> On Jun 23, 2019, at 12:22 PM, Chris Sansom <chris57.san...@gmail.com> wrote:
>
> Hi Walter
>
> Thanks for your long and thoughtful response… some of which I understood! (I
> did say I was rusty, and I was never extremely advanced - never got into OOP
> for instance unless it was laid out on a plate for me as prototype does).
>
> Just a quick question - do you know whether there’s some limit to the length
> of a string that can be returned via Ajax, and whether it can contain
> carriage returns, tabs or whatever? What I’m returning here is politely
> formatted and indented html with 76 options in the select.
Yup. That will stop a JavaScript insertion like you want to do cold. Try
replacing all of the newlines [and carriage returns, if any] with a single
space before you pass that value back to the Ajax request. It doesn't matter
how long the line is, as long as it's one line. I generally substitute
/[\n\r]+/ with ' '.
Walter
>
>> On 23 Jun 2019, at 16:09, Walter Lee Davis <wa...@wdstudio.com> wrote:
>>
>> One of the best ways to work this out is to build a cut-down example, in one
>> page, that tries to do what you're after here. If you can get that to fail,
>> post it as a Gist or similar. From your description, you're going about
>> things the right way.
>>
>> One other piece of advice. Rather than using a numerical index to get the
>> first of some collection, try making your method iterate over the found
>> results and operate conditionally. This will give you another place to put
>> console.log statements to further refine exactly what is going on inside:
>>
>>> var newhtml = xml.getElementsByTagName('newhtml')[0].firstChild.nodeValue;
>>
>> When you say that the correct code to insert is there in the Ajax response,
>> that cuts that part of the problem out, and your example page can just do
>> something dumb like this:
>>
>> var data_to_insert = $('some_example_element').remove().innerHTML.toString();
>>
>> ...where you have a DOM element like <div id="some_example_element"><select
>> ... your element here ...></div>
>>
>> I have found over the years that when you have the correct element (legally
>> possible to insert into a given container), then Prototype (and the browser)
>> just does what you'd expect. But if what you are getting back from the
>> server doesn't make any sense in terms of your DOCTYPE (say you are trying
>> to insert raw text into a <ul>, rather than trying to insert a <li>, then
>> the browser will just ignore you. It's not a Prototype error, in other
>> words, just the browser being pedantic when being called in a JS update
>> mode.
>>
>> Finally, see if you can get your server to return the HTML of the picker,
>> fully rendered. Then you should be able to do this:
>>
>> new Ajax.updater('parent_element_id', '/server/url', {
>> parameters: { foo: 'bar', ...}, // optional, pass to your server some
>> parameters
>> insertion: 'bottom' // this lets you put the rendered element at the bottom
>> of the existing children of the parent
>> });
>>
>> If #parent_element_id is a <li>, then the HTML you get from
>> /server/url?foo=bar should be:
>>
>> <li>
>> <select ... >
>> <option ...></option>
>> </select>
>> </li>
>>
>> ... with all of the whitespace removed.
>>
>> Walter
>>
>>> On Jun 22, 2019, at 11:25 AM, Chris Sansom <ch...@highway57.co.uk> wrote:
>>>
>>> With apologies in advance for the length...
>>>
>>> I retired a few years ago from web development, where I used Prototype
>>> quite a bit in the later years. I'm somewhat rusty now, but I'm trying to
>>> do some development for purely personal use. It won't be on the open web,
>>> just on our local server. It's all been going fine (if slowly!), but now
>>> I've hit a brick wall with Ajax.
>>>
>>> Here's what I'm trying to do:
>>> * I have a form with one or more <select>s, each within its own <li>, all
>>> in the one <ul>.
>>> * Each <select> contains the same list of items from a table in a MySQL
>>> database.
>>> * The last <select> has nothing selected and has the class "addselect".
>>> * The idea is that if I select something from that last <select>, an
>>> onChange event is triggered which calls an Ajax script to add a new
>>> <select> (containing the same items). This is set up on page load in a
>>> "document.observe ('dom:loaded', function()..." at the top of the
>>> javascript file.
>>> * Each <select> has a sequential name and id, eg 'name="country[0]"
>>> id="country_0"', the next country[1] and country_1, and so on. The newly
>>> created <select> would have the next name and id in sequence.
>>> I hope that all makes some sense.
>>>
>>> So...
>>> The handler function set up in 'dom:loaded...' gets the next index number
>>> for the name and id of the new <select>, and sends this ('entryindex') and
>>> the name of the table to search ('list') to the Ajax script, and off we go:
>>>
>>> var pars = 'list=' + list + '&entryindex=' + newIndex;
>>> var url = base + 'ajaxgetmenu';
>>>
>>> // send request to do the business
>>> var myAjax = new Ajax.Request (url, {
>>> method: 'post',
>>> parameters: pars,
>>> onSuccess: function (req) {
>>> var xml = req.responseText;
>>> ...
