ajax-chosen.coffee | |
|---|---|
do ($ = jQuery) ->
$.fn.ajaxChosen = (settings = {}, callback = ->) ->
defaultOptions =
minTermLength: 3
afterTypeDelay: 500
jsonTermKey: "term" | |
| This will come in handy later. | select = @
chosenXhr = null
|
| Merge options with defaults | options = $.extend {}, defaultOptions, settings |
| Load chosen. To make things clear, I have taken the liberty of using the .chzn-autoselect class to specify input elements we want to use with ajax autocomplete. | @chosen()
@each -> |
| Now that chosen is loaded normally, we can bootstrap it with our ajax autocomplete code. | $(@).next('.chzn-container')
.find(".search-field > input, .chzn-search > input")
.bind 'keyup', -> |
| This code will be executed every time the user types a letter into the input form that chosen has created | |
| Retrieve the current value of the input form | val = $.trim $(@).attr('value') |
| Depending on how much text the user has typed, let them know if they need to keep typing or if we are looking for their data | msg = if val.length < options.minTermLength then "Keep typing..." else "Looking for '" + val + "'"
select.next('.chzn-container').find('.no-results').text(msg)
|
| If input text has not changed ... do nothing | return false if val is $(@).data('prevVal') |
| Set the current search term so we don't execute the ajax call if the user hits a key that isn't an input letter/number/symbol | $(@).data('prevVal', val)
|
| At this point, we have a new term/query ... the old timer is no longer valid. Clear it. | |
| We delay searches by a small amount so that we don't flood the server with ajax requests. | clearTimeout(@timer) if @timer
|
| Some simple validation so we don't make excess ajax calls. I am assuming you don't want to perform a search with less than 3 characters. | return false if val.length < options.minTermLength
|
| This is a useful reference for later | field = $(@)
|
| Default term key is | options.data = {} if not options.data?
options.data[options.jsonTermKey] = val
|
| If the user provided an ajax success callback, store it so we can call it after our bootstrapping is finished. | success ?= options.success
|
| Create our own callback that will be executed when the ajax call is finished. | options.success = (data) -> |
| Exit if the data we're given is invalid | return if not data?
|
| Go through all of the | selected_values = []
select.find('option').each ->
if not $(@).is(":selected")
$(@).remove()
else
selected_values.push $(@).val() + "-" + $(@).text()
|
| Send the ajax results to the user callback so we can get an object of value => text pairs to inject as | items = callback data
|
| Iterate through the given data and inject the | $.each items, (value, text) ->
if $.inArray(value + "-" + text, selected_values) == -1
$("<option />")
.attr('value', value)
.html(text)
.appendTo(select)
|
| Tell chosen that the contents of the | select.trigger("liszt:updated")
|
| Finally, call the user supplied callback (if it exists) | success(data) if success? |
| For some reason, the contents of the input field get removed once you call trigger above. Often, this can be very annoying (and can make some searches impossible), so we add the value the user was typing back into the input field. | field.attr('value', val) |
| Because non-ajax Chosen isn't constantly re-building results, when it DOES rebuild results (during liszt:updated above, it clears the input search field before scaling it. This causes the input field width to be at it's minimum, which is about 25px. | |
| The proper way to fix this would be create a new method in chosen for rebuilding results without clearing the input field. Or to call Chosen.searchfieldscale() after resetting the value above. This isn't possible with the current state of Chosen. The quick fix is to simply reset the width of the field after we reset the value of the input text. | field.css('width','auto')
|
| Execute the ajax call to search for autocomplete data with a timer | @timer = setTimeout ->
chosenXhr.abort() if chosenXhr
chosenXhr = $.ajax(options)
, options.afterTypeDelay
|