> ## Documentation Index > Fetch the complete documentation index at: https://learn.nextedy.com/llms.txt > Use this file to discover all available pages before exploring further. # Context Expressions Reference > Nextedy POWERSHEET configurations support **dynamic value expressions** -- values resolved at runtime based on the current context such as the active document, the logged-in user, URL parameters, or the source entity. export const LastReviewed = ({date}) => { if (!date) return null; const formatted = new Date(`${date}T00:00:00Z`).toLocaleDateString("en-US", { year: "numeric", month: "long", day: "numeric", timeZone: "UTC" }); return

Last reviewed on {formatted}

; }; See also: [Constraints](/powersheet/reference/data-model/constraints) | [Properties](/powersheet/reference/data-model/properties) | [Relationships](/powersheet/reference/data-model/relationships) | [Binding Syntax](/powersheet/reference/sheet-config/binding-syntax) ## Two Expression Notations Powersheet uses two distinct expression notations depending on the configuration layer: diagram | Notation | Syntax | Used In | Expressiveness | | ---------------------- | ------------------------ | -------------------------------------------------------- | --------------------------------- | | **Context expression** | `$context.property.path` | Data model configuration (constraints) | Dot-notation property access only | | **Dynamic value** | `() => expression` | Sheet configuration (`where`, `formula`, `render`, etc.) | Full JavaScript arrow function | If you are editing a **data model** YAML file (`domainModelTypes`, `relationships`), use `$context`. If you are editing a **sheet configuration** YAML file (`sources`, `columns`, `formatters`), use `() =>`. *** ## Context Expression (`$context`) Context expressions use dot-notation to access properties from the runtime context. They are used exclusively in **data model configuration** -- specifically within [constraint](/powersheet/reference/data-model/constraints) definitions on entity types and relationships. ### How It Works A `$context` expression is a property path that Powersheet resolves by traversing the context object at runtime. No JavaScript logic is supported -- only direct property access via dot-separated keys. ### Where It Is Used | Configuration Location | Description | | ------------------------------------ | -------------------------------------------------------------------- | | `domainModelTypes.*.constraints` | Entity type constraints -- scopes `load`, `pick`, or `create` stages | | `relationships.*.direct.constraints` | Direct-direction relationship constraints | | `relationships.*.back.constraints` | Back-direction relationship constraints | ### Available Context Paths | Path | Type | Description | Example Value | | --------------------------------------- | -------- | --------------------------------------- | ----------------------------------- | | `$context.source.type` | `string` | Source entity's Polarion work item type | `"sys_req"` | | `$context.source.document.id` | `string` | Source entity's document ID | `"Requirements/SRS"` | | `$context.source.document.moduleName` | `string` | Source entity's document module name | `"UserNeedSpecification"` | | `$context.source.document.moduleFolder` | `string` | Source entity's document folder path | `"Requirements"` | | `$context.source.document.component` | `string` | Source entity's document component | `"Braking"` | | `$context.source.document.type` | `string` | Source entity's document type | `"systemRequirementsSpecification"` | | `$context.source.document.title` | `string` | Source entity's document title | `"System Requirements"` | Dynamic constraints with `$context` are evaluated **per-row**. Different rows can produce different constraint values depending on their source entity's properties. For example, a `UserNeed` in a "Braking" document produces different constraint values than one in a "Steering" document. ### Context Expression Examples **Filter linked items to the same document component as the source item:** ```yaml theme={null} relationships: - from: DesignRequirement to: SystemRequirement back: name: designRequirements constraints: load: document: component: $context.source.document.component ``` When viewing a `SystemRequirement` from the "Braking" component, only `DesignRequirement` entities from "Braking" documents are loaded. **Filter linked items to the same document as the source item:** ```yaml theme={null} constraints: load: document: moduleName: $context.source.document.moduleName moduleFolder: $context.source.document.moduleFolder ``` This restricts loaded entities to the exact same LiveDoc document as the source entity, matching on both