Rails 3 experiencing issues with AJAX calls

Question

Rails 3 experiencing issues with AJAX calls

Struggling to troubleshoot my AJAX call in rails 3, I find myself hopelessly confused. On an index page, there's a table listing objects with detail links. The HAML layout appears as:

%h1
  Step 1: Create/upload your CV
#europasslogo
%table.index
  %tr
    %th.bottom_border= 'CV ID'
    %th.bottom_border= 'CV Title'
    %th.bottom_border= 'Links'
  - @cvs.each do |cv|
    %tr
      %td.cell= cv.id
      %td.cell= cv.name
      %td.cell
        = link_to 'Matching', match_resume_url(cv.id)
        &nbsp;
        = link_to "Details", cv_path(cv.id), {:remote => true, :method => :get}
.clear
#details

The goal is for the response of clicking the "details" link to be displayed in the #details div at the bottom, simply showing the CV output as plaintext.

In the controller, I've set up the following:

class CvsController < ApplicationController
  def new
    @cvs = Cv.all
  end

  def show
    cv = Cv.find params[:id]
    @data = IO.readlines("public/cvs/#{cv.id}.xml", "").to_s
    render :layout => false
  end

  def match
    @cv = Cv.find params[:id]
    @language = Language.find_or_create_by_code :en
    @vacancies = Vacancy.joins(:vacancy_occupations).where('vacancy_occupations.concept_id' => @cv.occupations.collect{|o| o.id}).uniq
  end
end

The server receives and processes the AJAX request when the link is clicked, showcasing the response in Firebug console as well:

Started GET "/cvs/2" for 192.168.33.82 at Fri May 13 00:55:49 -0700 2011
  Processing by CvsController#show as JS
  Parameters: {"id"=>"2"}
  Cv Load (0.1ms)  SELECT `cvs`.* FROM `cvs` WHERE `cvs`.`id` = 2 LIMIT 1
Rendered cvs/show.js.haml (2.1ms)
Completed 200 OK in 69ms (Views: 4.3ms | ActiveRecord: 0.1ms)

The AJAX call is successfully received and processed by the server. The show.js.haml file shows:

= "$('details').html(#{@data});"

Despite the large files involved, it seems a lot of generated Javascript code is present. Struggling with limited knowledge in Javascript, I'm puzzled why such a seemingly simple task proves challenging. All I wish for is when the link is clicked, all content within the @data variable integrates into my details section...

javascript ajax ruby-on-rails-3

Answer 1

Answer №1

When you use = "$('details').html(#{@data});" in HAML, the code will be escaped.

If you use

!= "$('details').html(#{@data});"

, the code will be executed and replace the content.

It's important to note that using 'details' as a selector might not be correct. Typically, you should use '#details' if it represents an ID.

Answer 2

When you use = "$('details').html(#{@data});" in HAML, the code will be escaped.

If you use

!= "$('details').html(#{@data});"

, the code will be executed and replace the content.

It's important to note that using 'details' as a selector might not be correct. Typically, you should use '#details' if it represents an ID.

Answer 3

Answer №2

Separating JavaScript from server-side code can greatly reduce headaches. Your controller simply reads a file and loads it on the page, a task that can be efficiently handled entirely in JS:

CV link

= link_to "Details", cv_path(cv.id), :'data-cv-id' => cv.id

JS wireup

$('table.index').delegate('a[data-cv-id]', 'click', function (e) {
  var id = $(e.target).data('cv-id');
  $.ajax({
    type: 'GET',
    url: '/cv/' + id + '.xml',
    dataType: 'xml',
    success: function (xml) {
      $('#detail').html(xml);
    }
  });
  e.preventDefault();
});

(shameless plug) Check out my jquery plugin for an even easier approach:

$('table.index').delegate('a[data-cv-id]', 'click', function (e) {
  $.read('/cv/{id}.xml', { id: $(e.target).data('cv-id') })
   .then(function (xml) {
     $('#details').html(xml);
   });
  e.preventDefault();
});

JS wireup - Prototype

Try using Prototype.js with this example:

var table = $$('table.index')[0];
$(table).on('a[data-cv-id]', 'click', function (event, element) {
  new Ajax.Request('/cv/' + event.getAttribute('data-cv-id') + '.xml', {
    method: 'get',
    onSuccess: function (transport) {
      //do something with transport.responseXML
      //not sure how to write Prototype code for this bit
    }
  });
  Event.stop(event);
});

You can enhance separation of concerns by utilizing amplify.request, as well as exploring JS templating systems like Handlebars.

