Mixing
How can I divide a RXJS Observable stream into equal N sized arrays?
Let's say I have an Observable stream created from an array like so:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
mergeMap(items => {
return this.getData(items);
})
);
As this code stands, getData() will be called for each item in the array. What I want to do is divide the items array into N equal sized arrays, then have those arrays emitted instead. Then getData() will be called with the individual arrays rather than each item in the original items array.
Basically I need a variation of the toArray() operator but on only portions of the stream that I pre-define.
rxjs reactive-programming
asked Nov 21 '18 at 5:36
ijjoijjo
232619
add a comment |
Let's say I have an Observable stream created from an array like so:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
mergeMap(items => {
return this.getData(items);
})
);
As this code stands, getData() will be called for each item in the array. What I want to do is divide the items array into N equal sized arrays, then have those arrays emitted instead. Then getData() will be called with the individual arrays rather than each item in the original items array.
Basically I need a variation of the toArray() operator but on only portions of the stream that I pre-define.
rxjs reactive-programming
asked Nov 21 '18 at 5:36
ijjoijjo
232619
add a comment |
Let's say I have an Observable stream created from an array like so:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
mergeMap(items => {
return this.getData(items);
})
);
As this code stands, getData() will be called for each item in the array. What I want to do is divide the items array into N equal sized arrays, then have those arrays emitted instead. Then getData() will be called with the individual arrays rather than each item in the original items array.
Basically I need a variation of the toArray() operator but on only portions of the stream that I pre-define.
rxjs reactive-programming
asked Nov 21 '18 at 5:36
ijjoijjo
232619
Let's say I have an Observable stream created from an array like so:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
mergeMap(items => {
return this.getData(items);
})
);
As this code stands, getData() will be called for each item in the array. What I want to do is divide the items array into N equal sized arrays, then have those arrays emitted instead. Then getData() will be called with the individual arrays rather than each item in the original items array.
Basically I need a variation of the toArray() operator but on only portions of the stream that I pre-define.
rxjs reactive-programming
rxjs reactive-programming
asked Nov 21 '18 at 5:36
ijjoijjo
232619
asked Nov 21 '18 at 5:36
ijjoijjo
232619
asked Nov 21 '18 at 5:36
ijjoijjo
232619
asked Nov 21 '18 at 5:36
ijjoijjo
232619
asked Nov 21 '18 at 5:36
ijjoijjo
232619
232619
add a comment |
add a comment |
1 Answer
1
active
oldest
votes
You need buffer operator which has several variations, which are: buffer, bufferCount, bufferTime, bufferToggle, bufferWhen. Buffer Official Documentation
For example in your case dividing array in 3 size arrays would be:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
bufferCount(3),
mergeMap(items => {
return this.getData(items);
})
);
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
add a comment |
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1 Answer
1
active
oldest
votes
1 Answer
1
active
oldest
votes
active
oldest
votes
active
oldest
votes
You need buffer operator which has several variations, which are: buffer, bufferCount, bufferTime, bufferToggle, bufferWhen. Buffer Official Documentation
For example in your case dividing array in 3 size arrays would be:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
bufferCount(3),
mergeMap(items => {
return this.getData(items);
})
);
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
add a comment |
You need buffer operator which has several variations, which are: buffer, bufferCount, bufferTime, bufferToggle, bufferWhen. Buffer Official Documentation
For example in your case dividing array in 3 size arrays would be:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
bufferCount(3),
mergeMap(items => {
return this.getData(items);
})
);
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
add a comment |
You need buffer operator which has several variations, which are: buffer, bufferCount, bufferTime, bufferToggle, bufferWhen. Buffer Official Documentation
For example in your case dividing array in 3 size arrays would be:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
bufferCount(3),
mergeMap(items => {
return this.getData(items);
})
);
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
You need buffer operator which has several variations, which are: buffer, bufferCount, bufferTime, bufferToggle, bufferWhen. Buffer Official Documentation
For example in your case dividing array in 3 size arrays would be:
const items: Items = [{},{},{},{},{},...];
const obs$ = from(items).pipe(
bufferCount(3),
mergeMap(items => {
return this.getData(items);
})
);
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
answered Nov 21 '18 at 6:18
Goga KoreliGoga Koreli
467213
467213
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
add a comment |
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
How did I miss that - thanks!
– ijjo
Nov 21 '18 at 6:46
add a comment |
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