Web Publishing with PHP and FileMaker 9- P8 docx

This line creates a FileMaker connection object for a particular user esmith with pass-word m4rg0t to a particular FileMaker file Product Catalog on a particular FileMaker Server machine

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Viewing FileMaker Data

As I see it, there is a big difference between allowing someone to view your data, and

allowing someone to edit or delete your data Viewing data is typically referred to as a

read operation, whereas editing or deleting data is called a write operation.

Beyond the obvious differences—for example, you don’t want random people deleting

your product catalog—there are a lot of differences behind the scenes So, I cover read

and write operations separately The remainder of this chapter is devoted to read exam-ples Write operations are covered in the next chapter

Retrieving All Records

What we are going to do now is create a PHP page that will access the Product Catalog

database and show a list of all the products Note that there are a couple of PHPisms that you won’t recognize from the PHP chapter I left them out until now because they are

closely related to the use of FileMaker.phpitself I’ll describe them shortly, so just sort of soak everything in for a sec

LISTING 6.1 Example06 01

<?php

define( ‘FM_HOST’, ‘127.0.0.1’ );

define( ‘FM_FILE’, ‘Product Catalog’ );

define( ‘FM_USER’, ‘esmith’ );

define( ‘FM_PASS’, ‘m4rg0t’ );

include (‘FileMaker.php’);

$fm = new FileMaker(FM_FILE, FM_HOST, FM_USER, FM_PASS);

$request = $fm->newFindAllCommand(‘Product’);

$result = $request->execute();

$records = $result->getRecords();

# loop through records compiling row html

$rows = ‘’;

foreach ($records as $record) {

$rows = ‘<tr>’;

$rows = ‘<td>’.$record->getField(‘ID’).’</td>’;

$rows = ‘<td>’.$record->getField(‘Name’).’</td>’;

$rows = ‘<td>’.$record->getField(‘Model Number’).’</td>’;

$rows = ‘<td>’.$record->getField(‘Price’).’</td>’;

$rows = ‘<td>’.$record->getField(‘Created At’).’</td>’;

$rows = ‘<td>’.$record->getField(‘Created By’).’</td>’;

$rows = ‘</tr>’;

}

?>

<html>

<head>

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<body>

<tr>

<th>Model Number</th>

<th>Price</th>

<th>Created At</th>

<th>Created By</th>

</tr>

<?php echo $rows; ?>

</table>

</body>

</html>

Right off the bat, you probably noticed the four “define” lines as something new:

define( ‘FM_HOST’, ‘127.0.0.1’ );

Define is a PHP construct that is similar to a variable in that you are specifying a

name/value substitution, but in this case you are defining a constant In other words, after this line:

define( ‘FM_HOST’, ‘127.0.0.1’ );

…the PHP parser will replace any instance of FM_HOSTwith the value 127.0.0.1for the duration of the script

However, define differs from variables in a couple of ways First, when you use the defined constant, you don’t put a dollar sign in front of it This means that you can’t use any reserved PHP constants as your constants By the way, it’s considered good form to define your constants as uppercase, although it’s not required However, they are case sensitive after you define them, so FM_HOSTis not the same thing as FM_Host

Second, defined constants are purposely very rigid After a constant is defined to have a

value, you cannot redefine it during the course of the script This might seem strange—I’m

basically saying that it’s a variable that can’t vary It’s a constant The nice part about it is that if you try to redefine it anywhere, you get an error This protects you from acciden-tally overwriting a value if you inadvertently reuse a constant name, so for vital informa-tion, defined constants are very handy

LISTING 6.1 Continued

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Still, you are probably asking yourself, “Why would I define FM_HOSTas a constant that

equals127.0.0.1, when I could just use 127.0.0.1?”

Great question The answer is twofold:

If you used 127.0.0.1in hundreds of places within a script (or in many scripts), you would have to carefully replace it in each location it was used if you moved your

host to another IP address Using the define statement allows you to change it in

just one place

Hard-coding sensitive information in a PHP page that is accessible on the Internet is bad from a security standpoint If you look at the third and fourth defined

constants, you will see that I am embedding database login information in the

current page This is considered a security risk, but I don’t want to confuse the topic

at hand I’ll cover this in more detail in Appendix B, “Security Concerns.”

Moving on…

Theincludestatement is supercool It allows you to, well, “include” the contents of

another file into the current file So, whatever’s inside the FileMaker.phppage might as well have been cut and pasted into this page

This is great when you have things like config pages, or global pages that need to get

reused in lots of other pages It lets you write something once and then use it all over

the place

In this case, the engineers at FileMaker, Inc have written a page called FileMaker.phpand

we want to include their work in our page without having to cut and paste all their code

from their file into our file (and, yes, it’s a lot of code) As time goes by and FMI releases

updates to FileMaker.php, we won’t have to worry about our pages—they will automati-cally have the updated code included Pretty sweet, no?

