I want to access the data in document in the function were I handle the Item, How can I put the variable document.date in the itemstring?
function pagelist(items, res) {
var db = db_login;
result = "<html><body><ul>";
items.forEach(function(item) {
console.log(item)
db.collection('insights').findById(item._id , function(error, document) {
console.log(document)
if (error || !document) {
res.render('error', {});
} else {
**console.log(document.date) //this value is displayed**
}
})
**console.log(document.date)//this value is undefind**
itemstring = "<li>" + item._id + "<ul><li>" + item.textScore +
"</li><li>" + item.created + "</li><li>" + item.document +
"</li></ul></li>";
result = result + itemstring;
});
result = result + "</ul></body></html>";
return result;
}
The current answers all miss a key point, that your "child" function is a callback from an asyn function. It does not execute before the rest of your "parent" function does.
function pagelist(items, res) {
// ... (1)
items.forEach(function(item) {
db.collection('insights').findById(item._id, function(error, document) {
// this will not execute (4)
});
// before this (2)
});
// or this (3)
// Actual order will be in that of (numbers)
return result;
}
Your only option is you make your parent function behave the same way that your db function does. I.e. make it asyn too.
function pagelist(items, done) { // <= "done"
items.forEach(function(item) {
db.collection('insights').findById(item._id, function(error, document) {
// Now you can call done with document that is available here
done(document); // or done(document.date); w/e
});
// return result; // Returns are useless* in asyncs
}
Wherever you're calling pagelist() from pass it a callback function "done" and do stuff in there
app.use(function(req, res){
pagelist(items, function(document){ // <= this will be the "done" function
var itemstring = document.date;
// do whatever you want with the document here.
res.render(~);
console.log(document.date);
});
});
Try this:
Assign local variable document to global variable doc and access it in outside of the function;
function pagelist(items, res) {
var db = db_login;
var doc;
result = "<html><body><ul>";
items.forEach(function(item) {
console.log(item)
db.collection('insights').findById(item._id , function(error, document) {
console.log(document)
doc=document; // assignment of the local variable to global variable
if (error || !document) {
res.render('error', {});
} else {
console.log(document.date)
}})
console.log(doc.date) // here is use of global variable
itemstring = "<li>" + item._id + "<ul><li>" + item.textScore +
"</li><li>" + item.created + "</li><li>" + item.document +
"</li></ul></li>";
result = result + itemstring;
});
result = result + "</ul></body></html>";
return result;
}
Enjoy :)
Related
i have class [ClassName] and method [- setSomething].
How can i call with JS API withount Interceptor this method?
Function:
function modify_implementation(class_name, method_name, functions) {
try {
var methodObj = ObjC.classes[class_name][method_name]
var old_implementation = methodObj.implementation;
methodObj.implementation = ObjC.implement(methodObj, function () {
var args = [].slice.call(arguments); // modifying Arguments object into array
if(typeof functions['arguments'] === 'function') {
functions['arguments'](args);
}
var result = old_implementation.apply(null, args);
if(typeof functions['result'] === 'function') {
result = functions['result'](result);
}
return result;
});
} catch (err) {
console.log('[!] Error while hooking ' + class_name + ' [' + method_name + ']', err);
}
}
I have a loop that is making up to five calls to an API endpoint to validate ids. My increment variable turns from 0 to 1 on the first iteration before finishing the loop.
I pinpointed that it happens whether the request is good or bad after console logging the variable right before the request and then inside each callback. As soon as the variable is called in the .then callback or the .catch callback, the index is incremented and I have no idea why. I have tested different variable names and still get the same result. Anyone have an idea on this?
I also used the .fetch() method with React and the same thing is happening in the .then function so I don't think this is specific to axios.
Here is my function:
isValidAIN(ains) {
var control = this;
var length = ains.length;
if (ains.length > 0) {
for (var i = 0; i < length; i++) {
if (ains[i].length !== 10) {
if (ains[i].length === 0) {
this.state.errors["ain[" + i + "]"] = "";
this.state.validAINS[i] = true;
} else {
this.state.errors["ain[" + i + "]"] = "This AIN Number Must Contain 10 Digits";
this.state.validAINS[i] = false;
}
this.setState(this.state);
} else {
// v this logs 0
console.log("i: ", i);
axios
.get("/myendpoint/?ain=" + ains[i])
.then((res) => {
// v this logs 1
console.log("in then: ", i);
console.log("res: ", res);
control.state.errors["ain[" + i + "]"] = "";
control.state.validAINS[i] = true;
control.setState(control.state);
})
.catch((err) => {
// v this logs 1
console.log("i in catch", i);
if (err.response.status == 404) {
control.state.errors["ain[" + i + "]"] = "AIN Is Invalid";
console.log(control.state.errors["ain[" + i + "]"]);
control.state.validAINS[i] = false;
control.setState(control.state);
return false;
}
});
// fetch("/myendpoint/?ain=" + ains[i])
// .then(res => res.json())
// .then(
// (result) => {
// console.log("success: ", result);
// if(result == null) {
// control.state.errors["ain[" + i + "]"] = "AIN Is Invalid";
// control.state.validAINS[i] = false;
// control.setState(control.state);
// return false;
// }
// else {
// control.state.errors["ain[" + i + "]"] = "";
// control.state.validAINS[i] = true;
// control.setState(control.state);
// }
// },
// (error) => {
// console.log("error: ", error);
// }
// )
// .catch(
// (err) => {
// console.log("Error from catch: ", err);
// }
// )
}
}
} else {
return false;
}
}
The axios request is asynchronous, and the scope of variables declared with var is the enclosing function. When the axios request is complete, this variable will be the max of the loop, since the loop is synchronous and complete.
