CODEWITHSUNDEEP
formscoldfusion
Boodyguard
Boodyguard

Reputation: 51

Test if a dynamic variable is defined

I have some input variables with a dynamic name into my form (UUID). To avoid error I test if the variables are defined, but strangely the function IsDefined return me an error (when the field is not sent like a radio or check-box).

The HTML result in the form:

 Yes <input type="radio"id="content_BB66F151-CB09-1C8C-CCF53DE1A92652FC"
name="content_BB66F151-CB09-1C8C-CCF53DE1A92652FC" value="1">  
No <input type="radio" id="content_BB66F151-CB09-1C8C-CCF53DE1A92652FC"
name="content_BB66F151-CB09-1C8C-CCF53DE1A92652FC" value="0">

My CFM: 

Yes <input type="radio" id="content_#qMD.MD_FIELD_ID#"
                        name="content_#qMD.MD_FIELD_ID#" value="1"> No <input type="radio" id="content_#qMD.MD_FIELD_ID#" name="content_#qMD.MD_FIELD_ID#" value="0">

My CFM test: I have a list of all MD_FIELD_ID and loop over them

<cfloop list="#attributes.lMetadataField#" index="MD_FIELD_ID" delimiters="," >
<cfif IsDefined("attributes.content_" & MD_FIELD_ID)>
</cfif>

Coldfusion return me this when the field is not in the submitted form:

Parameter 1 of function IsDefined, which is now attributes.content_BB66F151-CB09-1C8C-CCF53DE1A92652FC, must be a syntactically valid variable name.

I have tried different syntaxes: 

 IsDefined("attributes.content_#MD_FIELD_ID#") or
attributes["content_#MD_FIELD_ID#"]

but always the same error. If the field is in the submitted form, it works fine.

What is wrong in my code ?

Upvotes: 3

Views: 1007

Answers (1)

Alex
Alex

Reputation: 7833

You may not use hyphens (and various other characters like : or #) for struct key names (i.e. variables) when providing as argument to isDefined. Instead you can do:

<cfif structKeyExists(attributes, "content_" & MD_FIELD_ID)>

structKeyExists doesn't evaluate the expression and thus is not subject to the variable name parsing. However, due to that fact you cannot chain structKeyExists as conveniently.

Example:

isDefined("someStruct.parentKey.childKey")

translates to

structKeyExists(VARIABLES, "someStruct")
and structKeyExists(someStruct, "parentKey")
and structKeyExists(someStruct["parentKey"], "childKey")

Notice how you need to check existence for every single key in the chain. But it allows to use any character as key name.

Upvotes: 6

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