I was learning mongoose, and I am trying to figure out.
Why toObject() was needed to convert the data received into Object, when it was already in object form it seems
Here is the code:
UserSchema.methods.toJSON = function() {
var user = this;
var userObject = user.toObject();
return _.pick(userObject, ['_id', 'email']);
};
I cannot understand why toObject() was used to extract the meaningful properties from the object.
Thanks
toObject is a mongoose document method Document.prototype.toObject() which:
Converts this document into a plain javascript object, ready for storage in MongoDB.
You can more about it here
The reason it is called there is because a plain JS object is required in order to do the lodash _.pick which would create a new object with only _id and email properties.
Related
I am using Google diff-match-patch JAVA plugin to create patch between two JSON strings and storing the patch to database.
diff_match_patch dmp = new diff_match_patch();
LinkedList<Patch> diffs = dmp.patch_make(latestString, originalString);
String patch = dmp.patch_toText(diffs); // Store patch to DB
Now is there any way to use this patch to re-create the originalString by passing the latestString?
I google about this and found this very old comment # Google diff-match-patch Wiki saying,
Unpatching can be done by just looping through the diff, swapping
DIFF_INSERT with DIFF_DELETE, then applying the patch.
But i did not find any useful code that demonstrates this. How could i achieve this with my existing code ? Any pointers or code reference would be appreciated.
Edit:
The problem i am facing is, in the front-end i am showing a revisions module that shows all the transactions of a particular fragment (take for example an employee details), like which user has updated what details etc. Now i am recreating the fragment JSON by reverse applying each patch to get the current transaction data and show it as a table (using http://marianoguerra.github.io/json.human.js/). But some JSON data are not valid JSON and I am getting JSON.parse error.
I was looking to do something similar (in C#) and what is working for me with a relatively simple object is the patch_apply method. This use case seems somewhat missing from the documentation, so I'm answering here. Code is C# but the API is cross language:
static void Main(string[] args)
{
var dmp = new diff_match_patch();
string v1 = "My Json Object;
string v2 = "My Mutated Json Object"
var v2ToV1Patch = dmp.patch_make(v2, v1);
var v2ToV1PatchText = dmp.patch_toText(v2ToV1Patch); // Persist text to db
string v3 = "Latest version of JSON object;
var v3ToV2Patch = dmp.patch_make(v3, v2);
var v3ToV2PatchTxt = dmp.patch_toText(v3ToV2Patch); // Persist text to db
// Time to re-hydrate the objects
var altV3ToV2Patch = dmp.patch_fromText(v3ToV2PatchTxt);
var altV2 = dmp.patch_apply(altV3ToV2Patch, v3)[0].ToString(); // .get(0) in Java I think
var altV2ToV1Patch = dmp.patch_fromText(v2ToV1PatchText);
var altV1 = dmp.patch_apply(altV2ToV1Patch, altV2)[0].ToString();
}
I am attempting to retrofit this as an audit log, where previously the entire JSON object was saved. As the audited objects have become more complex the storage requirements have increased dramatically. I haven't yet applied this to the complex large objects, but it is possible to check if the patch was successful by checking the second object in the array returned by the patch_apply method. This is an array of boolean values, all of which should be true if the patch worked correctly. You could write some code to check this, which would help check if the object can be successfully re-hydrated from the JSON rather than just getting a parsing error. My prototype C# method looks like this:
private static bool ValidatePatch(object[] patchResult, out string patchedString)
{
patchedString = patchResult[0] as string;
var successArray = patchResult[1] as bool[];
foreach (var b in successArray)
{
if (!b)
return false;
}
return true;
}
I am having an issue accessing some objects in cloud code.
I am trying to send a push to array of users everytime a message object is save on parse. Here is the beginning of my code :
// To send push whenever a message is sent
Parse.Cloud.afterSave("Message", function(request) {
// Our "Comment" class has a "text" key with the body of the comment itself
var messageText = request.object.get('text');
var messageUserFirstName = request.object.get('user').get('firstName');
var usersId = [];
var conversation = request.object.get('conversation').get('group1').get('users');
In my Message table, I have a pointer to the class Conversation, which has also a pointer to a class Group, which contains an array of Users pointers. It seems I cannot access this array with the following line:
var conversation = request.object.get('conversation').get('group1').get('users');
Am I doing something wrong?