Change the var to let for i to use block scoping instead.
for(let i = 0; i < length; i++) { ... }
Because axios calls are asynchronous.
You're performing a for loop that just loops through ains.length, this happens in a few milliseconds. You define i as a var that is incremented after every loop within the for loop.
So if you're in the then / catch, the variable i is already at its maximum (so 1 in your case).
i is a variable and not a constant. When using i you're referencing to that pointer in memory. If you want i to be unique in every loop you should define it as let instead of var. This will create a unique value of i for each invocation of the loop.
I have a http post request which returns ID. I then try to pass that ID into another function. However, inside the next function I have a timeout that will loop the function to check the status. The ID returns undefined each time inside the timeout function.
First Function
Here I have 'res' which is a result from another function. I grab the status ID from the returned json and send it to 'getAlbum'.
anotherFunction(res) {
this.getAlbum(res);
}
GetAlbum
If I do a console log immediately inside this function, it correct emits the correct ID. However, if I do it inside the 'checkAblumStatus' function, the id part is undefined.
getAlbum(id){
var statusID = id.status_id;
console.log('id = ' + statusID) // returns id
var statusIDRequest = 'url' + statusID;
var checkAblumStatus = function (statusIDRequest) {
console.log('statusIDRequest = ' + statusIDRequest) // returns undefined for the ID part
this.http.get(statusIDRequest).subscribe(res => {
if (res.status == "completed") {
// completed
} else if (res.status == "failed") {
// failed
} else {
setTimeout(checkAblumStatus, 1000);
}
});
};
setTimeout(checkAblumStatus, 1000);
}
Any help here would be very grateful :)
This happens because of the scope of your variables.
var checkAblumStatus = function (statusIDRequest) {
console.log('statusIDRequest = ' + statusIDRequest) // returns undefined for the ID part
this.http.get(statusIDRequest).subscribe(res => {
if (res.status == "completed") {
// completed
} else if (res.status == "failed") {
// failed
} else {
setTimeout(checkAblumStatus, 1000);
}
});
};
In the context of your function, this references the function itself, not your object.
You need to use a closure or a fat arrow like this.
var checkAblumStatus = (statusIDRequest) => {
You also need to provide a avariable to your calls.
setTimeout(checkAblumStatus(variable), 1000);
You get confused with variable and param name.
var statusIDRequest = 'url' + statusID;
^ ^ // this variable
var checkAblumStatus = function (statusIDRequest) {
^ ^ // .. is not the same not this param
Change the name of the variable like this, so you don't get rid of the name:
getAlbum(id){
var statusID = id.status_id;
console.log('id = ' + statusID) // returns id
var statusID = 'url' + statusID;
var checkAblumStatus = function (statusIDRequest) {
console.log('statusIDRequest = ' + statusIDRequest) // returns the ID part
this.http.get(statusIDRequest).subscribe(res => {
if (res.status == "completed") {
// completed
} else if (res.status == "failed") {
// failed
} else {
setTimeout( () => checkAblumStatus (statusIDRequest), 1000);
}
});
};
setTimeout(() => checkAblumStatus(statusID), 1000);
}
you can pass the id for the function as follow
function getAlbum(id){
var statusID = id.status_id;
console.log('id = ' + statusID) // returns id
var statusIDRequest = 'url' + statusID;
var checkAblumStatus = ((statusIDRequest) => {
console.log('statusIDRequest = ' + statusIDRequest) // returns undefined for the ID part
this.http.get(statusIDRequest).subscribe(res => {
if (res.status == "completed") {
// completed
} else if (res.status == "failed") {
// failed
} else {
setTimeout(checkAblumStatus, 1000);
}
});
})(statusIDRequest);
setTimeout(checkAblumStatus, 1000);
}
I have the following json which represents pages on a site which have sub pages via an items array, which currently comprises 2 top level items - about and services:
var data = '[{"id":107,"name":"About Us","route":"page","slug":"about","parent":0,"module":1,"items":[{"id":118,"name":"About Sub Page","route":"page","slug":"about-sub-page","parent":107,"items":[]}]},{"id":129,"name":"Services","route":"page","slug":"services","parent":0,"module":1,"items":[{"id":174,"name":"Services sub page","route":"page","slug":"services-sub-page","parent":129,"items":[]}]}]';
I am trying to write a function which iterates recursively over the array of objects (data = JSON.parse(data)) and identify the index of the top level items. For instance, in my function if I use the 'about' slug, it will return 0, as will 'about-sub-page'. Similarly, 'services-sub-page' would return 1.
