Unfortunately,
even simple database table files require special server side software
to read the stored information. Fortunately there is an alternative
to using server side databases.
Tables are simply text files with a numbered list of records separated
into fields using commas or tabs. This is called a two dimensional
array. In the JavaScript scripting language version 1.1 or higher,
it is an easy matter to construct a two dimensional array. Below is
an instance of a Javascript array. It is a sequentially numbered list
of variable names to which values are assigned. The array is constructed
using the JavaScript language written directly within the head tags
of a html web page. The code will look something like this:
var car = new Array()
car[0] = 'red'
car[1] = 'green'
car[2] = 'blue'
The line "var car = new Array()" creates an instance
of the "car" array. The subsequent lines populate the array with values.
Now, if we first create a function "car", and give it parameters and
name the parameters, we can start to build a more complex array which
will look like this:
function car(make,type,color){this make=make; this type=type;
this color=color}
var line = new Array
line[0] = new car('General Motors','4 door','red')
line[1] = new car('Ford','2 door','green')
line[2] = new car('Chrysler','coupe','blue')
That is all there is to creating a two dimensional database array
in JavaScript. It is an elegant method because it uses a minimum amount
of code and can be easily accessed from within a Web browser on the
client machine. For instance, to get the color of the Ford requires
the following simple line of code:
line[1].color
This code will return the value 'green'.
Notice how this array looks very much like a database table with rows
and columns. "line[n]" represents a record (row) while "color" is
a field name (column). This defined array is a JavaScript database
requiring no special server side software for access.
In the actual array for an e-commerce application there are 9 fields
which we define:
1. type This is a product subset of a product category.
2. desc A short description of the product.
3. price The current product price.
4. maker A three letter code to identify the maker of the product.
5. pid The product ID or inventory number.
6. state The state or country where the product is shipped
from.
7. special A three letter code to determine how a product is
taxed, how shipping costs are computed, and what detail message to
pop up.
8. itemwt The shipping weight of an item.
9. itemtax The tax rate for an item.
Not all fields are used in the current version of MyStore software.
They are, however, defined so current databases will be compatible
with future versions of the software.
Notice that the array size and the data type and size within a field
have not been specified. This is a nice feature of JavaScript array
databases. The array size is determined by the highest record number
used while the field type is a character string of any length.
Binary information such as an image file cannot be stored in a JavaScript
array. However, the name of the image or the file name for the image
can be stored. Since information in the array is always accessed from
an html web page, an image can be written to the page by using the
file name to form a link or reference to the image.
Another nice feature of the JavaScript array is its small footprint.
It takes about 100 Bytes to populate a record. The document within
which the array resides is normally about 1Kbyte; so, a JavaScript
database of 100 items will create a document of only about 11K.
This small size is important for two reasons: 1) It is always prudent
to keep files as small as possible from a storage and searchability
standpoint. 2) The small size allows the entire database to be transferred
over the internet in a short amount of time.
Now comes an important difference between client side e-commerce software
and server side software. In the server side scenario, when a customer
wants to view information on a particular product, a query goes out
to the server machine from the customers client machine. Based on
the request, the server machine generates an html page from specified
information in the server's database. The page is then sent to the
client machine for viewing by the customer. Each time the customer
selects a new product, the process is repeated.
In the client side scenario, when a customer wants information on
a particular product, a request is made to the server for the entire
JavaScript database for that product category. Upon receipt of the
database, the customer's computer generates a page for viewing. Whenever
the customer wants to view another product in the same category, the
information is extracted from the now resident database. Another internet
transaction is not required. This means an almost instantaneous response
to the customer's request and a tremendous reduction of server resources
and internet congestion.
About the Author:
Mel Davey is the creator of ImagineNation (http://imaginenation.com/),
a full service E-Commerce Application Service Provider, offering Storefronts,
Order Management Utilities, and 3rd party credit card processing.
|
| From
the Forum: |
| Paypal versus Credit Card |
I am currently using Apollo hosting for $20/month and part of the deal is that you can get free (no fixed cost) credit card processing via Authnet for about 3.5% and $.50 per transaction (starter package - prices drop with volume). All this for $20/month.
I thought about PayPal, but my personal experience is that I like the security of a credit card and with PayPal the customer has to set up the account (if they don't have one) which could cause the lose of a sale. ...
|
|
By
Mel Davey