Although it may be tempting to mix Rails templates with Javascript, this approach often proves troublesome. It's more effective to design your controllers as JSON/XML service APIs and handle data requests/templating in JavaScript.

Rails removed RJS for a reason: unnecessary connections between server-side and front-end code increase application fragility and maintenance complexity over time. Your controller shouldn't rely on markup within your templates.

Answer 4

Separating JavaScript from server-side code can greatly reduce headaches. Your controller simply reads a file and loads it on the page, a task that can be efficiently handled entirely in JS:

CV link

= link_to "Details", cv_path(cv.id), :'data-cv-id' => cv.id

JS wireup

$('table.index').delegate('a[data-cv-id]', 'click', function (e) {
  var id = $(e.target).data('cv-id');
  $.ajax({
    type: 'GET',
    url: '/cv/' + id + '.xml',
    dataType: 'xml',
    success: function (xml) {
      $('#detail').html(xml);
    }
  });
  e.preventDefault();
});

(shameless plug) Check out my jquery plugin for an even easier approach:

$('table.index').delegate('a[data-cv-id]', 'click', function (e) {
  $.read('/cv/{id}.xml', { id: $(e.target).data('cv-id') })
   .then(function (xml) {
     $('#details').html(xml);
   });
  e.preventDefault();
});

JS wireup - Prototype

Try using Prototype.js with this example:

var table = $$('table.index')[0];
$(table).on('a[data-cv-id]', 'click', function (event, element) {
  new Ajax.Request('/cv/' + event.getAttribute('data-cv-id') + '.xml', {
    method: 'get',
    onSuccess: function (transport) {
      //do something with transport.responseXML
      //not sure how to write Prototype code for this bit
    }
  });
  Event.stop(event);
});

You can enhance separation of concerns by utilizing amplify.request, as well as exploring JS templating systems like Handlebars.

Although it may be tempting to mix Rails templates with Javascript, this approach often proves troublesome. It's more effective to design your controllers as JSON/XML service APIs and handle data requests/templating in JavaScript.

Rails removed RJS for a reason: unnecessary connections between server-side and front-end code increase application fragility and maintenance complexity over time. Your controller shouldn't rely on markup within your templates.

Answer 5

Answer №3

Thank you for the feedback everyone! With some assistance from a friend, I was able to resolve the issue.

Within the controller, I utilized the following code:

@cv = Cv.find params[:id]
doc = REXML::Document.new File.open "public/cvs/#{@cv.id}.xml"
@data = REXML::XPath.first(doc.root, "identification").text
@data << REXML::XPath.first(doc.root, "application").text
@data << REXML::XPath.first(doc.root, "workexperiencelist").text

# Displaying the partial
render(:update) { |page| page.replace_html 'details', :partial => 'cvs/show', :layout => false}

This code effectively loads all necessary data and renders a partial view. The final command works its magic and triggers the needed javascript for updates. Personally, I find this method much easier to comprehend.

Answer 6

Thank you for the feedback everyone! With some assistance from a friend, I was able to resolve the issue.

Within the controller, I utilized the following code:

@cv = Cv.find params[:id]
doc = REXML::Document.new File.open "public/cvs/#{@cv.id}.xml"
@data = REXML::XPath.first(doc.root, "identification").text
@data << REXML::XPath.first(doc.root, "application").text
@data << REXML::XPath.first(doc.root, "workexperiencelist").text

# Displaying the partial
render(:update) { |page| page.replace_html 'details', :partial => 'cvs/show', :layout => false}

This code effectively loads all necessary data and renders a partial view. The final command works its magic and triggers the needed javascript for updates. Personally, I find this method much easier to comprehend.

Rails 3 experiencing issues with AJAX calls

Answer №1

Answer №2

Answer №3

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