I'm using rails 4.2.7.1, ruby 2.3.1. I have a landing page containing an add button which upon clicking pops up a new window (in a new URL). This new window has a form in it. I want the landing page to have a table which is dynamically populated every time the form on the pop-up is submitted (basically re-direct back to the landing page and update the table).
We've an internal framework for creating HTML views as ruby objects (for instance, a table object or a panel object). These are created within the model class and have methods to enable their rendering (essentially use content_tag within the ActionView Helper to render the final HTML from .erb/HAML).
Now, the problem is the controller always ends up calling these methods in the model class every time the page is loaded. Due to this the objects aren't retaining their previous values. I got around this by using class variables but is there a better way to handle this? I haven't explored rails caching yet.
I'd be open to listening to solutions which don't follow the model described above.
Thanks
We've an internal framework for creating HTML views as ruby objects
(for instance, a table object or a panel object). These are created
within the model class and have methods to enable their rendering
(essentially use content_tag within the ActionView Helper to render
the final HTML from .erb/HAML).
I don't want to sound rude, but why? This seems like a huge over-complication and source of errors.
Anyway,
You'll want to look into Websockets. If you can upgrade to Rails 5, ActionCable might be the answer. Otherwise you could have the view update with a simple setInterval.
Related
I want to create several instances of same model form a single form. And more importantly, the number of instances aren't known before form rendering.
I've seen several tutorials of this kind, but unfortunately those didn't suit my need. I've seen Ryan bate's nested form tutorial. But I'm not creating nested form. I've also seen some tutorials, which do create multiple objects, but the number of object's are all known in those cases. One of the tutorial is here - http://archive.railsforum.com/viewtopic.php?id=717
User will click a button and a new set of fields for a new object will be inserted just like the nested form demo from ryanb.
Here is a mockup of what I want. It's basically a very small form fit into a single line.
As i understand you need cocoon gem it allows to add form fields
It sounds like you may need to reach beyond Rails views and utilize javascript to dynamically render more "partials" when the user decides to add more fields. Something like this: Adding input elements dynamically to form
If you want to keep your view rendering logic in rails, you could make an AJAX request to your application, have it return just a partial's worth of html back, and insert the response html into your dom.
I think I already know the answer to this, but I'm going to ask it anyway.
I've got a rails app, and integrating angular into one of the areas of the app to get some of that magic. To add to the mix I'm integrating the Chewy gem to use ElasticSearch.
So, using this example:
I have a Presentation model with the following fields:
id
venue id
presentation id
rating
I have a Presentations view with loops through a Presentation partial and I'm doing essentially the same thing with Angular and I'm looping through a Presentation directive.
Now, with normal ERB when I pull a list of presentations in the ERB view I could just have: <%= presentation.venue.name %> to show the venue's name.
What I'm wondering is, and like I said I think I already know the answer to this, going the angular route through this when I'm looping through my Presentation directive, even though it's an _presentation.html.erb file I can't use the active record relation because javascript get's rendered after the html.
So, in my angular directive template, where instead I would have presentation.venue.name I would need to have an angular function that would pull that in, right?
Is there some way, when I'm pulling the data in through ElasticSearch/Chewy I could pull this data in as well? That's my only other option I believe?
I'm trying to make a drop down menu that has a bunch of items (Amelia, Cerulean, Cosmo, Cyborg, Flatly, Journal). Each of these items represent a css file.
When one of them is selected I want my website to take this selected css file and apply it to the website.
I would like the drop down menu to interact with jquery, meaning when a item is selected jquery takes over and makes a asyn/ajax call to some mvc actionresult.
By the way I'm using MVC 5.
I hope someone can help me sketch the initial groundwork.
I've implemented this in my application.
I'm not sure what to tell you though. It's easier when we have an attempted solution to fix.
Here's an overview of how mine works:
I have created a controller called SharedController. The purpose of it is to contain various actions that render common actions. All of the actions are considered ChildActionOnly.
My _Layout uses RenderAction to render the action NavbarPartial which is in my SharedController.
More importantly the Navbar partial then uses RenderAction to render the action ThemeListPartial. This action is responsible for getting a list of available themes. The list of available themes is determined at applications startup. I've created a ThemeFinder class and ThemeRepository class that are responsible for finding and storing themes. The ThemeFinder finds themes by expressions that you give it. In a new class called App_Start/ThemeConfig I've given it only one expression - "~/Content/themes/{name}.bootstrap.css". This will find all themes with that naming convention in that location.
My razor code will take the ViewModel and display a dropdown menu in the navbar.
To get the themes to change my dropdown menu contains an AJAX link to an action called SaveTheme in ThemeController. This action takes a theme name as a string and tries to save it in a cookie for the user.
If the theme is found and saved successfully, the action responds with a success message.
jQuery then changes the theme by finding the associated link attribute and changing the HREF contents to the new theme. It knows the new theme relative URL because I have it stored in data attributes.
I completed this before I made the switch to AngularJs. The one thing I plan to go back and change is to cut out as much (maybe all) jQuery as possible and replace it with better code.
I'd like a good source on how to set up controller actions and forms for creating a resource inside the view of another resource that it belongs_to...
Set up your controllers as you would normally. You'll need to use the nested attributes feature of Rails. This enables you to create children objects at the same time as creating their parent using one form.
