Oihana PHP Arango

isVariableName.php

Table of Contents

Functions

isVariableName()  : bool
Tells whether a string is a safe AQL **variable** name — the identifier a `LET` binds, not a path to an attribute.

Functions

isVariableName()

Tells whether a string is a safe AQL **variable** name — the identifier a `LET` binds, not a path to an attribute.

isVariableName(mixed $value) : bool

The distinction matters, and isAttributeName() is the wrong guard for this job: it validates a path, so it accepts address.city, which reads perfectly as an attribute and is a syntax error as a variable (LET address.city = …). A variable name is a single identifier: a letter or an underscore, then letters, digits and underscores.

Two failures this cannot see, because they are not about shape:

  • an AQL keyword (LET, RETURN, FILTER, …) has the shape of an identifier and is refused by the server (expecting identifier);
  • a name already bound in the query — doc above all — parses, then fails on execution (variable 'doc' is assigned multiple times).

Both are refused loudly by ArangoDB at the first query, with a message naming the variable, so they surface immediately rather than corrupting a result. Enumerating the keyword list here would only add a copy to keep in sync with the server, and a false sense of completeness.

Parameters
$value : mixed

The candidate variable name.

Tags
example 
use function oihana\arango\db\helpers\isVariableName;

isVariableName( 'authorRef'    ) ; // true
isVariableName( '_ref'         ) ; // true
isVariableName( 'address.city' ) ; // false — a path, not an identifier
isVariableName( '1ref'         ) ; // false — a digit cannot open an identifier
isVariableName( 'my-ref'       ) ; // false
since
1.7.0
author

Marc Alcaraz

Return values
bool —

Whether it is a well-formed AQL variable name.

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