Mercury: Venus: Earth: Mars: Jupiter: Saturn: Uranus: Neptune: Pluto:
Explanation of Web Page Functionality
The aforementioned request string is sent off to a PHP-based Web Service. If this Web Service receives a correctly-formatted request string, it responds with an HTTP header of ‘200 OK’ and an unstyled HTML table containing statistics relating to the selected planet. The HTML table has an ‘id’ attribute named ‘stylable’ so that the client can format the table in an aesthetically-pleasing manner. In this example, a border is added to all the table cells, the font colour is set to black, and the background colour of each table cell is set to ‘khaki’.
If this Web Service receives an incorrectly-formatted request string, it responds with an HTTP header of ‘400 Bad Request’ and a paragraph of text that explains the expected request string format. You can test this response by clicking the ‘Send XMLHttpRequest’ button without selecting a planet; the explanatory paragraph will be displayed above.
The Web Service will only respond with either a ‘200 OK’ or ‘400 Bad Request’ HTTP header. For all other communication issues – for example, a loss of internet connection – an error message will be displayed in red font, informing the user that an ‘unforeseen communication issue’ has occurred.