javascript - what is a correct angular pattern for returning multiple *independent* async results from a single service call -


i'm working on search ui. there list view of results , each result can "expanded" show more data. when user expands result, asynchronously fetch details can contain 0 12 pictures. done "detail service," service in angular sense.

now, because aiming "native feel" , these images can weighty, don't want them appear until have finished loading.

the question is: how service notify client (a controller) each image loads?

many articles recommend promises best way this. naively, think return array of promises - 1 each image - resolve after image loads.

this seems heavy-handed solution, requiring loop attaching then() functions arbitrary number of promises.

another popular solution use broadcast() on $rootscope. seems "sloppy" in know exactly "listening" result.

is "array of promises" correct, or there more concise or "angular" way?

note: these independent results , should not chained or composed single promise.

edit: apologize unclear ask. desired functionality each picture appears loaded. aggregating promises undesired. leaves core ask whether promises concise solve this. found think better one, expressed in answers image directive delays display until image loaded. moving logic out of service , directive seems more elegant solution.

i 'array of promises' correct approach.

you can use .all() method takes number of promises arguments (as array). can resolve promise single promise.

returns single promise resolved array/hash of values, each value corresponding promise @ same index/key in promises array/hash. if of promises resolved rejection, resulting promise rejected same rejection value.

    $q.all([firstpromise.then(function(){                              //do                              }),             secondpromise.then(function(){                              //do else                                })            ])      .then(function(){             //do after promises resolved             });

https://docs.angularjs.org/api/ng/service/$q


Comments

Post a Comment

Popular posts from this blog

commonjs - How to write a typescript definition file for a node module that exports a function? -

consider, toml node module can use: // toml.d.ts declare module toml { export function parse(value:string):any; } declare module "toml" { export = toml; } then: /// <reference path="../../../../../defs/toml/toml.d.ts"/> import toml = require('toml'); toml.parse(...); however, node module export single function, such 'glob' ( https://github.com/isaacs/node-glob ). the node usage of module be: var glob = require("glob") glob("*.js", {}, callback(err, files) { ... }); you'd naively expect this: // glob.d.ts declare function globs(paths:string, options:any, callback:{(err:any, files:string[]):void; ...but because typescripts 'import' semantics bit strange, seems can use 'import .. = require()' statement alias modules . trying call: /// <reference path="../../../../../defs/glob/glob.d.ts"/> import blog = require('glob'); results in: error ts2072: mod
Read more

openid - Okta: Failed to get authorization code through API call -

i'm integrating okta own idp server using okta's api. i'm implementing authorization code flow following steps below: in own server, use /api/v1/authn endpoint sessiontoken. use sessiontoken obtain authorization calling endpoint: /oauth2/v1/authorize?client_id=" + clientid + "&sessiontoken=" + sessiontoken + "&response_type=code&response_mode=query&scope=openid&redirect_uri=" + redirecturl + "&state=evanyang&nonce=" it's supposed return response status code 302 , location header containing redirect url code value. however, keep getting response status code 200 , without location header, html body saying "you using unsupported browser." , "javascript disabled on browser." according api documentation: http://developer.okta.com/docs/api/resources/oidc.html#authentication-request , sessiontoken parameter sufficient this: an okta one-time sessiontoken. allows api-based
Read more

thorough guide for profiling racket code -

did googling ("racket profiling", "racket measure performance"), didn't find , there no examples in docs. did google "profile" search on htdp - no luck. (profile (f ...)) output isn't obvious other small snippets. ideally want python's python -m cprofile usage examples. when search "python profiling", both duckduckgo , google give top result: 26.4. python profilers . (although scanned quickly, seems more of reference "thorough usage guide" examples. if had else in mind, perhaps please link that?) the equivalent racket documentation be: profile: statistical profiler . a usage example: #lang racket (require profile) (profile-thunk (thunk (function-to-profile arg0 arg1) )) here (thunk e) convenience (lambda () e) . bigger example: #lang racket (module mod racket (provide f) (define (f) (for/list ([i 10000]) i))) (require (prefix-in mod: 'mod)) (define (f) (for ([i 10000
Read more