you are actually looking to do something with this data while within the loop and want to dynamically recreate the loop structure you listed in your question (though I would advise coming up with a different solution), you can use metaprogramming as follows:
require 'active_support/inflector'
# Assume we are given an input of breakdowns
# I put 'testarr' in place of the operations you perform on each local variable
# for brevity and so you can see that the code works.
# You will have to modify to suit your needs
result = []
testarr = [1,2,3]
b = binding
breakdowns.each do |breakdown|
snippet = <<-END
eval("#{breakdown.pluralize} = testarr", b)
eval("#{breakdown.pluralize}", b).each do |#{breakdown}|
END
result << snippet
end
result << "end\n"*breakdowns.length
eval(result.join)
Note: This method is probably frowned upon, and as I've said I'm sure there are other methods of accomplishing what you are trying to do.
Before anything, I have read all the answers of Why doesn't Ruby support i++ or i—? and understood why. Please note that this is not just another discussion topic about whether to have it or not.
What I'm really after is a more elegant solution for the situation that made me wonder and research about ++/-- in Ruby. I've looked up loops, each, each_with_index and things alike but I couldn't find a better solution for this specific situation.
Less talk, more code:
# Does the first request to Zendesk API, fetching *first page* of results
all_tickets = zd_client.tickets.incremental_export(1384974614)
# Initialises counter variable (please don't kill me for this, still learning! :D )
counter = 1
# Loops result pages
loop do
# Loops each ticket on the paged result
all_tickets.all do |ticket, page_number|
# For debug purposes only, I want to see an incremental by each ticket
p "#{counter} P#{page_number} #{ticket.id} - #{ticket.created_at} | #{ticket.subject}"
counter += 1
end
# Fetches next page, if any
all_tickets.next unless all_tickets.last_page?
# Breaks outer loop if last_page?
break if all_tickets.last_page?
end
For now, I need counter for debug purposes only - it's not a big deal at all - but my curiosity typed this question itself: is there a better (more beautiful, more elegant) solution for this? Having a whole line just for counter += 1 seems pretty dull. Just as an example, having "#{counter++}" when printing the string would be much simpler (for readability sake, at least).
I can't simply use .each's index because it's a nested loop, and it would reset at each page (outer loop).
Any thoughts?
BTW: This question has nothing to do with Zendesk API whatsoever. I've just used it to better illustrate my situation.
To me, counter += 1 is a fine way to express incrementing the counter.
You can start your counter at 0 and then get the effect you wanted by writing:
p "#{counter += 1} ..."
But I generally wouldn't recommend this because people do not expect side effects like changing a variable to happen inside string interpolation.
If you are looking for something more elegant, you should make an Enumerator that returns integers one at a time, each time you call next on the enumerator.
nums = Enumerator.new do |y|
c = 0
y << (c += 1) while true
end
nums.next # => 1
nums.next # => 2
nums.next # => 3
Instead of using Enumerator.new in the code above, you could just write:
nums = 1.upto(Float::INFINITY)
As mentioned by B Seven each_with_index will work, but you can keep the page_number, as long all_tickets is a container of tuples as it must be to be working right now.
all_tickets.each_with_index do |ticket, page_number, i|
#stuff
end
Where i is the index. If you have more than ticket and page_number inside each element of all_tickets you continue putting them, just remember that the index is the extra one and shall stay in the end.
Could be I oversimplified your example but you could calculate a counter from your inner and outer range like this.
all_tickets = *(1..10)
inner_limit = all_tickets.size
outer_limit = 5000
1.upto(outer_limit) do |outer_counter|
all_tickets.each_with_index do |ticket, inner_counter|
p [(outer_counter*inner_limit)+inner_counter, outer_counter, inner_counter, ticket]
end
# some conditional to break out, in your case the last_page? method
break if outer_counter > 3
end
all_tickets.each_with_index(1) do |ticket, i|
I'm not sure where page_number is coming from...
See Ruby Docs.
My question is, how can I search through an array and replace the string at the current index of the search without knowing what the indexed array string contains?
The code below will search through an ajax file hosted on the internet, it will find the inventory, go through each weapon in my inventory, adding the ID to a string (so I can check if that weapon has been checked before). Then it will add another value after that of the amount of times it occurs in the inventory, then after I have check all weapon in the inventory, it will go through the all of the IDs added to the string and display them along with the number (amount of occurrences). This is so I know how many of each weapon I have.