module name and folder. **Filter picker options by source document type:** ```yaml theme={null} constraints: pick: document: type: $context.source.document.type ``` When a user opens a picker dialog, only entities from documents matching the source entity's document type appear as options. ### Complete Data Model Example with Context Expressions ```yaml theme={null} domainModelTypes: UserNeed: polarionType: user_need properties: description: severity: SystemRequirement: polarionType: sys_req properties: description: severity: DesignRequirement: polarionType: des_req properties: description: relationships: - from: SystemRequirement to: UserNeed cardinality: many-to-many storage: linkedWorkItems linkRole: decomposes direct: name: userNeeds back: name: systemRequirements constraints: load: document: component: $context.source.document.component - from: DesignRequirement to: SystemRequirement cardinality: many-to-many storage: linkedWorkItems linkRole: decomposes direct: name: systemRequirements back: name: designRequirements constraints: load: document: moduleName: $context.source.document.moduleName moduleFolder: $context.source.document.moduleFolder pick: document: type: $context.source.document.type ``` In this model, `SystemRequirement` back-navigation to `DesignRequirement` entities filters by both module name and folder at load time, and additionally restricts picker results by document type. *** ## Dynamic Value (`() => expression`) Dynamic values use JavaScript arrow function syntax and are used in **sheet configuration** YAML files. They provide full JavaScript expressiveness for computing values, filtering data, and rendering content at runtime. ### How It Works A `() =>` expression is a JavaScript arrow function that receives a `context` object. Powersheet evaluates the function at runtime and uses the returned value. The expression must be wrapped in quotes within the YAML to preserve the arrow function syntax. ### Where It Is Used | Sheet Configuration Property | Purpose | Returns | | ---------------------------- | ------------------------------------------------ | --------------------------------- | | `sources.query.where` | Filter data with dynamic predicates | Value matching the predicate type | | `sources.entityFactory` | Set initial values for new items | Property value | | `columns.*.formula` | Calculate column values from other properties | Computed value (persisted) | | `columns.*.render` | Custom HTML rendering for cells | HTML string | | `columns.*.display` | Override display value for navigation properties | Display string | | `renderers.*` | Named renderer definitions | HTML string | | `formatters.*.expression` | Conditional formatting expressions | Boolean | `formula` affects **persisted data** -- the calculated value is saved back to the data source. Use `render` if you only need to change how a value is **displayed** without modifying the underlying data. Formatter expressions use a simplified syntax -- they do **not** start with `() =>`. The expression is evaluated as a boolean condition directly (e.g., `"context.item.Probability <= 99"`). ### Context Availability by Location Not all context properties are available in every location. The following table shows which context sub-objects are accessible in each usage location: | Usage Location | `.user` | `.sources` | `.document` | `.item` | `.value` | `.source` | `.entity` | `.parameters` | | ---------------------- | ------- | ---------- | ----------- | ------- | -------- | --------- | --------- | ------------- | | `where` | ✅ | ✅ | ✅ | -- | -- | -- | -- | ✅ | | `entityFactory` | ✅ | ✅ | -- | -- | -- | -- | -- | ✅ | | `formula` | ✅ | ✅ | -- | ✅ | ✅ | ✅ | ✅ | ✅ | | `render` / `renderers` | -- | -- | -- | ✅ | ✅ | -- | -- | -- | | `formatter` | -- | -- | ✅ | ✅ | ✅ | -- | -- | -- | | `display` | -- | -- | -- | ✅ | ✅ | ✅ | -- | -- | ### Dynamic Value Examples **Where clause -- filter by current document:** ```yaml theme={null} sources: - id: requirements query: from: Requirement where: document: moduleName: "==": "() => context.document.moduleName" ``` The sheet loads only `Requirement` entities whose `document.moduleName` matches the current document's module name, scoping results to the active LiveDoc. **Where clause -- filter by today's date:** ```yaml theme={null} where: DueDate: ">": "() => new Date().toISOString()" ``` The resulting value must be in the correct format for the data type. For date fields, use `.toISOString()` to produce the ISO 8601 string that Polarion expects. **Where clause -- combine multiple parameters:** ```yaml theme={null} where: Client: "==": "() => `${context.parameters.client} ${context.parameters.status}`" ``` Template literal syntax allows