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we have a RESTful API that includes an endpoint for search

apiserver/v5/search?q=[search text]

for any query, it passes it off to solr and returns the result like

{code:200,results:[{..},{...}]}

if q parameter is omitted, it returns:

{code:412,message:"parameter q is required"}

if q parameter is EMPTY, eg ?q= then it also returns 412: if q parameter is omitted, it returns:

{code:412,message:"parameter q is empty"}

The design is the the search PAGE with eg example.com/search?q= will show a default view and not make the query if it is empty, but instead just show a search box or default information.

My question is, Is it poor design or very non-standard to have the API return error on empty query? ie, does it make the API very unexpected/uncomfortable, or is it quite reasonable, to enforce that "you won't get results so you should be handling this in front end behavior"

Below is the full relevant code.

NOTE: this is the real code. search function handles all the validation and sanitation and other stuff and is outside the scope of the relevant code and question

<?php
require('search.php');
if(!isset($_GET['q'])
 echo '{code:412,message:"parameter q is required"}';
// should we do this to enforce they should handle front end?
if(empty($_GET['q']))
 echo '{code:412,message:"parameter q is empty"}';
echo search($_GET['q']);

we have a RESTful API that includes an endpoint for search

apiserver/v5/search?q=[search text]

for any query, it passes it off to solr and returns the result like

{code:200,results:[{..},{...}]}

if q parameter is omitted, it returns:

{code:412,message:"parameter q is required"}

if q parameter is EMPTY, eg ?q= then it also returns 412: if q parameter is omitted, it returns:

{code:412,message:"parameter q is empty"}

The design is the the search PAGE with eg example.com/search?q= will show a default view and not make the query if it is empty, but instead just show a search box or default information.

My question is, Is it poor design or very non-standard to have the API return error on empty query? ie, does it make the API very unexpected/uncomfortable, or is it quite reasonable, to enforce that "you won't get results so you should be handling this in front end behavior"

Below is the relevant code.

NOTE: search function handles all the validation and sanitation and other stuff and is outside the scope of the relevant code and question

<?php
require('search.php');
if(!isset($_GET['q'])
 echo '{"code":412,"message":"parameter q is required"}';
// should we do this to enforce they should handle front end?
if(empty($_GET['q']))
 echo '{"code":412,"message":"parameter q is empty"}';
echo search($_GET['q']);