ruby - Rails: route helpers for nested resources -

-

i have nested resources below:

resources :categories   resources :products end

according rails guides,

you can use url_for set of objects, , rails automatically determine route want:

<%= link_to 'ad details', url_for([@magazine, @ad]) %>

in case, rails see @magazine magazine , @ad ad , therefore use magazine_ad_path helper. in helpers link_to, can specify object in place of full url_for call:

<%= link_to 'ad details', [@magazine, @ad] %>

for other actions, need insert action name first element of array:

<%= link_to 'edit ad', [:edit, @magazine, @ad] %>

in case, have following code functional:

<% @products.each |product| %>   <tr>     <td><%= product.name %></td>     <td><%= link_to 'show', category_product_path(product, category_id: product.category_id) %></td>     <td><%= link_to 'edit', edit_category_product_path(product, category_id: product.category_id) %></td>     <td><%= link_to 'destroy', category_product_path(product, category_id: product.category_id), method: :delete, data: { confirm: 'are sure?' } %></td>   </tr> <% end %>

obviously little verbose , wanted shorten using trick mentioned above rails guides.

but if changed show , edit link follows:

<% @products.each |product| %>   <tr>     <td><%= product.name %></td>     <td><%= link_to 'show', [product, product.category_id] %></td>     <td><%= link_to 'edit', [:edit, product, product.category_id] %></td>     <td><%= link_to 'destroy', category_product_path(product, category_id: product.category_id), method: :delete, data: { confirm: 'are sure?' } %></td>   </tr> <% end %>

neither of them works more, , pages complains same thing:

nomethoderror in products#index showing /root/projects/foo/app/views/products/index.html.erb line #16 raised:  undefined method `persisted?' 3:fixnum

what did miss?

the way rails 'automagically' knowing path use inspecting objects pass classes, , looking controller name matches. need make sure passing link_to helper actual model object, , not category_id fixnum , therefore has no associated controller.

<% @products.each |product| %>   <tr>     <td><%= product.name %></td>     <td><%= link_to 'show', [product.category, product] %></td>     <td><%= link_to 'edit', [:edit, product.category, product] %></td>     <td><%= link_to 'destroy', [product.category, product], method: :delete, data: { confirm: 'are sure?' } %></td>   </tr> <% end %>

Comments

Post a Comment

Popular posts from this blog

java - Custom OutputStreamAppender not run: LOGBACK: No context given for <MYAPPENDER> -

-
i wish write custom appender on basis of outputstreamappender . wrote following class package tests; import java.io.ioexception; import java.io.outputstream; import ch.qos.logback.core.outputstreamappender; public class myappender<e> extends outputstreamappender<e> { public myappender() { system.out.println("myappender created"); setoutputstream(new outputstream() { @override public void write(int b) throws ioexception { throw new unsupportedoperationexception(); } }); } } then wrote following runner: package tests; import org.slf4j.loggerfactory; import ch.qos.logback.classic.logger; public class runner { private static final logger log = (logger) loggerfactory.getlogger(runner.class); public static void main(string[] args) { //log.addappender(new myappender<iloggingevent>()); log.info("hello world"); } } finall...
Read more

java - UML - How would you draw a try catch in a sequence diagram? -

-
Image
is there standard way of drawing try catch sequence diagrams? i've made attempt based on this feel end result doesn't feel right. code diagram based around: public static void save () { try { filehandle filehandle = gdx.files.external(file); filehandle.writestring(boolean.tostring(constantshandler.soundenabled)+"\n", false); (int = 0; < 5; i++) { filehandle.writestring(integer.tostring(constantshandler.highscores[i])+"\n", true); } } catch (throwable e) { } } my attempt note: know still need add loop. that's ok. fragments meant show conditional control flow in sequence diagram. superstructures puts limitations on use of fragments (see pp. 467 of ss2.1.1). should use critical region try part above. , option catch . however, keep telling can take quite freedom in using uml. it's language , such changes in life time. long reader ge...
Read more

c++ - No viable overloaded operator for references a map -

-
i trying use map can make tag names reference number. when try , use it, in code error (6 in total every time reference map): src/main.cpp:25:45: error: no viable overloaded operator[] type 'std::map<std::string, std::string>' const char* idcs = node.child_value(tagmap[3]); this code: #include "pugi/pugixml.hpp" #include <iostream> #include <string> #include <map> int main() { pugi::xml_document doca, docb; std::map<std::string, pugi::xml_node> mapa, mapb; std::map<std::string, std::string> tagmap {{"1", "data"}, {"2", "entry"}, {"3", "id"}, {"4", "content"}}; if (!doca.load_file("a.xml") || !docb.load_file("b.xml")) { std::cout << "can't find input files"; return 1; } (auto& node: doca.child(tagmap[1]).children(tagmap[2])) { co...
Read more