CODEWITHSUNDEEP
parse-platformparse-cloud-code
Can Poyrazoğlu
Can Poyrazoğlu

Reputation: 34780

How to prevent user editing a specific column while still having write access to the object on Parse?

I have some specific columns on my _User class that I want to edit only with master key at the server side. My User does have write access to itself. Is there a way to prevent my user from editing specific columns, for example, let's say I have a user object and I want user to prevent editing its own points:

before save trigger:
 if(points field have been changed by the user){
  response.error();
 )

It doesn't have to be in before save trigger, but I highly doubt there is any other point to check such "dirty" column, if any. Is there a way to achieve what I need (other than obvious solutions such as creating a new class, setting it's ACL to none, holding a user pointer and a score column and editing that only with master key)?

Upvotes: 2

Views: 854

Answers (1)

mbm29414
mbm29414

Reputation: 11598

Here is the Parse JavaScript Documentation related to "dirty" objects and properties.

{Boolean} dirty(attr)

Returns true if this object has been modified since its last save/refresh. If an attribute is specified, it returns true only if that particular attribute has been modified since the last save/refresh.

Parameters: {String} attr

An attribute name (optional).

Returns: {Boolean}

If you couple that bit (calling dirty("score") with a beforeSave() Cloud Code function), you should get what you want.

Modifying Objects On Save

In some cases, you don't want to throw out invalid data. You just want to tweak it a bit before saving it. beforeSave can handle this case, too. You just call response.success on the altered object.

In our movie review example, we might want to ensure that comments aren't too long. A single long comment might be tricky to display. We can use beforeSave to truncate the comment field to 140 characters:

Parse.Cloud.beforeSave("Review", function(request, response) {
    var comment = request.object.get("comment");
    if (comment.length > 140) {
        // Truncate and add a ...
       request.object.set("comment", comment.substring(0, 137) + "...");
    }
    response.success();
});

Upvotes: 4

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