Searching system assessment

Scenario

A system generates events that are stored in a file in the following format: event type, entity name, entity id,
[fields updated], timestamp

Example:

INSERTED, Placement, 12, null, 2018-04-10 12:34:56.789
INSERTED, Placement, 13, null, 2018-04-10 12:43:10.123
UPDATED, Company, 123, [status, companyUrl], 2018-04-10 12:44:00.123
UPDATED, Placement, 13, [status, hoursPerDay, overtimeRate], 2018-04-10 14:52:43.699

You should assume that:

Event type – can be one of INSERTED, UPDATED, DELETED

Timestamp will always be in the format yyyy-MM-dd HH:mm:ss.ms

Fields updated are the names of fields rather actual values

Events will not necessarily be in a predictable order

Requirement

Develop a system that takes an event file (as outlined above) as an input and can support the following functions:

1. Display all events of a specific event type

2. Get all events where a specific field has been updated. For example all events where the ‘status’ field changed

3. Get all events between two timestamps

4. Allow combinations of (1), (2) and (3). For example, all UPDATED events where status
   changed between 2018-04-10 12:00:00.000 and 2018-04-10 12:00:11.500

MY APPROACH

HOW TO RUN THE SYSTEM

Go to a dedicated subdomain at http://assessment.rosiepiontek.com/index.php
and check the project on a live server.

WARNING

The layout of the site most probably breaks on devices with screens
smaller than 15" and using other browser than Chrome.
Responsiveness will be improved later.

If you wish to run it locally:

You will need Apache 2.4.27 and PHP 7.1

Code was tested with PHP 7.2 in live environment and there were issues.

Project is located in 'localhost/assessment'.

In the root directory, create an empty file called 'event-file.txt' and generate random entries.

In my httpd.conf I created a virtual host:

<VirtualHost 127.0.0.1:8082>
<Directory "{$path}/www/assessment">
    Options FollowSymLinks Indexes
    AllowOverride All
    Order deny,allow
    allow from All
</Directory>
ServerName assessment
ServerAlias assessment 127.0.0.1
ScriptAlias /cgi-bin/ "{$path}/www/assessment/cgi-bin/"
DocumentRoot "{$path}/www/assessment"
ErrorLog "{$path}/apache/logs/error_log"
CustomLog "{$path}/apache/logs/access.log" combined
</VirtualHost>

'www' is localhost.

Don't forget to make Apache listen to the new port:

Listen 8082

A separate css reset file is used, taken from https://meyerweb.com/eric/tools/css/reset/reset.css

TESTING THE SYSTEM

Click 'Generate event file' button to randomly create a file on your server with event entries.
All the parts of each event mentioned in 'Requirement' above are randomly generated.

Important note regarding the live version:

At the moment there can by only one event file, so anyone can create a random event file at any time on any device, which will overwrite previously generated event file for everyone.

FUTURE IMPROVEMENTS

[x] Responsiveness of the layout (99% done).

[x] Use Ajax for showing search results, and when generating random entries in 'event-file.txt'.

[x] Make 'INSERT' event not contain any [fields updated] but only 'null'.

[x] Make 'UPDATE' event not contain any 'null' but only [fields updated].

[x] Show summary of the result above the red box.

[ ] Make the CSS not break on same screen sizes.

[ ] Add option for sending search results by email.

[ ] Let users generate their own random file, to avoid situation when a user overwrites other user's event-file.

[ ] Show results in chronological order.

[ ] Add icons to buttons.