concatenating multiple URL parameters into a single filter value. **Entity factory -- set initial value from the source entity type:** ```yaml theme={null} sources: - id: design_requirements query: from: DesignRequirement entityFactory: sourceType: "() => context.source.type" ``` When a user creates a new `DesignRequirement` entity in this sheet, the `sourceType` field is automatically populated with the Polarion work item type of the parent/source entity. **Formula -- calculate a value from other item properties:** ```yaml theme={null} columns: totalPrice: formula: "() => context.item.quantity * context.item.unitPrice" ``` The `totalPrice` column value is computed by multiplying `quantity` by `unitPrice`. This calculated value is persisted to the data source. **Renderer -- custom HTML output:** ```yaml theme={null} renderers: linkedItems: "() => context.value.map((item) => `${item.name}`).join(', ')" ``` Renders each linked item name in bold, separated by commas. **Display -- show a property of a linked entity:** ```yaml theme={null} columns: systemRequirement.document: display: "() => context.document.title" ``` Instead of showing the raw document reference, the column displays the document's human-readable title. **Formatter -- conditional styling:** ```yaml theme={null} formatters: criticalHighlight: expression: "context.item.Probability <= 99" style: warningStyle ``` Applies `warningStyle` to cells where the `Probability` value is 99 or below. Note the simplified syntax without `() =>`. *** ## The Context Object The context object provides runtime information to dynamic expressions. Its structure is hierarchical, with properties progressively available depending on the evaluation scope. ### Context Object Structure | Property | Type | Description | Available In | | -------------------------------- | -------- | ----------------------------------------------------------------------------------------------------------------------- | -------------------------------------------- | | `context.parameters` | `object` | URL and configuration parameters as key-value pairs. Access individual parameters via `context.parameters.{paramName}`. | `where`, `entityFactory`, `formula` | | `context.parameters.{paramName}` | `string` | Individual URL parameter value (e.g., `context.parameters.client`) | `where`, `entityFactory`, `formula` | | `context.user` | `object` | Current logged-in Polarion user | `where`, `entityFactory`, `formula` | | `context.user.id` | `string` | User's login ID | `where`, `entityFactory`, `formula` | | `context.user.name` | `string` | User's display name | `where`, `entityFactory`, `formula` | | `context.sources` | `object` | All configured data source definitions from the sheet configuration | `where`, `entityFactory`, `formula` | | `context.document` | `object` | Current document information | `where`, `formatter` | | `context.document.title` | `string` | Document title | `where`, `formatter` | | `context.document.type` | `string` | Document type | `where`, `formatter` | | `context.document.id` | `string` | Document identifier | `where`, `formatter` | | `context.document.moduleName` | `string` | Document module name | `where`, `formatter` | | `context.document.moduleFolder` | `string` | Document folder path | `where`, `formatter` | | `context.document.component` | `string` | Document component | `where`, `formatter` | | `context.tool` | `object` | Current tool information | See application | | `context.tool.type` | `string` | Tool type identifier | See application | | `context.item` | `object` | Current entity (row) with all its properties. Access fields via `context.item.{propertyName}`. | `formula`, `render`, `formatter`, `display` | | `context.source` | `object` | Parent/source entity in relationship contexts. Access its document via `context.source.document.*`. | `formula`, `display`, `$context` expressions | | `context.entity` | `object` | Current entity as a plain object | `formula` | | `context.value` | `any` | Current cell's display value | `formula`, `render`, `formatter`, `display` | ### Context Tree Diagram ``` context +-- parameters URL and configuration parameters (key-value pairs) | +-- {paramName} e.g., context.parameters.client +-- user Current logged-in user | +-- id | +-- name +-- sources All configured data source definitions +-- document Current document information | +-- title | +-- type | +-- id | +-- moduleName | +-- moduleFolder | +-- component +-- tool Current tool information | +-- type +-- item Current entity (per-cell contexts only) | +-- {propertyName} e.g., context.item.StoryPoints +-- source Parent/source entity (relationship contexts) | +-- {propertyName} e.g., context.source.document.component +-- entity