Drop down boxes

[NoeticCC]

Re: Drop down boxes

I will study this later. Thanks so much!

I do hope I haven't confused you more than necessary - but I do remember that time, about 5 months ago, when I first looked at WAS components and, intuitively, kept trying to edit the Xbasic and HTML tabs to get what I wanted, and kept thinking programming directly in an a5w page was impossibly hard...

... funnily enough, it was the AJAX libraries that really kicked me into getting to grips with Xbasic in A5w pages, because I remember from ages back when I tried to adapt (successfully, but still had no clue what I was doing!) a bunch of drag & drop javascript libraries, what a major PAIN it is to code in Javascript! ;)

[martin horzempa]

Re: Drop down boxes

Hi Martin,

Where do you put the code? Does it go in the a5w page, or in the html tab of the component?

Thanks!

Gary

Hi Gary - sorry about the delay - been busy today
the code goes in the A5w page

btw in this instance you will not need to use the Tilde "`" as you will not be
parsing a string to extract the seperate data elements

as to speed - Ajax vs Javascript
there is really nothing magical about javascipt or ajax
if you need data to populate a dropdown both cases require
that data be fetched from the database and then sent to the client
browser, with javascript is is done when the page is loaded so it is faster if you dont include the extra time required to load the page

which should you use - that would depend on your needs

if you have a small number of items for your dropdown list then
it would seem better to use javascript - if you dont mind doing a little coding
if on the other hand your data might include several thousand items
then it would make more sense to use ajax and filter the data on the fly

both cases can be dynamic (from a table) or could be hard coded
and both could be filtered ( javascript on the page and ajax on the server)


1st i really dont want to get crosswise with Andrea -
if you want todo this using the Ajax functions then fire away Andea will be great help
if you want me to lend a hand with the javascript i will be happy to
just let me know

[NoeticCC]

Re: Drop down boxes

as to speed - Ajax vs Javascript
there is really nothing magical about javascipt or ajax
if you need data to populate a dropdown both cases require
that data be fetched from the database and then sent to the client
browser, with javascript is is done when the page is loaded so it is faster if you dont include the extra time required to load the page

TBH AJAX uses Javascript just as much - the difference is plain Javascript requires the values that are filled into the other boxes to be pre-loaded*, which makes them visible in the page source, and makes the initial page load slower (depending on how much data is retrieved).

* The same effect could probably be achieved by pre-loading the detail section data in a grid

[martin horzempa]

Re: Drop down boxes

TBH AJAX uses Javascript just as much - the difference is plain Javascript requires the values that are filled into the other boxes to be pre-loaded*, which makes them visible in the page source, and makes the initial page load slower (depending on how much data is retrieved).

* The same effect could probably be achieved by pre-loading the detail section data in a grif

we agree

with javascript is is done when the page is loaded so it is faster if you dont include the extra time required to load the page

[NoeticCC]

Re: Drop down boxes

we agree

My point was though, that the J in AJAX stands for Javascript (the Ajax libraries in Alpha5V9 mean you can use Xbasic to generate the response, which is easier esp. if you have some Xbasic experience but not JS experience)...

BOTH use Javascript to put data into the textboxes etc. in response to an event on the page.

The big difference is that with AJAX you can do anything from huge database queries to file/directory scans etc. etc. dynamically WITHOUT having to load all the information needed [for every single record you could select from this dropdown] when the page is first loaded.

When you just have a small handful of choices, and a handful of fields to be filled in, there's no reason to use AJAX, but if you have a database with thousands of records, it is MUCH faster to only retrieve the detail info when requested, rather than having to pull up and store (within the page) every field from various tables that you may or may not need to use to fill into fields on the page (depending on which selection is made).

[martin horzempa]

Re: Drop down boxes

My point was though, that the J in AJAX stands for Javascript (the Ajax libraries in Alpha5V9 mean you can use Xbasic to generate the response, which is easier esp. if you have some Xbasic experience but not JS experience)...

BOTH use Javascript to put data into the textboxes etc. in response to an event on the page.

The big difference is that with AJAX you can do anything from huge database queries to file/directory scans etc. etc. dynamically WITHOUT having to load all the information needed [for every single record you could select from this dropdown] when the page is first loaded.

When you just have a small handful of choices, and a handful of fields to be filled in, there's no reason to use AJAX, but if you have a database with thousands of records, it is MUCH faster to only retrieve the detail info when requested, rather than having to pull up and store (within the page) every field from various tables that you may or may not need to use to fill into fields on the page (depending on which selection is made).

again we agree

which should you use - that would depend on your needs

if you have a small number of items for your dropdown list then
it would seem better to use javascript - if you dont mind doing a little coding
if on the other hand your data might include several thousand items
then it would make more sense to use ajax and filter the data on the fly

UNCLE!!!! UNCLE!!!!
no argument here Andea, in fact you are restating my post
i really didnt want to step on your toes - nor did i mean to
my only point was
if Gary wants a little help with the javascipt i'll be happy to lend a hand
if he would rather do it using the Ajax functions then your his gal

[NoeticCC]

Re: Drop down boxes

again we agree

Curious - who is "we"? :)

UNCLE!!!! UNCLE!!!!

Auntie? :p

no argument here Andea, in fact you are restating my post
i really didnt want to step on your toes

No stepping on toes at all... just wanted to point out that AJAX basically uses Javascript all the same as Javascript in an .a5w or .htm(l) page does...