>>>
>>> This far, everything is hunkydory. Safari's Web Inspector shows exactly the
>>> correct result - a nice new <select> with the correct name and contents -
>>> under 'XHRs' in its Resources tab. So I know the script is being called and
>>> is operating correctly. But where it falls over is with what comes next:
>>>
>>> var newhtml =
>>> xml.getElementsByTagName('newhtml')[0].firstChild.nodeValue;
>>>
>>> This, incidentally, is taken from a script I developed back in my
>>> professional days which I know worked perfectly. But something is failing
>>> here, cuz it don't work! If I put an alert in ('ok') before this line, it
>>> pops up, but if I put it after this line it doesn't. And yet no errors are
>>> reported. And of course the next line doesn't work either:
>>>
>>> $('thisid').up('ul').insert (newhtml);
>>>
>>> (And I know "$('thisid')" is right because I put that in an alert to check
>>> it.)
>>>
>>> So I simplified it. I abandoned XML and made the result plain text instead,
>>> to be inserted verbatim. Again, the script produces a perfect result in
>>> Safari's Web Inspector, but even when newhtml is plain text (and I skip the
>>> xml.getElementsByTagName line altogether), it fails. And again, an alert
>>> before the insert line works, but not one after it.
>>>
>>> I've tried everything I can think of, so if anyone has any wisdom on this
>>> I'd be very grateful indeed. It's probably something dead obvious staring
>>> me in the face...
>>>
>>> --
>>> You received this message because you are subscribed to the Google Groups
>>> "Prototype & script.aculo.us" group.
>>> To unsubscribe from this group and stop receiving emails from it, send an
>>> email to prototype-scriptaculous+unsubscr...@googlegroups.com.
>>> To post to this group, send email to
>>> prototype-scriptaculous@googlegroups.com.
>>> Visit this group at https://groups.google.com/group/prototype-scriptaculous.
>>> To view this discussion on the web visit
>>> https://groups.google.com/d/msgid/prototype-scriptaculous/fb84d882-af7d-45f8-a400-b98701228f19%40googlegroups.com.
>>> For more options, visit https://groups.google.com/d/optout.
>>
>> --
>> You received this message because you are subscribed to a topic in the
>> Google Groups "Prototype & script.aculo.us" group.
>> To unsubscribe from this topic, visit
>> https://groups.google.com/d/topic/prototype-scriptaculous/CFLnDmlHmhM/unsubscribe.
>> To unsubscribe from this group and all its topics, send an email to
>> prototype-scriptaculous+unsubscr...@googlegroups.com.
>> To post to this group, send email to
>> prototype-scriptaculous@googlegroups.com.
>> Visit this group at https://groups.google.com/group/prototype-scriptaculous.
>> To view this discussion on the web visit
>> https://groups.google.com/d/msgid/prototype-scriptaculous/586F2AE6-E77E-4ECC-B18A-F1D80C04685A%40wdstudio.com.
>> For more options, visit https://groups.google.com/d/optout.
>
> --
> Cheers... Chris
> Chris Sansom: composer and… whatnot
> http://www.chrissansom.net/
> https://www.youtube.com/channel/UCVUKb7vK0KiIaiLhs7zht2Q
> https://soundcloud.com/mfthoad
>
> I got rid of my vacuum cleaner - it was only gathering dust.
> — Tim Vine
>
> --
> You received this message because you are subscribed to the Google Groups
> "Prototype & script.aculo.us" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to prototype-scriptaculous+unsubscr...@googlegroups.com.
> To post to this group, send email to prototype-scriptaculous@googlegroups.com.
> Visit this group at https://groups.google.com/group/prototype-scriptaculous.
> To view this discussion on the web visit
> https://groups.google.com/d/msgid/prototype-scriptaculous/845B17E5-CF17-408D-AB00-5F4C827F8260%40gmail.com.
> For more options, visit https://groups.google.com/d/optout.
--
You received this message because you are subscribed to the Google Groups
"Prototype & script.aculo.us" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to prototype-scriptaculous+unsubscr...@googlegroups.com.
To post to this group, send email to prototype-scriptaculous@googlegroups.com.
Visit this group at https://groups.google.com/group/prototype-scriptaculous.
To view this discussion on the web visit
https://groups.google.com/d/msgid/prototype-scriptaculous/688D6420-D57D-4C72-96AA-2C4E0129D984%40wdstudio.com.
For more options, visit https://groups.google.com/d/optout.