Thanks.
Your 'user', 'conversation', and 'group1' objects will all need to be fetched before you can access their data.
I apologize if this is a stupid/newb question, but when a Rally query result is returned with a _ref (using the Javascript SDK 1.32), is there a way to directly get the object associated with the _ref?
I see that I can use getRefFromTypeAndObjectId to get the type and the object ID, and then query on that type and object ID to get the object, however I wondered if there was something like getObjectFromRef or some other such way to more directly get back the object associated with the reference.
Excellent question. The getRallyObject method on RallyDataSource should do what you need.
var ref = '/defect/12345.js';
rallyDataSource.getRallyObject(ref, function(result) {
//got it
var name = result.Name;
}, function(response) {
//oh noes... errors
var errors = response.Errors;
});
In SDK 2.0 you use the load method of a data model to read a specific object. Check out this example: http://developer.help.rallydev.com/apps/2.0p5/doc/#!/guide/appsdk_20_data_models
I create a JSonStore with a JSON formatted array of objects.
I have verified it is properly formatted.
I then try to use a dojo forEach loop on it but the JSonStore doesn't seem to have any data in it. I can specify the target in my web page URL and it shows the right data. But using console.log(myJsonStore) shows an object but I don't see the data in Firebug. I also don't see any GET for the service providing the data. It's like specifying the target path in a URL in the browser fires the GET but not when I try to trigger it in the postCreate where my foreach is located.
The answer from Ricardo, i believe is a little incorrect, seeing as the JsonRest.query function returns a dojo.Deferred.
You have a REST call being made asynchroniously through store read api - and once it returns values, it will promise to run whats set as the callback.
Try this for your loop iterator instead
storeObj.query( {} ).then(function ( results ) {
dojo.forEach( results, function( obj ) {
console.log( obj );
});
}
you can do this:
var storeObj = new JsonRest({
target: "/some/resource"
});
storeObj.query({}).forEach(function(obj){console.log(obj);});
that should do the trick
i am creating an object like this:
var myObj:Object = new Object();
myObj["someProperty"] = {
anotherProperty: "someValue",
whateverProperty: "anotherValue"
}
now i want to send it to a web server (rails):
var service:HTTPService = new HTTPService();
service.url = "http://server.com/some/path/entry.json";
service.method = URLRequestMethod.POST;
service.send( myObj );
the problem is that the server receives the json like this:
{"someProperty"=>"[object Object]"}
is this a problem with HTTPService? should i use the good old loader/urlrequest and serialize myself? by the way, serializing and then passing the string doesn't work, webserver receives empty request as GET.
but i kinda want to use the httpservice class though...
You can use a SerializationFilter with your HTTPService to correctly serialize the data you pass as an object to HTTPService.send().
The way in which this works is to create a custom SerializationFilter to perform the specific action required. In your case, you want to convert the outgoing body Object to a JSON format String. To do this you should override the serializeBody method:
package
{
import mx.rpc.http.AbstractOperation;
import mx.rpc.http.SerializationFilter;
import com.adobe.serialization.json.JSON;
public class JSONSerializationFilter extends SerializationFilter
{
override public function serializeBody(operation:AbstractOperation, obj:Object):Object
{
return JSON.encode(obj);
}
}
}
You can assign an instance of this filter to your HTTPService before calling send():
var service:HTTPService = new HTTPService();
service.url = "http://server.com/some/path/entry.json";
service.method = URLRequestMethod.POST;
//add the serialization filter
service.serializationFilter = new JSONSerializationFilter();
service.send( myObj );
Once assigned, this filter will be invoked for all the operations this HTTPService instance performs. You can also add more override methods to your custom filter to handle the incoming response.
I highly recommend using Mike Chamber's JSON serialization library for encoding / decoding (serializing) data in JSON.
Basically, you need to convert your object into a JSON representation. The JSONEncoder class is useful for this.
There's a useful (old but still very relevant for using HTTPService + JSON) tutorial that goes through it, but essentially you should call JSON.encode() on what your "someProperty" value is.
i.e.:
var dataString:String = JSON.encode(dataValue);
dataString = escape(dataString);
myObj["someProperty"] = dataString;