I'm trying to build a website that users create contents of a table and display them. I'm using Ruby on Rails to work on this project. So far I can let users create new rows and display, which is nearly a default function when building an application.
However, I need to know how to limit the number of rows, let's say 15 rows at once, then a user needs to click next button or navigation number (ex, 1,2,3...5) to call next 15 rows of data in the table.
I'm not really sure how to approach this matter.
If I can help on this, that would be a great help.
Thanks!
The easiest way to do what you want is with pagination. There are a number of gems which offer this but I find kaminari the most robust and flexible of these.
Install the Kaminari Gem
https://github.com/kaminari/kaminari -- Add to you gemfile and run bundle install
gem 'kaminari'
Call the Kaminari method in the controller
In your controller, make sure the object collections uses the kaminari method.
#model = Model.all.order(:name).page(params[:page]).per(15)
This is most likely pretty obvious, but just for clarity: The order by is not required for kaminari, the page method will take the parameters from the URL (params are added to the URL when a user clicks on a certain page number or clicks next or prev), and the per method is the number of records allowed on each page.
Add pagination to your view
Now in your view - just call the pagination helper with your object to add the pagination links (Prev 1 2 3 4 5 Next)
= paginate #model
You can also change the look and feel the pagination links, just read the documentation, it's pretty straighforward.
Since this is your first post I will also add:
WELCOME!! Thanks for your post. New questions keep the community on their toes.
Next time you post, keep in mind that everyone here is happy to help, but if you add a few things to your post the answers will come quicker and you won't be downvoted:
Add code snippets and samples to your post, its easier for answers to come if they can see your work and also improves answers if they can mock up code responses based on your original question, less confusion that way
Give links to tutorials you might be using
State what you've tried, and why it's not working as you'd expect / prefer
Related
My application feature a "main" page where most of the action happens: There are tags for filtering and a list of results in a (paginated) table, plus the possibility to select some or all results in a "shopping cart".
This page has to keep track of a whole lot of things: what tags are selected, what items are selected, and how the result table is sorted and what page it's on. Everything has to persist, so if I select a new tag, the page must partially reload but remember everything (sorting, what's selected).
Right now I'm handling everything with parameters, and for each action taken on the page, all links (select a tag/item, change page, sort table) are updated to include previous parameters + the relevant new addition. This works, obviously, but it feels kind of inefficient, as I have to reload more of the page than I want to. How is this situation normally handled? I can't find that much info on google at all, but it doesn't feel like a particularly uncommon case.
tl;dr: How to best make sure all links (to the same page) always include everything previously selected + the new action. There are a lot of links (one per tag to select/deselect, one per result item to select/deselect, one per sort option, one per page)
There are five ways to do that:
Method 1: By parameters
You mentioned this. I never think of this as it's too troublesome. Anyway it's still a solution for very simple case.
Method 2: By cookie
Save the settings to a cookie and read the cookie in controller to arrange layout settings.
Method 3: By LocalStorage
Similar to cookie but allows more space.
Method 4: By Session
If you are using ActiveRecord to save session, this could be the best solution for pure pages loading. Save the user preferences into session and load it in next layout.
Method 5: Use Ajax
This is the best solution IMO. Instead of whole page loading, use Ajax to refresh/retrieve changes you need. Using together with above method, a user can even continue his last preferences. This is the most powerful and should be applicable to your case which looks like a web app than a website.
Have you tried creating model for all those attributes? and just always load the 'latest' when on the page load, if you dont need them you can always have a flag for that session.
I'm new to rails, and right now I've got a simple application with a controller and view. The page loads up and the controller does a ton of http requests (can't change this) and populates an array of structs. The controller sorts it and the view iterates through and displays it in a table.
I would like the user to be able to click one of several buttons and sort the data in different ways. Right now, I simply pass a :sort variable with a page reload, sort a different way and voila. But, I was wondering if there was a way to sort this array without having to repopulate it. This might be a super simple question and I'm just not searching for the right thing. Basically, can I pass the array back to the controller so it can sort and reload the page? Thanks for any help.
There is a good cast about sorting, I'm sure you find your answer here: http://asciicasts.com/episodes/240-search-sort-paginate-with-ajax
you can use JQuery table which will not fires the server request.
For Demo check
http://datatables.net/
Just wondering what the shorthand would be in Rails to do this (if any):
I have views/pages/ containing 5 html.erb files and they all use the same default layout.html.erb, with one yield statement in the middle of it (the standard setup).
Now I want one view that incorporates all 5 of those erb files above contiguously, one after the other, in place of the one existing yield statement in that same layout.html.erb.
What minimal changes would I make to the layout.html.erb to accomplish this.
(Rails Newbie - like it more than Django now).
Ah,
I see what you're saying. Try this. Have your file structure such that all the views for said controller are in one folder...
#controllers_views = Dir.glob("your/controllers/views/*.erb")
#controllers_views.each { |cv| puts cv }
Seems like that would work, I'm away from my dev box or I'd test it for you.
Hope that helps.
Good luck!
You could always have a javascript that requests the sequential yields at a time interval as an ajax request. Then just your target element change to reflect the updated information.
Alternatively load all 5 into different divisions, and have them revolve visibility, like a picture gallery. CSS3 could pull this off.
http://speckyboy.com/2010/06/09/10-pure-css3-image-galleries-and-sliders/
I want to create a tagging system like seen here on Stack Overflow or on Quora. It'll be its own model, and I'm planning on using this autocomplete plugin to help users find tags. I have a couple of questions:
I want tags to be entirely user-generated. If a user inputs a new tag by typing it and pressing an "Add" button, then that tag is added to the db, but if a user types in an existing tag, then it uses that one. I'm thinking of using code like this:
def create
#video.tags = find_or_create_by_name(#video.tags.name)
end
Am I on the right track?
