Most AT scripts are transformation of some input data (usually queried by selectRecordsAsync) to some output array for updateRecordsAsync or createRecordsAsync.
My usual pattern is:
const table=base.getTable(‘SomeTable’)
…
const query=await table.selectRecordsAsync({fields:[some_fields]})
…
const upd=query.records.map(SOME_FUNCTION)
while (upd.length) await table.updateRecordsAsync(upd.splice(0,50))```
the rest are chain of transformation with map, filter, find, sometimes reduce. JS “array helpers”
forEach is a compact version of for loop, but sometimes script can be written without direct loop command at all.
Beginners usually avoid multiple updates command, but looping single update with updateRecordAsync can cause problem when you have hundreds of records to update, since AT has limit for updates per second.
from example:
// Only up to 50 updates are allowed at one time, so do it in batches
while (updates.length > 0) {
await table.updateRecordsAsync(updates.slice(0, 50));
updates = updates.slice(50);
}
With new JS syntax, this can be rewritten, because splice does both operations: cuts 50 elements from array (updates.slice(50)) and returns them to the function which called it - updateRecordsAsync(updates.slice(0, 50));
Also, 0 considered as ‘falsy’ value, so while (updates.length > 0) can be changed to while(updates.length)
so, it turns to
while (updates.length) await table.updateRecordsAsync(updates.splice(0,50))
(before using functions from other people code, to learn coding instead of learn copy-pasting, you must be sure to understand how they working :grinning: )
there are also two very useful types of data: Set and Map
another good practice: instead of ‘hardcoding’ text values everywhere in code, they should be assigned to variables somewhere at the beginning, sometimes inside single function or array.
for example, script to mark duplicates:
const table=base.getTable('SomeTable')
const [CHECK,MARK,DUP]=['Checkfield','Markfield','Duplicate']
const query=await table.selectRecordsAsync({fields:[CHECK]})
const val=r=>r.getCellValue(CHECK)
const valueset=new Map(query.records.map(rec=>[val(rec),rec.id]))
const others=query.recordIds.filter(id=>(![...valueset.values()].includes(id)))
const dupes=new Set(others.map(id=>val(query.getRecord(id))))
const update=r=>({'id':r.id,'fields':{[MARK]:DUP}})
const upd=query.records.filter(r=>dupes.has(val(r))).map(update)
while (upd.length) await table.updateRecordsAsync(upd.splice(0,50))```
