ruby on rails - Where can we use Gem AASM? -


since new ror, want know gem aasm. actually, have ruby code built aasm gem.

it's hard me understand why using gem here.

i want know basic ideas of why/when/where can use gem.

thanks in advance.

the intention allow defined values attribute , allow predefined transitions 1 state only. example, state can transferred in state b or state c, state b can not transferred in state c. in addition aasm offers callback methods controll transitions or before or after transition.

i used aasm within user model ensure user states can changed on predefined ways. see example:

# state machine ---------------------------------------------------------- initial_state = :pending states = {   initial_state    => 'new user accounts initial state',   :waiting         => 'new user account waiting confirmation',   :confirmed       => 'user confirmed registration',   :changing_email  => 'user changed email address',   :blocked         => 'user can not log in',   :anonymized      => 'personal user data deleted',   :not_deletable   => 'can not delete user, because has content' }  include aasm attr_protected :state aasm({:column => :state})   states.keys.each |key|     state(key, (key == initial_state ? {:initial => true} : {}))   end    # creates instance methods confirm, confirm! , confirmed? later usage   event :confirm     transitions :to => :confirmed, :from => :waiting     transitions :to => :confirmed, :from => :blocked     transitions :to => :confirmed, :from => :changing_email     transitions :to => :confirmed, :from => :not_deletable   end end

in event block define how user state can become confirmed. therefore user.state attribute has "waiting", "blocked", "changing_email" or "not_deleteable". in these cases can call magic methods aasm brings in.

user.confirmed? # => false

now can confirm user.

user.confirm user.state # => confirmed

or

user.confirm!  # => true user.state # => confirmed

now

user.confirmed? # => true

if user has state "anonymized" can't confirm , error. way user instances have defined states @ time. can't make mistake while changing user state. defined methods aasm only. defined states , defined transitions possible do.


Comments

Post a Comment

Popular posts from this blog

authentication - Mongodb revoke acccess to connect test database -

i have ec2 instance mongodb 3.2.0 installed. have user admin access. can connect user , perform operation remotely. 1 can connect database test remote if knows ip mongo 11.11.11.11. although not able make operations, want restrict access user credentials can connect server. first need create users , grant roles users, example: use admin db.createuser( { user: "myuseradmin", pwd: "abc123", roles: [ { role: "useradminanydatabase", db: "admin" } ] } ) then need start server --auth parameter mongod --auth more information here
Read more

r - Update two sets of radiobuttons reactively - shiny -

i have read ( how make choices in radiobuttons reactive in shiny? ) shows me how update radiobutton s in reactive way. however, when try , update 2 sets of buttons same data, 1 set renders. example: server: # create example data wafer <- rep(c(1:3), each=3) length <- c(1,1,2,1,1,1,3,5,1) width <- c(3,1,6,1,1,1,1,1,6) dd <- data.frame(wafer, length, width) shinyserver(function(input, output, session){ # create reactive dataframe store data values <- reactivevalues() values$df <- data.frame() # lengths , widths of wafer user input <- eventreactive(input$do, { subset(dd, wafer %in% input$wafer, select = length:width) }) # update reactive data frame lengths , widths have been selected user input observe({ if(!is.null(a())) { values$df <- rbind(isolate(values$df), a()) } }) output$wl <- renderdatatable({ a() }) # update radio buttons unique length , widths stored in values$df # ever "observe" put first in co...
Read more

ios - Realm over CoreData should I use NSFetchedResultController or a Dictionary? -

i'm working on app using core data , nsfetchedresultcontroller many reasons switch use realm. saw there "realm version" of nsfetchedresultcontroller on github wouldn't compatible current code using core data. the view controller displaying list of people same school, address book. list sublist of people studied in same city. so thinking make 1 unique request database retrieve list of people , filter locally list within 1 dictionary per school [string: anyobject] string section name within tableview , anyobject array of people. first solution, make nsfetchedresultcontroller each school predicate filtering location. delete actions etc.. handled delegates -> not compatible realm create dictionaries , update them each actions... -> works realm it's annoying code. any better solution? edit: i need clarify request: i'd write class inherit uitableviewcontroller. this class has list of people sorted in alphabetical order the tableview has ...
Read more