I'd like to implement something like on Stack Overflow or Quora such that when you click a tag from the suggested list or click an "Add" button, that tag gets added right above the text field with ajax. How would I go about implementing something like that?
I know this is kind of an open-ended question. I'm not really looking for the exact code as much as a general nudge in the right direction. Of course, code examples wouldn't hurt :)
Note I am NOT asking for help on how to set up the jQuery autocomplete plugin... I know how to do that. Rather, it seems like I'll have to modify the code in the plugin so that instead of the tags being added inside the text field, they are added above the text field. I'd appreciate any direction with this.
mbleigh's acts_as_taggable_on gem is a feature-complete solution that you should definitely look into a little more closely. The implementation is rock-solid and flexible to use. However, it is mostly concerned with attaching tags to objects, retrieving tags on objects, and searching for tagged items. This is all backend server stuff.
Most of the functionality you are looking to change (based on your comments) is actually related more to your front-end UI implementation, and the gem doesn't really do much for you there. I'll take your requests one-by-one.
If user inputs a new tag, that tag
gets added, if user inputs an
existing tag, the existing tag gets
used. acts_as_taggable_on does this.
Click a tag from suggested list to
add that tag. This is an
implementation issue - on the
back-end you'll need to collect the
suggested list of tags, then display
those in your presentation as links
to your processing function.
Autocomplete as user enters
potential tag. You'll use the jQuery
autocomplete plugin against a list
of items pulled off the tags table.
With additional jQuery, you can
capture when they've selected one of
the options, or completed entering
their new tag, and then call the
processing function.
Restrict users to entering only one
tag. This will be your UI
implementation - once they've
entered or selected a tag, you
process it. If they enter two words
separated by a comma, then before or
during processing you have to either
treat it as one tag, or take only
the text up to the first comma and
discard the rest.
When you process the addition of a
tag, you will have to do two things.
First, you'll need to handle the UI
display changes to reflect that a
tag has been entered/chosen. This
includes placing the tag in the
"seleted" area, removing it from the
"available" display, updating any
counters, etc. Second, you'll need
to send a request to the server to
actually add the tag to the object
and persist that fact to the
database (where the taggable gem will take over for you). You can either do this via
an individual AJAX request per tag,
or you can handle it when you submit
the form. If the latter, you'll need
a var to keep the running list of
tags that have been added/removed
and you'll need code to handle
adding/removing values to that var.
For an example of saving tags while editing but not sending to server/db until saving a form, you might take a look at the tagging functionality on Tumblr's new post page. You can add/remove tags at will while creating the post, but none of it goes to the database until you click save.
As you can see, most of this is on you to determine and code, but has very little to do with the backend part. The gem will take care of that for you quite nicely.
I hope this helps get you moving in the right direction.
The more I try to force the acts-as-taggable-on gem to work the more I think these are fundamentally different types of problems. Specifically because of aliases. The gem considers each tag to be its own special snowflake, making it difficult to create synonyms. In some cases it doesn't go far enough, if you want the Tag to have a description you'd need to edit the given migrations (which isn't hard to do).
Here's what I'm considering implementing, given the trouble I've had implementing via the gem. Let's assume you want to create a tagging system for Technologies.
Consider the following psuedo code, I haven't yet tested it.
rails g model Tech usage_count::integer description:text icon_url:string etc. Run the migration. Note the
Now in the controller you will need to increment usage_count each time something happens, the user submits a new question tagged with given text.
rails g model Name::Tech belongs_to:Tech name:string
Name::Tech model
belongs_to :tech
end
Then you could search via something like:
search = Name::Tech.where("name LIKE :prefix", prefix: "word_start%")
.joins(:tech)
.order(usage_count: desc)
.limit(5)
This is starting point. It's fundamentally different from the gem, as each tag is just a string on its own, but references a richer data table on the back end. I'll work on implementing and come back to update with a better solution.
The auto_complete_for dealio from script.aculo.us is great an all, but is there a way for me to selectively disable the fact that it always auto-selects the first item in the list?
The problem is that, if I want to type my own entry that is new, and novel, I don't want the first item in the list to be auto-selected. The reason is because when I TAB out of the field, it selects, and fills the text box with that first item.
I got around that, somewhat, by making the first item in the list the same as what I'm typing, but that's not perfect either, because the auto_complete list doesn't always update with every keystroke, depending on how fast I type. I've tried setting the list refresh rate to the lowest value (1 millisecond) but no go.
What I really want is an option in "auto_complete_for" that doesn't select that first item at all - the same way that Google Instant doesn't automatically select the first suggested search phrase - you have to arrow-down to select one.
Maybe I can do this via an HTML option that I'm missing?
Looking at the source, there doesn't appear to be an option for that, but I bet if you changed line 284 of controls.js to this.index = -1; it would do what you want.
Otherwise, it might be time to look for a different autocomplete widget.
If your requirements are too far away from the available plugin, then I guess there is no point in tinkering around. Its best to write your own JS code.
You might want to consider this: https://github.com/laktek/jQuery-Smart-Auto-Complete
or this : https://github.com/reinh/jquery-autocomplete
I'll add another alternative that works great with Rails 3:
http://github.com/crowdint/rails3-jquery-autocomplete
I recently implemented auto complete for more than a field for Rails 2.0.2.
The plugin I used is:- https://github.com/david-kerins/auto_complete . Not sure if it supports Rails 3.
I have also encountered issues on implementing the above scenario and have posted questions( Implementing auto complete for more than one field in Rails ; Implementing a OnClick kind of functionality and formatting wrt Rails Partial-Views ) on stackoverflow for the same, I have been lucky on getting things working for me based on my requirement.
Kindly refer to these questions, they might have relevance to your requirement.