This is probably jquery basics, but I can't find a solution after much googling.
How do you attach "non-events" to elements inserted in the DOM?
For events, like click, we can use live() or bind().
How would you, for instance, initialize tabs() or addClass() to a new element?
Specifically, I'm trying to get tabs() to work in the content of an ajax loaded dialog, but I think the correct solution should be applicable to any situation.
I did see a trick that involved $('body').mousemove() which did work, but that is still binding to an event and obviously a hack.
For instance, how would you get addClass() to fire on a newly inserted table row?
I mean to do this implicitly, meaning that I don't want to write out specific instructions for every event that adds nodes to the dom, I just want it to "run in the background".
Let me know if this needs clarification, I see many similar questions on SO but no answers that have helped.
EDIT: Simple example: A page calls $('a').addClass('highlight') which works on all anchors in the page. A new anchor is then added to the page dynamically by jQuery, but does not get the class added.
EDIT: I have tried all kinds of bind(), trigger() and change() methods but I'm afraid I'm barking up the wrong tree.
you need to look at livequery it will allow you to apply things to newly added elements
also if your adding the element you can do
$('body')append('<div>some content</div>').tabs();
or something like that
I know that I may contradicting your "non-event" rule here, but just by saying that you want something "triggered", you're already implying some kind of event.
In that case, may I suggest jQuery custom events? You may want to create a custom event, then trigger it manually somewhere in your code. It's not automatic (like when you add a row, BOOM, it fires™), but that's the closest thing I can think of with what you were describing.
Specifically, you may want to look at jQuery's .bind() and .trigger() methods.
Related
I'm using ui-grid 3.2.1.
Trying for a long time now to find an event that notifies me when rows are rendered in the DOM.
I looked a lot in SO, and in their issues in Github.
My test to see if rows are rendered is basically $('.ui-grid-row').length > 0.
I tried rowsRendered event, modifyRows(data), all sorts of $timeout(0) in almost every spot I could, nothing worked, all callbacks are called when the above jQuery still doesn't have results.
As a last resort I found a very inefficient solution - I $watch the .html() changes of .ui-grid-contents-wrapper, which contains the .ui-grid-row elements, and when I find one, I turn off the watcher and call the callback. It's bad but it works.
Note - The rows/columns somtimes contain inner directives which may take some time to render. I don't think it should influence rowsRendered() event.
Please, can anybody help with this?
No support from ui-grid team sadly.
EDIT:
plunkr that show there are no .ui-grid-row in DOM when rowsRendered() is called:
https://plnkr.co/edit/8clwC5hkwhAEjvoLZ6vO?p=preview
Try
var rows= gridApi.core.getAllVisibleRows(gridApi.grid);
inside rowsRendered function.
I'm looking for an event fired by polymer-layout when it's finished laying out, similar to the polymer-grid-layout event. Doesn't seem to be one. Am I missing something?
After my attempts at polymer-grid-layout (Autosizing canvas inside a polymer grid layout) I've decided to convert everything to nested polymer-layouts instead. After a few hiccups (e.g. the dart version of polymer-layout doesn't work if you put polymer-layout as an element directly under template, whereas the js version does - don't know which is wrong) the approach seems to be working.
The one exception is that I was previously relying on polymer-grid-layout to tell me when the canvas had been resized properly. But with polymer-layout I have the same timing problem but without the same solution it appears.
Any way around this?
thanks
Anders
Dart polymer_element/polymer_ui_element are a bit outdated. I'll take a look at what changes were be made in JS polymer-layout since I last revisited Dart polymer-layout (probably Mo/Di).
Can you please create an issue in https://github.com/ErikGrimes/polymer_elements so you get notified when the update is made.
You are right that polymer-layout is missing a layout event. I filed an issue here https://github.com/Polymer/polymer-layout/issues/3
In the meantime, you should be able to capture the timeline in attached.
attached: function() {
this.async(function() {
this.async(this.layoutHappened);
});
},
layoutHappened: function() {
}
I used nested async because I don't want to worry about whose attached is called first (this one, or the one in the polymer-layout). And yes, this is exactly the kind of fiddly construction that is avoided by having an event.
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.
In my layout, I'm calling include_javascripts() in my <head></head> section. Later on in my layout, I'm calling a component which makes use of use_javascript(), but, unfortunately, the javascript has been output, so this request falls on deaf ears.
I can think of a few approaches:
Put the call to `include_javascripts()` at the bottom.
At the moment I can't do this, because I'm using a CMS on top of symfony which uses a lot of inline javascript.
Override the include_javascript helper, or create a new one, which adds doesn't add anything, but adds it adds to a queue that a filter will take care of after rendering the page.
This is sort of like the common filter which was removed from 1.2. Obviously, they don't seem to like this approach.
Are there any other alternatives?
The use_javascript function simply adds the specified script to a collection, which is output by the include_javascripts function.
In order to have inline javascript in your code, you will need to use tags, since the use_javascript is pointless unless include_javascripts is called afterwards.
If you do not want to deal with filenames and such, you could always use sfConfig::get('sf_root_dir') . js/filename.js to grab your file.