I have this at the moment:
data = JSON.parse(data);
function check(slug,data) {
var result;
$.each(data, function(index){
if (this.slug === slug) {
result = index;
return false;
}
else {
check(slug,this.items);
}
});
return result;
}
This works fine if I pass a top level slug eg
var index = check('about',data);
console.log(index); // returns 0
var index = check('services',data);
console.log(index); // returns 1
However, if I try with a sub page I get undefined
var index = check('services-sub-page',data);
console.log(index); // returns undefined
I believe I need to return false to break out of the each loop, but not sure why it's not working when I try and use the function recursively.
You could use Array#some(), because this stops iterating if a condition is met.
var data = '[{"id":107,"name":"About Us","route":"page","slug":"about","parent":0,"module":1,"items":[{"id":118,"name":"About Sub Page","route":"page","slug":"about-sub-page","parent":107,"items":[]}]},{"id":129,"name":"Services","route":"page","slug":"services","parent":0,"module":1,"items":[{"id":174,"name":"Services sub page","route":"page","slug":"services-sub-page","parent":129,"items":[]}]}]';
function check(slug, data) {
function iter(a, i) {
if (a.slug === slug || Array.isArray(a.items) && a.items.some(iter)) {
index = i;
return true;
}
}
var index,
array = JSON.parse(data);
array.some(iter)
return index;
}
document.write(check('about', data) + '<br>');
document.write(check('services', data) + '<br>');
document.write(check('services-sub-page', data) + '<br>');
data = JSON.parse(data);
function check(slug,data) {
var result;
$.each(data, function(index){
if (this.slug === slug) {
result = index;
return false;
}
else {
result = check(slug,this.items); // assign to result variable
}
});
return result;
}
So basically I have some promise, forEach, just a lot of issues with this single problem I need to solve. So the variables I work with has below structure:
persons = [object, object, object]
where each object has { user:number , username: string, latitude:number, longitude:number}
from there I try to figure out if my user/username is inside of one of these objects, if not found id like it to be created, if found found id like it to update their location. Sounds simple, I think the problem has blown out of proportion but nothing works. The code I have now does not work, its either I can never figure out when the user is not there, or I can not figure out how to get to stop creating me every time it find a user who is not me.
var getswamp = function(item, index) {
return new Promise(function(resolve, reject){
var result = false;
if (item.user === user && item.username === username) {
if ((item.latitude !== latitudenew) || (item.longitude !== longitudenew)) {
var id = item.id;
swampdragon.update('locationcurrent', {
user: user,
latitude: latitudenew,
longititude: longitudenew,
username: username,
id: id
}, function (context, data) {
console.log("data updated", data);
result = true;
resolve(result);
}, function (context, data) {
console.log("You may not be updated");
});
} else {
console.log("No location change");
result = true;
}
}else{
if ( item.index === person.index){
console.log(person);
resolve(result)
}
}
});
};
person.forEach(function (item, index) {
var swamping = getswamp(item, index);
swamping.then(function (result) {
console.log(result);
if (result === true) {
console.log("We have you");
} else if (result === false && (index === person.length - 1)) {
console.log('Index: ' + index + ' Length of list is ' + person.length);
swampdragon.create('locationcurrent', {
user: user,
latitude: latitudenew,
longititude: longitudenew,
username: username
}, function (context, data) {
console.log("data created", data);
}, function (context, data) {
console.log("You may not be created")
});
}
})
});
Any help/ideas would just be great.
The Promise is used when some asynchronous event happened.
Since I can not create such event, I made a static code as below:
var persons = new Array();
persons.indexOf = function(person) {
var index = -1;
this.forEach(function(obj, i) {
if (person.username == obj.username) {
index = i;
}
});
return index;
}
persons.addOrUpdate = function(person) {
var index = this.indexOf(person);
if (index == -1) {
person.user = this.length + 1;
this.push(person);
}
else { // update case
var obj = this[index];
obj.latitude = person.latitude;
obj.longitude = person.longitude;
}
}
persons.print = function() {
var str = "";
this.forEach(function(obj) {
str += obj.user + ". " + obj.username + " at location (" +
obj.latitude + ":" + obj.longitude + ")\n";
});
return str;
}
persons.addOrUpdate({username:'Adam', latitude:-0.0045, longitude:14.2015});
persons.addOrUpdate({username:'Eve', latitude:-0.0045, longitude:14.2015});
persons.addOrUpdate({username:'Abel', latitude:-0.0045, longitude:14.2015});
// Updating Able location
var person = {username:'Abel', latitude:10.1145, longitude:14.1234};
persons.addOrUpdate(person);
alert(persons.print());