CODEWITHSUNDEEP
grails
AbuMariam
AbuMariam

Reputation: 3698

How to pass request parameter values for Grails params.list to read them in as array instead of string?

I have the following code in my Grails controller...

def teams = params.list('team')

And in the post being submitted I see in Chrome dev tools network tab...

team:Yankees mets

Two values separated by a space. On the server side this is read as a string, how can I pass the data in so it is read as an array (with "Yankees" being the first element and "mets" the second)?

I tried separating the values by comma instead but that didn't work either.

Upvotes: 0

Views: 2016

Answers (1)

Joshua Moore
Joshua Moore

Reputation: 24776

It's important to understand what params.list() expects you to submit to it and how that differs from other ways of sending in array like data.

params.list() expects that you submit the same parameter multiple times either via GET or POST an example of such a form would be:

...
<input type="text" name="team" value="One" />
<input type="text" name="team" value="Two" />
...

Which would result in the following being posted as form data:

team=One
team=Two

The above example as a querystring (used in a GET) would look like:

?team=One&team=Two

As you can see from the above params.list() expects you to submit your data in a very specific way so it understands how to parse it into a collection (e.g. list).

If, however, you wish to use a single field and separate your data using some token (such as a comma) you could parse the value of the single parameter into a list using either tokenize() or split(). For example:

List teams = params?.team?.tokenize(',')

You'll have to be careful about handling empty/null values. Also the above example expects that param.team is going to be a String (important to note if your are sending a comma separated list of numeric values and only one value is present).

Upvotes: 2

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