Current entity as a plain object +-- value Current cell's display value ``` * `item`, `source`, `entity`, and `value` are only available in **per-cell** contexts (`formula`, `render`, `formatter`, `display`) * `document` is available in `where` clauses and `formatter` expressions * In `$context` expressions (data model constraints), only `source` and its sub-properties are available *** ## Notation Comparison The two expression systems serve complementary purposes. Understanding when to use each prevents configuration errors. | Aspect | `$context` (Model) | `() =>` (Sheet) | | ---------------------- | ----------------------------------------------- | ------------------------------------------------------------- | | **Syntax** | `$context.source.document.component` | `"() => context.document.moduleName"` | | **Language** | Dot-notation path (no logic) | JavaScript arrow function | | **Configuration file** | Data model YAML | Sheet configuration YAML | | **Evaluation** | Per-row, based on source entity | Per-cell or per-query, based on context scope | | **Capabilities** | Property path access only | Arithmetic, string interpolation, array methods, conditionals | | **Use cases** | Constraint scoping by document, type, component | Query filtering, calculated columns, custom rendering | | **YAML quoting** | Not required | Required (wrap in double quotes) | *** ## Quick Reference | I want to... | Notation | Example | | ------------------------------------------------ | ---------- | ------------------------------------------------------------ | | Filter relationship by source document component | `$context` | `component: $context.source.document.component` | | Filter relationship by source document module | `$context` | `moduleName: $context.source.document.moduleName` | | Filter query by current document | `() =>` | `"==": "() => context.document.moduleName"` | | Calculate column from other fields | `() =>` | `formula: "() => context.item.qty * context.item.price"` | | Render custom HTML in a cell | `() =>` | `render: "() => '' + context.value + ''"` | | Set default value from source type | `() =>` | `entityFactory: { sourceType: "() => context.source.type" }` | | Conditionally style a cell | expression | `expression: "context.item.Risk > 50"` | | Filter by today's date | `() =>` | `">": "() => new Date().toISOString()"` | | Show linked entity property | `() =>` | `display: "() => context.document.title"` | *** ## Complete Sheet Configuration Example The following example demonstrates multiple dynamic value expression types in a single sheet configuration: ```yaml theme={null} sources: - id: requirements query: from: Requirement where: document: moduleName: "==": "() => context.document.moduleName" DueDate: ">": "() => new Date().toISOString()" entityFactory: sourceType: "() => context.source.type" columns: title: title: Title hasFocus: true sourceType: title: Source Type isReadOnly: true quantity: title: Quantity unitPrice: title: Unit Price totalPrice: title: Total Price formula: "() => context.item.quantity * context.item.unitPrice" isReadOnly: true systemRequirement.document: display: "() => context.document.title" renderers: linkedItems: "() => context.value.map((item) => `${item.name}`).join(', ')" formatters: criticalHighlight: expression: "context.item.Probability <= 99" style: warningStyle ``` This configuration: 1. **Filters** the `Requirement` source by the current document's module name and future due dates 2. **Pre-fills** the `sourceType` field on new entities from the parent/source entity's work item type 3. **Calculates** `totalPrice` from `quantity` and `unitPrice` (persisted) 4. **Displays** the document title instead of a raw reference 5. **Renders** linked items with bold formatting 6. **Highlights** rows where `Probability` is 99 or below *** ## See Also * [Constraints](/powersheet/reference/data-model/constraints) -- full reference on constraint configuration including stages, operators, and composition * [Columns](/powersheet/reference/sheet-config/columns) -- column configuration properties including `formula`, `render`, and `display` * [Formatters](/powersheet/reference/sheet-config/formatters) -- conditional formatting and style definitions * [Sources](/powersheet/reference/sheet-config/sources) -- source query configuration including `where` and `entityFactory` * [Binding Syntax](/powersheet/reference/sheet-config/binding-syntax) -- dot-notation paths for column keys * [Navigation Directions](/powersheet/reference/data-model/navigation-directions) -- direct and back relationship directions * [Cardinality](/powersheet/reference/data-model/cardinality) -- how relationship cardinality affects expand patterns and column binding