Search items in external JSON - json

Question

I have the URL of a JSON file and I want to get all the items with the same value.
Example:
http://sampleurl.com has this JSON
`{
"posts":[
{
"authors":[
{
{"name":"John",
"age": 30
},
{"name":"John",
"age": 35
}
}
]
}
]
}`
What I want to do is to list all those authors with the same name together with their age.
I have tried this with no success:
`var allposts = "http://sampleurl.com";
$.each(allposts.posts.authors, function(i, v) {
if (v.name == "John") {
alert("Ok");
return;
}
});`
Thanks

Answer 1

You need to get the data via an Ajax call - $.getJSON:
const authors = {};
$.getJSON( "http://sampleurl.com", data =>
data.posts.authors.forEach(author => {
authors[author.name] = authors[author.name] || []
authors[author.name].push(author)
});
);
At the end you have an object keyed on unique author names, with each key containing as its value an array of the authors with that name. You can do further processing to transform that to the data structure you need.
This example doesn't deal with data coming back that isn't in the shape you expect. For example, if some author records are missing a name, you will end up with a key undefined. And if there is no authors key or no posts key in the returned object you will get an exception.
So you have to decide how your program should behave in those cases. Should it explode? Or return an empty object? If you want it to continue with an empty object:
const authors = {};
$.getJSON( "http://sampleurl.com", data =>
if (data.posts && data.posts.authors) {
authors.forEach(author => {
const name = author.name || 'unknown';
authors[author.name] = authors[author.name] || []
authors[author.name].push(author)
});
} else {
console.log('Warning! Data from API did not contain posts.authors!')
}
);
Note that neither of these examples deal with the AJAX call itself failing. For that you need to chain a .fail() handler:
const authors = {};
const url = "http://sampleurl.com"
$.getJSON( url, data =>
if (data.posts && data.posts.authors) {
authors.forEach(author => {
const name = author.name || 'unknown';
authors[author.name] = authors[author.name] || []
authors[author.name].push(author)
});
} else {
console.log('Warning! Data from API did not contain posts.authors!')
}
).fail(res => console.log(`Ajax call to ${url} failed with message ${res.responseText}!`);
10% of programming is getting it to work. The other 90% is coding for what happens when it doesn't work.