The Mongoose docs suggest overriding the default value of [] for an array field like this:
new Schema({
toys: {
type: [ToySchema],
default: undefined
}
});
I'd like to have an array of strings, with an enum and with a default value if none is supplied.
Thus, every document has type 'foo' if none is specified, but documents may be 'foo' and 'bar'.
Is that possible?
Although the docs don't mention it, a default value can be given, in the way you'd expect.
You can have an enum array with a default value like this:
new Schema({
toys: {
type:[{ type: String, enum: ['foo', 'bar', 'baz'] }],
default: ['foo']
}
});
Related
I have the following schema:
const mySchema = new mongoose.Schema({
x: String,
y: String
})
when a user from the front-end requests in his body:
req.body = {
'x' : '',
'y': ''
}
this results in creating a field in MongoDB, but with an empty string.
I need a way to prevent this behavior by setting the empty strings to be undefined somehow.
Is there such an option in Mongoose? or do I have to predict my own middlewares for that?
You could use the set method for Mongoose Schemas:
const mySchema = new mongoose.Schema(
{
myAttribute: {
type: String,
set: (attribute: string) => attribute === '' ? undefined : attribute,
},
},
{ strict: 'throw' },
);
This will unset the field if the string equals ''.
Use this to trim the strings:
set: (a: string) => a?.trim() === '' ? undefined : a
You don't need mongoose, or a middleware to handle this. You can just write a quick few lines to check for empty values and exclude them from the MongoDB write operation.
Ex:
const newEntry = Object.entries(req.body).reduce((obj, [key, value]) => {
if (value) obj[key] = value
return obj
}, {})
In this example, I convert the req.body into an array using Object.entries and iterate over it with the Array.reduce method, wherein I add key:value pairs to a new object if there is a value to add. Since an empty string value is falsey I can do a simple if check on the value. I then assign the return of the reduce method to the variable newEntry. Then I would then take the new entry and create the MongoDB document with it.
This could be extracted into a helper method and reused in any of your routes that need to check remove empty values from an object.
Docs on Array.reduce
Docs on Object.entries
I have a Schema definition with a nested object that looks like this:
mongoose.Schema({
name: String,
messages: [{
type: String,
message: String
}]
});
Mongoose doesn't interpret this as I would like because there is a key named type, which conflicts with Mongoose's syntax for defining defaults, etc. Is there a way to define a key named "type"?
Oh, I remember this annoying problem, it took me ages to find out that the problem is that type is read by mongoose schema.
Just specify a type:String inside the type label
mongoose.Schema({
name: String,
messages: [{
type: {type: String},
message: String
}]
});
How to describe object in Mongoose schema to store any property including defined property that should be indexed?
I have Mongoose schema with structure like this:
{
a: { type: Object, require: true }
}
I don't know all fields in object a but I know it contain string b, and I should create index at this field.
I can do something like this:
{
a: {
b: { type: String, require: true, index: true }
}
}
But in this case other properties of object a will be lost.
You can define index on schema level:
yourSchema.index({ "a.b": 1, type: 1 });
I am trying to update my collection which has an array field(initially blank) and for this I am trying this code
Industry.update({_id:industryId},
{$push:{categories: id:categoryId,
label:newCategory,
value:newCategory }}}});
No error is shown, but in my collection just empty documents({}) are created.
Note: I have both categoryId and newCategory, so no issues with that.
Thanks in advance.
This is the schema:
Industry = new Meteor.Collection("industry");
Industry.attachSchema(new SimpleSchema({
label:{
type:String
},
value:{
type:String
},
categories:{
type: [Object]
}
}));
I am not sure but maybe the error is occuring because you are not validating 'categories' in your schema. Try adding a 'blackbox:true' to your 'categories' so that it accepts any types of objects.
Industry.attachSchema(new SimpleSchema({
label: {
type: String
},
value: {
type: String
},
categories: {
type: [Object],
blackbox:true // allows all objects
}
}));
Once you've done that try adding values to it like this
var newObject = {
id: categoryId,
label: newCategory,
value: newCategory
}
Industry.update({
_id: industryId
}, {
$push: {
categories: newObject //newObject can be anything
}
});
This would allow you to add any kind of object into the categories field.
But you mentioned in a comment that categories is also another collection.
If you already have a SimpleSchema for categories then you could validate the categories field to only accept objects that match with the SimpleSchema for categories like this
Industry.attachSchema(new SimpleSchema({
label: {
type: String
},
value: {
type: String
},
categories: {
type: [categoriesSchema] // replace categoriesSchema by name of SimpleSchema for categories
}
}));
In this case only objects that match categoriesSchema will be allowed into categories field. Any other type would be filtered out. Also you wouldnt get any error on console for trying to insert other types.(which is what i think is happening when you try to insert now as no validation is specified)
EDIT : EXPLANATION OF ANSWER
In a SimpleSchema when you define an array of objects you have to validate it,ie, you have to tell it what objects it can accept and what it can't.
For example when you define it like
...
categories: {
type: [categoriesSchema] // Correct
}
it means that objects that are similar in structure to those in another SimpleSchema named categoriesSchema only can be inserted into it. According to your example any object you try to insert should be of this format
{
id: categoryId,
label: newCategory,
value: newCategory
}
Any object that isn't of this format will be rejected while insert. Thats why all objects you tried to insert where rejected when you tried initially with your schema structured like this
...
categories: {
type: [Object] // Not correct as there is no SimpleSchema named 'Object' to match with
}
Blackbox:true
Now, lets say you don't what your object to be filtered and want all objects to be inserted without validation.
Thats where setting "blackbox:true" comes in. If you define a field like this
...
categories: {
type: [Object], // Correct
blackbox:true
}
it means that categories can be any object and need not be validated with respect to some other SimpleSchema. So whatever you try to insert gets accepted.
If you run this query in mongo shell, it will produce a log like matched:1, updated:0. Please check what you will get . if matched is 0, it means that your input query is not having any matching documents.
Does Mongoose support, or is there an available package that supports multiple "options" for the embedded schemas in an array?
For example, the things property can contain only one of two schemas:
new Schema({
things: [{
requiredProp: String,
otherProp: Number
}, {
otherOption: Number
}]
});
In other words, I do not want to just allow anything (AKA Schema.Types.Mixed) to be stored in this property, but only these two possible definitions.
Or, do schema design recommendations exist to avoid this problem?
You should only define one dict in the array type of the schema, and then set if they are required or not with the mongoose schema types logic. Use pre save if you want to do more logic to assure that either one of the fields have been set, like this:
var MySchema = new Schema({
things: [{
requiredProp: {type: String, required: true},
otherProp: Number,
otherOption: Number,
}]
});
MySchema.pre('save', function(next) {
if (!this.otherProp && !this.otherOption) {
next(new Error('Both otherProp and otherOption can\'t be null'))
} else {
next()
}
})
Opon saving the object it will return an error if neither otherProp nor otherOption has been set.