php and files | Still Plugging Away

For our first look at file handling using php, we use the example of logging access to your pages. Topics include:

'file' - named set of data
stored in a directory
work with using specific functions:
- fopen
- flock
- fwrite
- fflush
- fclose

Note: I strongly suggest you view all our videos in full screen mode: click the icon in the lower right corner of the video area (it shows four arrows pointing to the corners of the screen). When you are done, the Esc ("escape") key returns you to regular mode.

Lesson 9: File handling
Part 1: Creating log files

Click here for the video transcript

First, create a Logs directory on your personal computer and on your server. (If you need it, here's a brief video demonstrating this process.)

Now add code to your Feedback.php to log users submitting suggestions:

Open your Feedback.php CGI and ...
- Before the main logic, add variable declares, for example:
  - $now = date('H:m:s');
  - $today = date('Y-m-d');
  - $logname = $today."-Suggestions.txt"; Note the file name
  - $logMsg = "$now: Suggestion passed on to us by $who \n";
  - $logfile = "../Logs/".$logname;
- Before the php end ("?>"):
  add six lines to write to your Feedback log file
  (you fill in the details):
  - fopen
  - flock
  - fwrite
  - fflush
  - flock
  - fclose

Now, add code to your AddTraveler.php, to log users submitting applications to join your trip:

Open your AddTraveler.php CGI and ...
- After the declares of the work variables,
  add variable declares for logging, for example:
  - $logTime = date('H:m:s');
  - $logDay = date('Y-m-d');
  - $logname = $today."-Travelers.txt"; Note the file name
  - $logMsg = "$logTime: New sign up for Wales trip: $fname $lname \n";
  - $logfile = "../Logs/".$logname;
- Before the php end ("?>"),
  add six lines to write to your Travelers log file
  (you fill in the details):
  - fopen
  - flock
  - fwrite
  - fflush
  - flock
  - fclose

Upload your updated Feedback.php and AddTraveler.php files to your cgis directory

Test your updated Feedback.php by entering some suggestions and test your updated AddTraveler.php by entering info for new fictious travelers.

Download your Travelers and Suggestions log files to your PC and open the files to spot errors; fix any problems you may find.

Session 2

How to read files on your server. Topics include:

php I/O functions for reading files
- fopen()
- fgets()
- feof()
- fclose()
Logic flow control
- while
- exit()
- goto
- labels

Lesson 9: File handling in php
Part 2: reading files on your server

Click here for the video transcript.

First, add a new input control in your signUpForm.shtml:

location: after the picture file request, before the "how did you hear about this" control

descriptive text: "What country passport are you traveling on?"

then the input control: type=text, name=passport, size=20, maxlength=40

save the updated file and upload it to your server.

Next add code to your AddTraveler.php to look up the passport value in the Countries file:

The logic for this process is very similar to that in the lecture, and I'm confident you can figure this out yourself. Choose any one of the five general logic structures from the lecture; try all five if you're comfortable with that.

Note: I found it's very important to trim the value returned from fgets() here

After each CGI code update, save and upload the revised code to your cgis directory, and test.

Your tests should try some deliberately mis-spelled names. Note the list does not necessarily reflect any current geo-political situation; in a real world application it would be updated based on changing alliances, sanctions, and / or other political considerations.

Entries in the Countries list are all lower case and in ascending alphabetical sequence.

I thought it might be helpful to the user to provide a little more information if the passport country was not successful. So this option will display the country before and after the submitted country, alphabetically. This way the user can possibly spot their error. So you'll modify cgis/AddTraveler.php.

So the idea is to save the previous and current values from Countries, and if the submitted passport country ($passport) < current value ($work), then display the previous and current entries as part of the routine where the passport test fails.

One possible approach: create a variable, $previous, initialized to 'before_start_of_list'; then in your checking loop, first test for equality of $work and $passport - if equal, go to your passport match routine; but if $passport < $work, go to the routine for handling passport test failure; if you fall through both of these if's, then you have $passport > $work, so save $work into $previous in preparation for the next iteration. In your passport failed routine create a small reply page and, echo something like:

"<p>The nearest countries to yours are $previous and $current</p>";

then give the user the option to use the back button and retry or to close their window and stop their trip application.

In your passport match routine, simply continue the work of the CGI (that is, fall through to your routine creating the user file name and supplying defaults for missing values).

As before, save your updated code, upload it to your server, and test that this works.

Session 3

How to use form data to build a personal web page. Topics include:

How to build a model for a web page
How to access information about an uploaded file
How to move uploaded files to a permanent location
How to read files on your server, updating data with form data
How to create a file on your server and write data into it
New useful functions
- getimagesize()
- file_exists()
- move_uploaded_file()

Lesson 9: File handling in php
Part 3: creating web pages from form data

Click here for the video transcript.

