I'm hopping this awesome community can steer me on the right direction. I came from the flash/flex/js world, and I like how simple it is to define an item renderer in flex. Here is what I'm trying to accomplish:
I have an Angular component which consist of a form and a html table. I have the columns, headers, rows, etc. all populating correctly using ng-repeat. I want to be able to define column "renderers", so if someone passes me a column property like "renderAs: 'button'" or "renderAs: 'progress'" I should be able to render the entire column as a button, or progress bar, etc.
Here is what I've tried so far:
ng-bind-html="getColRenderer(column.renderAs, column.value)" which
returns HTML based on 'renderAs'. As you all probably know, this
will only work with basic HTML stuff, but I cannot append an
'ng-click', or an 'href' due to angular's security. So, I opted
for something else.
I semi-have a good solution embedding a "ng-switch" inside my
ng-repeat. I had an ng-if but with several types of potential
"renderers" I opted for the switch. This somehow seems like future
problems while trying to display too many columns or rows, just my
fears.
Decorators - I like decorators, but it seemed a bit too much for
something as a simple button that calls something on click or a
progress bar with 2 values. So, I halted going into this path, but
if this is the shinning path all walk, then by all means.
I hope someone out there has ran/done something like this and can steer me on the right course of action. If the ng-switch or ng-if is okay, then I'm good to go.
Once again, thank you in advanced.
Related
I've read everything I can on forms and such and they never seem to work the way I want them to.
As a work around, I'm trying to pass a series of parameters to my controller via remote: true and javascript. I've got a solid foundation working.
I can't think of a proper way to explain this without getting too crazy, so I'll just explain what I am doing.
Goal-
I have a FlashCard model going. The flash cards each have: Title, lines(7) and a body. The body is represented as the back of the card. The front of the card consists of the title and 7 lines. Each line can be written on individually and optionally centered. The card can be formatted as either read or write. Obviously read is a read-only and write gives you the ability to change whether or not each line is centered, and change/add the text on the title, each line, and the body.
Now. I probably chose a bad way to do this, but it's how I chose to do it. I have an affinity towards arrays so I tend to use those when in doubt.
My flash card model has title:string, line:string as array, and body:text.
The line is formatted as follows: [["",0],["",0],["",0],["",0],["",0],["",0],["",0]]
The strings are the string on each line and the 0's can be either 0 or 1, as false and true- representing whether or not the text on that line is centered.
As far as displaying all of this, I have it working just fine. However- actually saving the data is proving to be a problem. Forms are not working out for me because of the line array/attribute. I don't mind doing the logic myself without the form, but I need a way to pass the data from the text_fields to the controller to save them.
Hopefully that makes sense. If not- I will happily add in the code I have used to get to where I am and more specifically show where I am having problems.
Optimally, I would like to simply pass the strings from multiple text_fields as separate parameters to the controller. If necessary to go back and entirely redo the model, I will do so if it will work as long as I can get the same functionality.
Thanks in advance for the help!
Angular newb here, thoughts appreciated...
Say I want an input field to control the window title as you type. A field with a model binding and no associated controller acts on keypress, as intended. However, there has to be a bit more logic to it -- default value before any user input, also used if the input is blanked.
Adding a controller bound to enclosing elements gives a place for that logic, but the change-on-keypress behavior is gone. I'm sure it's possible to recreate it by hand or with ui, but since it's inherently there without the controller, I'm wondering if I'm missing the simple clean way.
Simple version, acts on keypress, but with no smarts:
<title ng-bind-template="{{windowTitle}}">Default Title (not seen)</title>
<input ng-model="windowTitle" type="text">
Putting controller bindings on the head (for the title) and a containing div (for the input), and setting a default $scope.windowTitle inside the controller function does use that default value, but it breaks the auto-update.
I know in real life you'd want a real model, but what I'm really trying to understand is these two ways angular appears to work. I haven't found anything specifically describing two different implicit input binding behaviors, but I haven't been through all the docs yet.
How should I be thinking about this?
Edit: It's not the window title or default value per se that I'm interested in. I'm trying to understand this:
When there's no controller on either the field or the title, typing in the field changes the window title immediately, on keypress. The title is directly linked to the field value, with no other angular hookup.
With controller bindings around the title and the field, typing in the field has no effect on the title.
What I've since realized (I think) is that ng-controller bindings create a new instance of the controller each time. Here's the non-working code I didn't show before:
<title ng-controller="TitleCtrl" ng-bind-template="{{windowTitle || 'Foo'}}">Foo</title>
...
<label ng-controller="TitleCtrl">
<input ng-model="windowTitle" type="text">
{{windowTitle}}
</label>
The value set by the model binding to the field is shown correctly within that instance of that controller, and updates on keypress, as before. But since those two controller instances are separate, the binding to the title works but the data it points to isn't bound to the field.
Isn't that right? The reason it works with no controllers is that that makes the value global, so the title binding sees the value set by the field binding.
So what's the canonical way to reference data from some other area? Create a service?
I realize that this is basic angular stuff, just getting started here, so thanks!
Edit 2
On reflection, I've come to seriously disrespect this whole question, even though I wrote it.
It's based on way-too-early poor understanding of the Angular application model. I had worked through only part of the official tutorials, and jumped ahead to removing all the js from a not big but not totally trivial existing app, and exploring what Angular could to in that context.
I got some very quick bang for the buck, getting several pieces of functionality working with very little code, and simple, clear markup, felt good. But I really had short-circuited internalizing the Angular way of thinking, and my quick and dirty no-architecture approach broke down when different parts of the page needed to coordinate with each other, as in this question.
I've postponed that project while I go back to tutorials and other learning. If other folks think this question should be deleted, I'd add my vote. Or maybe it's a useful on some level, ignorant though it is.
Well, there are multiple ways to achieve the behavior you want without using an explicit controller and model, you could:
<title ng-bind-template="{{windowTitle && windowTitle || 'default'}}"></title>
Or in a more simple way:
<title>{{windowTitle && windowTitle || 'default' }}</title>
In both cases, we're using the conditional expression:
(condition) && (answer if true) || (answer if false)
You should however strive to remove logic from the templates.
This is my most confused aspect that I continually have to ask people about. They have given me answers like 'if it works with data it goes in the model'... but to me that is pretty much ALL of it.
Does anyone have a better way to explain this?
Perfect example from my current code:
I have a listing of posts that can be favorited or not favorited. On the front end, i differentiate the different ones by dynamically adding class="favorite" to the HTML depending on if its a favorite or not.
So basically ... <li class="item<%= is_favorite?(current_user.id) %>">
Part of me thinks this should go in the model because its going to be running a statement to find a record that matches :resource_id and :user_id...
but another part of me thinks its going to be in the controller because its directly outputting the word " favorite" which is used in html
My second mini question is, is it the-rails-way to put methods that the controller uses in the same controller? as long as they remain un-routed, etc. Or is that not the right spot?
You're thinking properly.
The right answer is that you should use presenters or decorators.
See this railscast for inspiration.
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.