This is my go-to link for nested attributes. The only change you will need to make if you are running Ruby 1.9.2 is in the setup_person helper. returning has been deprecated so you can change it to:
def setup_person(person)
person.tap do |p|
p.children.build if p.children.empty?
end
end
In typical Rails style, this will just work using standard controllers for each of your resources.
Other links
http://weblog.rubyonrails.org/2009/1/26/nested-model-forms
http://jeffperrin.com/2009/06/04/rails-nested-forms-and-collection_select/
I don't have a web source that documents what I usually do, but I created a gist that documents what I do most often here: https://gist.github.com/900241
The premise of the gist is that you have a project model with many project roles, and you want to edit many project roles in the project form. This is pretty much the classic accepts_nested_attributes_for scenario, and just about any page that talks about it will give you a decent writeup. The problem is, the solutions I've seen have always involved some seriously messy obtrusive JavaScript that escaped your entire form view and threw it in the onClick method of a link. I recently came up with a cleaner unobtrusive approach using jQuery templates.
You don't have to do a thing to your ProjectsController when you move to a nested model. Everything Just Works at the controller level, and you don't even need a ProjectRolesController. (This is why I didn't bother including them in the gist.) At the model level, it's just standard accepts_nested_attributes_for. Where it gets interesting is in the view.
The project form has two form_for blocks: one rendering a jQuery template, and another rendering the project roles form. The jQuery template in turn just renders the project roles form (mmm DRY!), but from within a <script> tag, and with a blank project role. Because the form is within a script tag, it won't get submitted along with the project form, and because the script type is "text/x-jquery-tmpl", this is completely valid markup.
When the user clicks on "Add a Project Role", it fires some jQuery that takes the form within the template, replaces the index with the current date (this is all so this project role can be uniquely identified), and appends it to the end of the project roles section of the form.
When the user clicks on "Delete" next to a project role, it checks to see if this project role is a new record, and if not, it appends a "_delete" hidden field to the end of the form. In either case, it removes the project role div from the DOM.
I suppose it should do justice to state what I think I know so far as well as what I've done:
1) I created the app and did my first db migration; I now have my dev, test and production databases. The dev db has a table called 'wines'.
2) I made a scaffold which created the necessary files.
3) The basic index/update/destroy methods are set up and I can browse the pages.
4) From what I gather, the ActiveRecord class "Wine" automatically inherits properties from the database? Each column is a property and each row in the table 'wines' is a potentially instantiated object which is called from the wine_controller script.
The problem I'm having now is that I want to create a common layout that all controllers use. The only things that will change will be the page title, potentially some <link> tags in the header, the <body> attributes (javascript onload events most likely) and whatever lies inside the <body> tag.
I find myself looking up functions that will do what I want (like "favicon_link_tag", "stylesheet_link_tag" and "auto_discovery_link_tag"...) but I can't find the right place to PUT them! I know this has something to do with my lack of understanding of how things are executed/inherited. For example if I were to declare #pageTitle in application_controller.rb and use #pageTitle in ApplicationHelper it won't work. Or even using "stylesheet_link_tag" in application_controller.rb throws an error. I'm just not getting something.
How does each thing relate to another in terms of chronological execution, scope, etc.?
In your "app/views" directory there is a folder called "layouts." By default there should be an "application.html.erb" file in there, but if there isn't you can create it.
Your "application" layout file is the default layout file used by any view. However, if you want a particular controller to use a different view, you can override this. See this railscast, and this one is helpful too.
The main thing to understand is the content from any particular view will show up wherever the yield method appears in your application layout. The main 'yield' block gets the view file specified by your controller action, but you can mark anything inside any view to be passed to another yield block instead. For instance, the "title" example you gave could be passed to the head of your application layout. See this railscast for a detailed example of that.
For more, you should read the Rails Guide, and you might want to consider picking up a Rails starter book.
I got my feet wet with "Beginning Rails 3," which was a phenomenal introduction to the framework. A couple days with that book and it was all making sense to me, and I was developing faster than I ever had before. Rails rocks once you get to know it, but it's definitely worth going through a book.
Please continue to ask questions, I'll help if I can :)
-EDIT- To answer your question about control flow, it basically works like this:
Your browser sends a GET request for a particular URL.
The router takes that request, matches it to a controller action, triggers that controller action, and provides the controller any parameters associated with the request. For instance: if you requested example.com/posts/123?color=red this would trigger the SHOW action of your posts_controller, and would pass {:color => 'red'} to the params hash. You would access that using params[:color]
The controller action does its thing, and when it's done it renders output. By default it renders whatever view is located in app/<controller_name>/<action_name>, and will whichever file matches the extension appropriate to the request (ie an AJAX request would trigger <action_name>.js.erb and a GET request would trigger <action_name>.html.erb.
You can override this using the render method, for example by passing render 'foo/bar' to render using the view for FooController, Bar action instead of your current action.
Note that no matter what you render, the data available to the view is whatever is in the specific controller action the router triggered, not the controller action that would 'normally' render that view.
The view file is parsed using the data from the controller that called it. If you have any content_for methods then the view code that is inside the content_for block will go where you tell it, otherwise everything else will go to the main YIELD block in your application layout (or whatever layout your controller specified instead).
The application layout is parsed, and the content from the view is inserted into the appropriate areas.
The page is served to the user.
That's a simplification in some ways, but I think it answers your question. Again, feel free to keep asking :)