It just lets you use Xbasic (in the filename.AJAX.a5w pages), which more experienced Alpha developers may be more well-versed in, and which most definitely is easier to handle than JS!, to manipulate the elements on the page, instead of having to hand-code everything and having to pre-load every possible value you may eed to use in the Javascripts.

(I just remember *my* initial confusion with trying to put Javascript into the HTM component etc. of the web components in Alpha 5....)

[martin horzempa]

Re: Drop down boxes

thats why i offered to help

[drgarytraub]

Re: Drop down boxes

I really, really appreciate the help that the two of you have given and are willing to continue to provide. I just cannot thank you enough.

Now, I really would like to learn both approaches because each would be useful in all kinds of situations.

Right now though I would like to start with the approach that makes the most sense for my particular situation. I want a drop down that shows the following:

Patient ID PtType Status

I would like the display to be wider than the field if possible so that all 4 columns are easily seen, and also have the columns and data below them to be evenly spaced. Then, when the user selects a choice, there are 16 fields to be automatically filled in. The number of patients is presently several hundred but needs to be able to handle thousands in the future.

With this information, what would be the best way to proceed?

And again, I thank you both for your generous time and guidance!

Gary

[martin horzempa]

Re: Drop down boxes

hi Gary

The number of patients is presently several hundred but needs to be able to handle thousands in the future.

as you can tell from the discussion above
your requirements indicate that you should be using the ajax functions and not simple javascript
this will give you a page that loads quickly and will be
extremely responsive with thousands of records

so i will leave you in the competent hands of Andrea
if you have a need for the other technique in the future
i'll still be happy to help

[drgarytraub]

Re: Drop down boxes

Good morning Andrea,

Could you please guide me on the specifics of using AJAX to accomplish what I described. The name of the field that I want the drop down for is PATIENT and it is in a Grid called Patient_new.

When the user clicks the arrow icon, the drop down should display patients in alphabetical order, but also show 3 other coluns, with the data neatly aligned in each column.

When the user then clicks on the patient they want, the patient field should fill in with their selection, as well as 13 other fields.

If you could tell me the specific of how to implement this, I would be so grateful.

Gary

[NoeticCC]

Re: Drop down boxes

Good morning Andrea,

Could you please guide me on the specifics of using AJAX to accomplish what I described. The name of the field that I want the drop down for is PATIENT and it is in a Grid called Patient_new.

When the user clicks the arrow icon, the drop down should display patients in alphabetical order, but also show 3 other coluns, with the data neatly aligned in each column.

When the user then clicks on the patient they want, the patient field should fill in with their selection, as well as 13 other fields.

If you could tell me the specific of how to implement this, I would be so grateful.

Gary

Hi,

Sorry I've been off for a few days, will see if I can put together a demo ASAP but I'm a bit busy at the moment. I do believe Alpha have a copy of a sample I did and are looking to include this & an AJAX-based file uploader in one of the next releases (in the web app samples).

[drgarytraub]

Re: Drop down boxes

Hi Martin and Andrea,

Actually, I have thought more about the situation, and I think java script is the way to go for several reasons.

For one thing, the actual number of entries will never exceed several hundred and could be limited to 10, 20, 30, 50 or something like that. The situation is that when the user clicks on the arrow for the drop down, I want to display the current patient's most recent 20 or so appointments. The user then clicks on one of those and the fields on the appointment form are automatically filled in. So the drop down will not ever contain thousands - the table will contain thousands, but the drop down will be filtered to show only that patient's most recent appointments.

With this said, could you please guide me through this process?

Gary

[NoeticCC]

Re: Drop down boxes

Actually, I have thought more about the situation, and I think java script is the way to go for several reasons.

The J in AJAX stands for javascript...

The problem with JUST using Javascript is that you would have to retrieve every single piece of data you want to fill into the other fields when the page first loads, whereas if you use the built-in AJAX libraries you only pull up what is needed.

How many fields do you want to fill then? And to what purpose are you pulling up this data?

One thing you might want to look into is creating a grid, showing just one record, and using the QuickSearch option (with a dropdown) as shown in the quicksearch example of the web app samples included with Alpha5: http://www.charlesworth.biz/WAS/quicksearch_page.a5w

[drgarytraub]

Re: Drop down boxes

Hi Andrea,

Thanks again for your response.

I understand that the the J in AJAX stands for JavaScript, and that AJAX is implemented via JavaScript. I should have clarified this before, so let me explain. Apparently, not all browsers (e.g., pda's) work that great with complex javascript, or at least with some aspects of javascript, and it appears that the http request function is one of those situations. Thus, I am trying to stay with the most basic of javascript.

As far as the pre-loading issue, I need to fill approx 10 to say 14 fields, and I would be content with the drop down showing just say 4 or 5 columns with perhaps 20 to 30 records. I am not sure, but I think that would not be a major hit on speed - I could be completely wrong on this, but what do you think, given the additional details I have just provided?

In regard to your last paragraph, I am not sure I understand how that would solve this problem - could you explain a bit further ...

Thanks again for offering your insights and help - it is greatly appreciated!

By the way, regardless of what turns out to be the best way to go on this, simple javascript or ajax, I (and I am sure others) would really like to learn both methods.

Gary