The next line is

This line represents a big juicy can of worms known as object-oriented programming

(OOP) I’d love nothing more than to get into a long discussion about the relative merits

of OOP, but that would be totally beside the point Put another way, you don’t need to understand OOP to use FileMaker.php, any more than you need to understand the inter-nal combustion engine to drive to soccer practice

However, there are two OOP terms that I will be using quite a bit: object and method I will

clarify these terms by example throughout the remainder of this chapter

Here’s that line again:

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This line creates a FileMaker connection object for a particular user (esmith) with pass-word (m4rg0t) to a particular FileMaker file (Product Catalog) on a particular FileMaker Server machine (127.0.0.1)

In this case, that connection object is then stored in the $fmvariable

Here are a few examples of other possible “FileMaker connection” strings:

$fm = new FileMaker(‘Product Catalog’, ‘127.0.0.1’, ‘esmith’, ‘m4rg0t’);

$connection = new FileMaker($ClassFile, ‘localhost’, ‘barbO’, ‘s34f2kAFed32!dk’);

$dbh = new FileMaker(‘TimeTracker.fp7’, ‘jonathanstark.com’, $username, $password);

As you can see, you are free to choose any variable in which to store the connection object Also, you can specify your parameters any way you want, as long as you keep them in the correct order After you have the connection object stored in the $fmvariable,

we can ask it to do stuff for us Let’s look at the next line:

Objects contain methods A method inside of an object is sort of like a script inside of a FileMaker Pro file—you call it, maybe with some parameters Then, it does what you asked, and maybe returns a result to you If a method returns a result, it could be text, a number, or even another object You can then store the result of the method in a variable

newFindAllCommand()is a method of the FileMaker connection object Here, we are telling our$fmconnection to create a new FindAllCommandon the Product layout This is sort of

like going into find mode on the product layout in FileMaker Pro

Remember, I just said that methods can return things, and sometimes that returned thing

is yet another object As it happens, the newFindAllCommand()method returns a Find All object that I am storing here in the $requestvariable

I can now call the execute()method of the Find All object stored in the $request

variable:

As you can probably guess, this is where I am executing the request I created on the pre-vious line The result of the request is yet another object, which is then stored in the

$resultvariable

If you are not familiar with OOP, your head is probably swimming right now Try not to worry about it too much In my experience, the explanation of OOP is more confusing that just looking at a few examples If you are struggling, just keep playing with the examples until you feel like you are starting to feel comfortable Then, read the explana-tion again Rinse, repeat

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When I first started using the newFindAllCommand()method, I was a little peeved

that it was a two-step process: I had to create it on one line, and then execute it on

another I wondered why it didn’t just execute right away and give me all my records

As I became more familiar with FileMaker.php, the reason became clear I might want

to do more than merely find all the records For example, I might want to request that

the records be returned sorted by one or more of the fields in the resultset Placing

the execute command on a separate line allows for this “sort” of thing (pun intended)

You might think that the result of executing the FindAllCommandon the Product layout would contain all of the records from the Product table, and you’d be right! But only

about half right The result object actually contains much more, like the found set count, the total number of records in the table, a list of fields that are on the layout, and so on For now, we are just concerned with the records

To pull just the records out of the result object, you use the getRecords()method:

After this line executes, the $recordsvariable will contain an array of record objects (yep, arrays can contain objects) We can loop through the array of record objects with our

trustyforeachloop to create rows for an HTML table:

$rows = ‘’;

$rows = ‘<tr>’;

$rows = ‘</tr>’;

}

Just like all of the other objects we have seen so far, the record objects have methods

Here, I am using the getField()method of each record object to pull the field values out The parameter of the getField()method is the name of the field as defined in FileMaker for the Product table

The other thing I should explain about this chunk of code is the =concatenation opera-tor This is a commonly used shorthand that tells the PHP parser to append data to a

variable, rather than overwriting the previous contents of the variable

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So, this:

$rows = ‘<tr>’;

is shorthand for this:

$rows = $rows ‘<tr>’;

After the foreachloop is closed, I close the phpblock and output the bulk of the page as literal HTML Nothing special here until you get down to this line:

All I’m doing is using a little bit of PHP to echo out the HTML for the table rows that I compiled in the PHP section previously This will be a common paradigm throughout the rest of the book: First, dynamic data is gathered from the database and converted to HTML, and then the dynamically created HMTL is inserted into key spots of a mostly

static HTML document I refer to this as a template method.

