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65 lines
1.3 KiB
Markdown
65 lines
1.3 KiB
Markdown
# Formula
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Formulas are dynamic document properties that can be set on the fields
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Forumlas are defined as javascript functions and are called whenever any property of the document is updated using the `set` method, or just before inserting or updating the document.
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### Example
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```js
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module.exports = {
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name: "FormulaExample"
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fields: [
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{
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fieldtype: "Float",
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fieldname: "a"
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},
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{
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fieldtype: "Float",
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fieldname: "b"
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}
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{
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fieldtype: "Float",
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fieldname: "c",
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formula: doc => doc.a + doc.b
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}
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]
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}
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```
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## Formula on child tables
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In child tables, both the parent and the child records are passed
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### Example
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```js
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{
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fieldname: "amount",
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fieldtype: "Float",
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formula: (doc, row) => row.qty * row.rate
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}
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```
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## Sequence
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All child tables are executed first and all fields are executed in the sequence as defined in the DocType
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## Fetching Values
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You can use the `getFrom` function to fetch values from another document
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Example:
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```
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{
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"fieldname": "rate",
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"label": "Rate",
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"fieldtype": "Currency",
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formula: (row, doc) => row.rate || doc.getFrom('Item', row.item, 'rate')
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}
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```
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## Async
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Forumlas are evaluated as promises, so you can either directly pass a value or a `Promise` |