Opening Tag | Meaning | Closing Tag | Meaning | |
<FORM> | Start of a Form | </FORM> | End the Form | |
(Required: ACTION ="file" METHOD = "post" Calls "file" when submitted, sending data via "post") | ||||
<SELECT NAME = "var"> | Start of Selection List | </SELECT> | End of Selection List | |
<OPTION> | Start of Option (one can be SELECTED) | </OPTION> | End of Option | |
<TEXTAREA> | Start of a Text Input Area | </TEXTAREA> | End of Text Area |
| |
---|---|
<INPUT TYPE = "text" NAME = "var" > | Input Text Area, can also specify SIZE, MAXLENGTH, and VALUE |
<INPUT TYPE = "radio" NAME = "var" VALUE = "txt"> | On/off radio button, only one option with same NAME allowed. |
<INPUT TYPE = "checkbox" NAME = "var" VALUE ="txt" > | Input multiple options, only checked items sent |
<INPUT TYPE = "password" NAME = "var" > | Text Input but characters are not displayed. Data is not encrypted. |
<INPUT TYPE = "hidden" NAME = "var" VALUE = "txt" > | Method used to pass data to server that is not displayed on form. |
<INPUT TYPE = "file" ACCEPT = "type" NAME = "var" > | Allow users to upload files of certain type. Accompanied by "browse" feature. |
<INPUT TYPE = "submit" VALUE = "label" > | Sends data to file specified in "ACTION" field of FORM tag. |
<INPUT TYPE = "reset" VALUE = "label" > | Clears all form data and restores initial values |
<HTML> <BODY BGCOLOR = "#FFFFFF"> <H1> A Simple Form </H1> <FORM ACTION = "process1.php3" METHOD = "post"> Enter Your Name: <INPUT TYPE = "text" NAME = "student"> <BR> Select Your Grade Level: <SELECT NAME = "grade"> <OPTION SELECTED > 12 <OPTION> 11 <OPTION> 10 <OPTION> 9 </SELECT> <BR> <INPUT TYPE="submit" VALUE = "Submit"> <INPUT TYPE="reset" VALUE = "Clear"> </BODY> </HTML>
The web server needs to recognize that there are PHP enhancements to an HTML file, so the extender at the end of the filename is ".php3" instead of ".html" as we have had before. The specialized PHP code is inserted between two new tags, "<?" and "?>". Within those tags, the values of any variables passed to the web page from the form are easily accessed.
Notice that the variable names are the same as defined in the form, but are preceded by a dollar sign ($). In fact all scalar type variables in PHP are preceeded by a dollar sign, which is very similar to Perl. For instance in the simple program form1.html , the INPUT TEXT variable was called "student", so we can now refernce the value entered by the use with the PHP variable "$student". The SELECT variable had a name "grade", so we now reference the value selected as "$grade". There is also a simple calculation using a new variable "$graduate" that figures out when that student will graduate. The calculation we make is like code very similar to standard programming languages like C or C++. In fact, most standard programming constructs found in C++ exist in PHP, too.
For the web browser to display anything while in the PHP portion of the
document, the information must be included as part of a print statement.
This includes any HTML tags desired for formatting purposes.
Take a look at the simple PHP program below that processes the data sent
by the form program, and then run the program to actually see it work.
<HTML>
<BODY BGCOLOR = "#FFFFFF">
<H1> Processing the Form </H1>
<?
print("Hi $student! <BR>");
print("You are in grade $grade. <BR>");
$graduate = 2001 + (12 - $grade);
print("You will graduate in the year $graduate.");
?>
</BODY>
</HTML>