Create a sample result file
Create your ModelTraveler.txt file
Update AddTraveler.php to create a new file for a trip applicant

Create a sample result file

First, copy img_0598.jpg from AdvancedWebFiles/images into your website's /images directory, and rename it to "PatriciaAragon.jpg".

Next, create a page that looks like you want your final applicant pages to look like. Use your tripsite.shtml file as a model: open tripsite.shtml and do a "Save as" using PatriciaAragon.shtml for the name. Now, make the following changes ...

In the <title> element, code: Patricia Aragon
After the <title> element, add a <style> element with one entry:

.picBox {padding-left: 10px; margin-left: 7px; float: right;}
In the <h1> element, replace
"Welcome to the Table and Fable eating and reading club"
with "Travelers on our Journey to Wales"
and for the following line, replace
"tripsite pages" with "<br>Patricia Aragon"
and remove the remaining content of the <h1> element
Replace the entire content inside the <div> element with class=contentColumn with:
- A <div> element with class=picBox containing a <p> element containing an <img> element with width=640, src=travelers/PatriciaAragon.jpg, alt="No Photo Available" title="PatriciaAragon"
- A <p> element with class=bold12 containing underlined text:
  Personal information
- A <p> element with no class containing the line:
  Cell phone <span class=red> 303-555-1548</span><br> followed by a line:
  Email: <a href="mailto:Pat43@gmail.com">Pat43@gmail.com</a>
- A <p> element with no class containing the line:
  Street Address:
- A <blockquote> element with no class containing a <p> element with no class containing the lines:
  37 Lilac Lane<br>
  Ambrosia, Monmarte<br>
  Candelonia
- A <p> element with no class containing the line:
  Birthday: March 7, 2001
- A <p> element with class=bold12 containing underlined text:
  Connections to Wales
- A <p> element with no class containing the text:
  My mum is from Wales, and we visit her side of the family every other year or so. It's a delightful country with an unspeakable language
- A <p> element with class=bold12 containing underlined text:
  What I hope to get out of this trip
- A <p> element with no class containing the text:
  This will be a chance to see parts of the country I've not visited before, and also a terrific opportunity to visit the scenes from the book
- A <p> element with class=bold12 containing underlined text:
  Other sharing
- A <p> element with no class containing the text:
  I'm a huge fan of crwth music, and I'm hoping to hear some in the local pubs during this fun trip.

Upload your PatriciaAragon.shtml file to your website, and check that it looks good to you when you display it. Feel free to tweak it so you're happy with the effect.

Create your model traveler file

Next, use your sample page as the starting point for creating your ModelTraveler.txt file. Include special text where you intend to use form values. (You can use my approach of "**" followed by some text or devise your own methodology.)

Finally, modify your AddTraveler.php to build the new travelers page from form info. Be sure to include tests for duplicate existing files (both the picture and the applicant page). Your resulting code might have these pieces:

Descriptive comments
Get form variables into php variables
Declare working variables, such as
- $addr, $addr_back, $chars, $picOK, $picFileType, and email-, logging-, and passport_country-related variables
Include some prep code:
- Set $ffirst and $flast
- Set $pronoun
Verification / starting code
- Check for valid passport country
- Handle picture upload (if any supplied), including check for already existing filename
- Build filename for user file, and check for already existing file of that name
- Supply defaults for missing values from form
- Construct $addr and $addr_back
Core work:
- Open ModelTraveler.txt for read and $userfile for write
- Change values in ModelTraveler.txt with form values as indicated
- Build reply page
- Schedule display of new page
- Send email to web master
- Log the trip application

Test like crazy!

Session 4

Loose ends and miscellaneous points

Need to create travelers page ("Travelers.shtml")
Need to make an entry on our travelers page
Introduction to the php 'switch' construct
- switch
- break
Thoughts on handling gender

Lesson 9: File handling in php
Part 4: loose ends

Click here for the video transcript.

Create your Travelers.shtml page, keeping it in the same style as your other pages
Add an entry in your Travelers.shtml for Patricia Aragon, pointing to the sample file you created
In your ModelTraveler.txt file, on the line that contains the first and last name of the applicant add the string: **gen
In your AddTraveler.php, work with the gender of the traveler as follows:
- After the code where you set up $ffirst and $flast, add a section "// gender handling" as follows:
  - Set $pronoun to "He" and $gen to "male"
  - If $gender is "F", set $pronoun to "She" and $gen to "female"
  - If $gender is not "M" and not "F", set $pronoun to "They" and $gen to "gender not specified"
- In the part of the code where you are reading ModelTraveler.txt and creating the new personal page:
  - If $roomie = "Y", replace **gen with "($gen)"
  - otherwise replace **gen with ""
Also in your AddTraveler.php, use the 'switch' construct when handling the result from getimagesize()
Test adding some additional travelers; use some of the photos in AdvancedWebFiles/images and make up responses to the various questions
For each new applicant you create, add an entry to your Travelers.shtml page