This is an example of what I have:
strList = ""
inventory.each do |inv|
amount = 1
exists = false
ids = strList.split(',')
ids.each do |ind|
if (inv['id'] == ind.split('/').first) then
exists = true
amount = ind.split('/').first.to_i
amount += 1
ind = "#{inv['id']}/#{amount.to_s}" # This doesn't seem work as expected.
end
end
if (exists == true) then
ids.push("#{inv['id']}/#{amount.to_s}")
strList = ids.join(",")
end
end
strList.split(",").each do |item|
puts "#{item.split('/').first} (#{item.split('/').last})"
end
Here is an idea of what code I expected (pseudo-code):
inventory = get_inventory()
drawn_inv = ""
loop.inventory do |inv|
if (inv['id'].occurred_before?)
inv['id'].count += 1
end
end loop
loop.inventory do |inv|
drawn_inv.add(inv['id'] + "/" + inv['id'].count)
end loop
loop.drawn_inv do |inv|
puts "#{inv}"
end loop
Any help on how to replace that line is appreciated!
EDIT: Sorry for not requiring more information on my code. I skipped the less important part at the bottom of the code and displayed commented code instead of actual code, I'll add that now.
EDIT #2: I'll update my description of what it does and what I'm expecting as a result.
EDIT #3: Added pseudo-code.
Thanks in advance,
SteTrezla
You want #each_with_index: http://ruby-doc.org/core-2.2.0/Enumerable.html#method-i-each_with_index
You may also want to look at #gsub since it takes a block. You may not need to split this string into an array at all. Basically something like strList.gsub(...){ |match| #...your block }
Currently trying to generate a random number in a specific range;
and ensure that it would be unique against others stored records.
Using Mysql. Could be like an id, incremented; but can't be it.
Currently testing other existing records in an 'expensive' manner;
but I'm pretty sure that there would be a clean 1/2 lines of code to use
Currently using :
test = 0
Order.all.each do |ord|
test = (0..899999).to_a.sample.to_s.rjust(6, '0')
if Order.find_by_number(test).nil? then
break
end
end
return test
Thanks for any help
Here your are my one-line solution. It is also the quicker one since calls .pluck to retrieve the numbers from the Order table. .select instantiates an "Order" object for every record (that is very costly and unnecessary) while .pluck does not. It also avoids to iterate again each object with a .map to get the "number" field. We can avoid the second .map as well if we convert, using CAST in this case, to a numeric value from the database.
(Array(0...899999) - Order.pluck("CAST('number' AS UNSIGNED)")).sample.to_s.rjust(6, '0')
I would do something like this:
# gets all existing IDs
existing_ids = Order.all.select(:number).map(&:number).map(&:to_i)
# removes them from the acceptable range
available_numbers = (0..899999).to_a - existing_ids
# choose one (which is not in the DB)
available_numbers.sample.to_s.rjust(6, '0')
I think, you can do something like below :
def uniq_num_add(arr)
loop do
rndm = rand(1..15) # I took this range as an example
# random number will be added to the array, when the number will
# not be present
break arr<< "%02d" % rndm unless arr.include?(rndm)
end
end
array = []
3.times do
uniq_num_add(array)
end
array # => ["02", "15", "04"]
I am using Twitter gem (1.7.1) in ruby. I want to get my member of my list on Twitter but I just get last twenty members. How can I get more than twenty members?
listmembers = client.list_members(username, listname)
listmembers.users.each do |lmname|
p lmname.screen_name
end
First, pass an argument "cursor=-1". You then get the first 20. The Twitter API will return a field called "next_cursor" - pass this to the cursor and you get the next 20.
Example (pseudocode):
cursor = -1
do {
# get data, using the cursor
data = {}
cursor = data.next_cursor
} while (len(data) > 0) # Loop while we're still getting data back
More info on https://dev.twitter.com/docs/api/1/get/lists/members
I solved my problem with using "cursor". This solution helped me quite.
How to use Twitter Api To Get more than 20 list Members in a single request?
I edited the code for ruby. My code is that; I kept an integer value,
pagevalue = 0
if (listmembers.next_cursor == 0) # it means we have only one page
listmembers.users.each do |lmname|
p lmname.screen_name
end
end
else # it means we have pages more than one
while (listmembers.next_cursor != 0)
listmembers.users.each do |lmname|
p lmname.screen_name # check screen_name is nil or not
end
end
pagevalue = listmembers.next_cursor
listmembers = client.list_members(username, listname, :cursor => pagevalue)
if (listmembers.next_cursor == 0) # for last page
listmembers.users.each do |lmname|
p lmname.screen_name
end
end
end
if you get screen_name nil in while it won't work. So, check your screen_name if it exists or not.