1_how_to_use_promises
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How to use promises
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Nodes
promises | |
content | promises |
children | catching_errors, chaining_promises, fetch_API, foundation_async_programming, handlers_attach_promise, obj_ret_async_cur_state (description) |
foundation_async_programming | |
content | foundation of asynchronous programming in JavaScript |
parents | promises |
obj_ret_async_cur_state | |
content | Object returned by an asynchronous function which represents the current state of operation |
parents | promises |
handlers_attach_promise | |
content | handlers attached to promise object are executed when oepration succeeds/fails |
parents | promises |
fetch_API | |
content | fetch() API |
children | promise_replacement_XMLHttpRequest (description) |
parents | promises |
promise_replacement_XMLHttpRequest | |
content | promise-based replacement for XMLHttpRequest |
parents | fetch_API |
chaining_promises | |
content | Chaining Promises |
children | promise_chaining, then_returns_promise |
parents | promises |
promise_chaining | |
content | Promise Chaining: return promise, call then() on it. |
parents | chaining_promises |
then_returns_promise | |
content | then() itself returns a promise, which will be completed with the result of the function passed to it. |
parents | chaining_promises |
catching_errors | |
content | catching errors |
children | catch_method |
parents | promises |
catch_method | |
content | catch() method |
children | called_on_any_failure_when_at_end |
parents | catching_errors |
called_on_any_failure_when_at_end | |
content | when placed at end of chain, will be called when any of the asynchronous functions fail |
parents | catch_method |
promise_terminology | |
content | Promise terminology |
children | rejected, settled, fulfilled, pending |
pending | |
content | pending: promise created, async function created with it has yet to succeed or fail |
parents | promise_terminology |
fulfilled | |
content | Fulfilled: async function suceeded, then() handler called |
parents | promise_terminology |
rejected | |
content | Rejected: async func failed. Catch() handler called. |
parents | promise_terminology |
combining_multiple_promises | |
content | Combining mUltiple promises |
children | promise_all |
promise_all | |
content | promise.all(): takes array of promises and returns single promise |
children | promise_all_fulfilled_rejected, promise_any (fulfilled when any promise in array fulfilled) |
parents | combining_multiple_promises |
settled | |
content | Settled: covers both fulfilled and rejected |
parents | promise_terminology |
promise_all_fulfilled_rejected | |
content | fulfilled when and if all promises fulfilled. rejected when and if any are rejected. |
parents | promise_all |
promise_any | |
content | promise.any(): like promise.all(), but fulfilled when any promises in array are fulfilled |
parents | promise_all |
async_await | |
content | Async and Await |
children | async, await |
await | |
content | await: used inside async function before function call that returns promise. |
children | similar_to_promise_chain, make_async_look_sync (description), only_used_async_or_module |
parents | async_await |
async | |
content | async: keyword before function declaration to make it asynchronous. |
parents | async_await |
make_async_look_sync | |
content | Enables code using async functions to look like synchronous code |
parents | await |
only_used_async_or_module | |
content | Only used in async function, unless code is inside a JS module |
parents | await |
similar_to_promise_chain | |
content | similar to promise chain, await forces async operations to be completed in series |
parents | await |