I used an alternative method in the PHP chapter where everything was echoed out by PHP That was fine at the time because the HTML was pretty simple However, as the HTML gets more complicated, it becomes quite a chore to escape all your single and double quotes For this and other reasons, I find that using an HTML template method is much better for real-world applications

Sorting Records

Now I am going to slightly modify the previous example to show you how to allow the user to sort the product records by clicking a column header

LISTING 6.2 Example06 02

<?php

define( ‘FM_HOST’, ‘127.0.0.1’ );

if(isset($_GET[‘sortby’]) and $_GET[‘sortby’] != ‘’) {

$request->addSortRule($_GET[‘sortby’], 1);

}

$rows = ‘’;

$rows = ‘<tr>’;

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$rows = ‘</tr>’;

}

?>

<html>

<head>

</head>

<body>

<tr>

<th><a href=”06_02.php?sortby=Model+Number”>Model Number</a></th>

<th><a href=”06_02.php?sortby=Price”>Price</a></th>

<th><a href=”06_02.php?sortby=Created+At”>Created At</a></th>

<th><a href=”06_02.php?sortby=Created+By”>Created By</a></th>

</tr>

</table>

</body>

</html>

Listing 6.2 is exactly like 6.1 with the following exceptions:

I have converted the table header cells into sort links

I modified the PHP to check for and handle sorting

Let’s look at the PHP first:

}

New PHP alert! This is the first time you have seen the isset()language construct and theandoperator Let’s cover the andoperator first

Inside of an ifexpression, the andoperator is used to separate two conditions that both

must be true for the ifexpression as a whole to be true As you might guess, there’s an or

LISTING 6.2 Continued

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operator that you can use to separate conditions where only one or the other (or both) need to be true for the ifto evaluate to TRUE

Theisset()language construct just checks to make sure that a variable or array element exists It can be empty, but as long as it exists, isset()returnsTRUE

I am using isset()here because I would have gotten a PHP warning if $_GET[‘sortby’]

didn’t exist and I had done this:

if($_GET[‘sortby’] != ‘’) {

So, I am checking to see whether the $_GETsuperglobal array contains any information for‘sortby’ The first time the page loads, there isn’t any data there, so the code inside

of the ifblock is skipped (hence the isset()check) However, after the page has loaded, the user could click one of the links in the column headers:

<th><a href=”06_02.php?sortby=Model+Number”>Model Number</a></th>

<th><a href=”06_02.php?sortby=Price”>Price</a></th>

<th><a href=”06_02.php?sortby=Created+At”>Created At</a></th>

<th><a href=”06_02.php?sortby=Created+By”>Created By</a></th>

Notice that each of the links is pointing to the current page, but with a different field name specified as the sortbyvalue in each

NOTE

You might be wondering, “What’s with the + symbols in the column header hrefs?”

Remember,hrefsare URL strings that need to be read by your browser, and URLs

can’t have spaces So, you need to “URL encode” your hrefsto be browser friendly The + symbol can be used in place of spaces in URL strings You can also use %20, but I find the + symbol easier on the eyes

When a user clicks one of the column header links, the current page is rerequested, but this time $_GEThas a field name specified in sortby Therefore, the code inside the if

block gets executed

Let’s look at it:

Here, I am modifying the newFindAllCommand()that is stored in the $requestvariable by calling the addSortRule()method of the FindAllCommandobject The addSortRule()

method has two required parameters, and a third optional parameter:

Field Name

Precedence

Order

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Just for reference, here’s an example of what it would look like if I wanted to sort all

product records first descending by Price, and second, ascending by Name:

$request->addSortRule(‘Price’, 1, FILEMAKER_SORT_DESCEND);

$request->addSortRule(‘Name’, 2, FILEMAKER_SORT_ASCEND);

$result = $request->execute()

If you omit the third parameter, FileMaker assumes you want the order to be ascending Notice that I am not storing the result of the addSortRule()method in a variable, as I

have done for other methods That’s because the addSortRule()method does not return

a result, so there is nothing to store for later reference

In the example, I’m allowing the user to dynamically specify the field name for the

addSortRule()method by clicking one of the column headers

Finding Records

Let’s further modify this product list example to allow users to supply some search criteria

to filter the results by product name The modifications will be:

Update the PHP to accept search criteria

Include a search form in the HTML

Update the sortbylinks to include the search criteria, If any

Here is the completed example:

<?php

define( ‘FM_HOST’, ‘127.0.0.1’ );

if(isset($_GET[‘search’]) and $_GET[‘search’] != ‘’) {

$search = $_GET[‘search’];

$request = $fm->newFindCommand(‘Product’);

$request->addFindCriterion(‘Name’, $search);

} else {

$search = ‘’;

}

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$rows = ‘’;

$rows = ‘<tr>’;

$rows = ‘</tr>’;

}

?>

<html>

<head>

</head>

<body>

<p>

Product Name Search:

</p>

</form>

<tr>

➥&sortby=ID”>ID</a></th>

➥&sortby=Name”>Name</a></th>

➥&sortby=Model+Number”>Model Number</a></th>

➥&sortby=Price”>Price</a></th>

➥&sortby=Created+At”>Created At</a></th>

➥&sortby=Created+By”>Created By</a></th>

</tr>

</table>

</body>

</html>

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