How do you update a document in KeystoneJS on save click?

问题

I want to update specific fields in a document after changing another field. I've got a product code and a few fields like price and title which I get from an external api.

I want to update the price and title in the document whenever someone changes the product code in the backend. First I tried using a mongoose post save hook on the schema. This resulted in an endless loop, since it kept updating and thus saving the document, after saving the document. Then I implemented a boolean to make sure the post save hook is called only once, which looks something like this:

let postSaveTriggered = false;

//update our product!
Product.schema.post('save', function(doc, next) {
    if (!postSaveTriggered) {
        postSaveTriggered = true;
        api.product.updateInfo(doc, function() { //this updates the document
            next();
        });
    } else {
        postSaveTriggered = false;
        next();
    }
});

But I only want this function to trigger when a user actually changes the product code, not when the product is updated in general. I'm also running a cron job to update the prices of the products and I obviously don't want the post save hook to trigger at all in this scenario. Is there any way to achieve what I want using the KeystoneJS backend?

回答1:

Found a way!

First use a pre save hook to watch for changes in the product code:

let updateProduct = false;

Product.schema.pre('save', function(next) {
    updateProduct = this.isModified('code');
    next();
});

Then simply only update in the post save hook when updateProduct is true:

Product.schema.post('save', function(doc, next) {
    if (updateProduct) {
        updateProduct = false;
        api.product.updateInfo(doc, function() {
            next();
        });
    } else {
        next();
    }
});

Works for me, still seems unnecessary complicated though.

来源：https://stackoverflow.com/questions/48065200/how-do-you-update-a-document-in-keystonejs-on-save-click

标签

node.js

mongoose

keystonejs