Booking Calendar

[nvening]

Hi, I am looking to create a calendar where I the user can select one or multiple dates for booking. Dependant on what dates and how many the user selects the price is worked out etc. Also already booked dates would be shown so they cannot be selected

I'm sure there are scripts like this available but I would like to use this situation to learn some JavaScript - I think this is the best language to use? I am already competent in HTML/CSS.

So JavaScript on the front end accessing a mysql database, is this the standard method of working JavaScript aps? I think this type of thing is know as AJAX?

Anyway, I just wanted to ask for some guidance as to what to look into and how the app could work.

Cheers, Neil

[scaryjim]

Javascript isn't really designed for accessing and updating databases - it's designed for creating a more dynamic and interactive experience on a web page. Javascript on its own can't retrieve data from your database - it needs some other serverside technology to process and output the data. Ajax does this on the client side by sending a request to a web server for some information, however the server has to respond with appropriately formatted data - i.e. some kind of text stream. To acheive that you'll need scripts on your server that can access your database, retrieve the necessary information, then format it appropriately for your ajax script to handle.

However, your serverside scripts could also access the database then format the data into a new HTML page that is returned to the server - this is how most web apps work, and is also the way HTTP is *designed* to work: when the user fills out an HTML form and hits the submit button, their browser seonds all the input they've made to the web server, and expects to get a web page in reply. Ajax uses (abuses?) the fact that HTTP doesn't actually care whether you send HTML, XML, or any other format of data to give the impression of a user using a "normal" application, but it is essentially a trick.

Anyway, you'd need serverside scripting in php, perl, ASP.NET or any of a wide variety of other languages, which would retrieve your data from the database. You would then either build this into dynamic web pages on the server and return this web page to the user, or format the data as XML and use an AJAX technology in a static webpage to retrieve and display the data. Ideally, if you're using ajax you'd also set up the app so it can work without javascript, and there are some clever tricks for doing this.

In the first instance, however, I'd strongly recommend going down the "classic" route (i.e. using ordinary forms and doing all the processing on the server) as it means only one set of coding (serverside language to create a dynamic web page) rather than two (serverside language to create an XML feed, plus AJAX to handle the data on the web page).

[nvening]

Ah thats really helpful thanks, its given me more of an idea and pointed me in the right direction!

I think ill follow your advice and create a basic form based version of the concept linked up to a mysql database via php. Then ill ajax it up *coined* later on. I know its not necessary to use Ajax for this project but its something i definitely want to learn how to implement it.

Neil

[peterb]

The 'standard' server-side scripting language to access mysql databases is php. (V-bulletin - which hosts Hexus is a php application running on top of a mysql database - so it is pretty scaleable. There are many other PHP apps around, Wordpress for example. If you haven't looked at php for retreiving (and writing) data to a mysql databqase, it might be worth spending a little time looking at it to see if it meets your requirements.

[nvening]

Im familiar with php/mysql I just wanted to use ajax to so that no page refreshes were needed, thus enabling the user to quickly and easily change their selection and choose what dates are the best for them depending on price etc

Cheers, Neil

[peterb]

Ah - I see - a sort of 'auto-refresh' whenever a change is made by the user.