Merge pull request #3245 from obsidian-tasks-group/multi-line-placeholders

fix: Allow multi-line properties in {{query.file.property('...')}}

Author: claremacrae

resources/sample_vaults/Tasks-Demo/Test Data/query_using_properties.md

@@ -6,7 +6,13 @@ task_instruction: group by filename
 task_instructions: |
   group by root
   group by folder
-  group by filename
+    group by filename
+  # a comment
+    # an indented comment
+task_instructions_with_continuation_line: |
+  path \
+    includes query_using_properties
+task_instruction_with_spaces: "  path includes query_using_properties  "
 ---
 
 # query_using_properties
@@ -24,15 +30,41 @@ ignore global query
 limit 10
 ```
 
+## Use a one-line property: task_instruction_with_spaces
+
+Read a Tasks instruction **that is surrounded by extra spaces** from a property in this file, and embed it in to any number of queries in the file:
+
+```tasks
+explain
+ignore global query
+{{query.file.property('task_instruction_with_spaces')}}
+limit 10
+```
+
 ## Use a multi-line property: task_instructions
 
-This fails as the `task_instructions` contains multiple lines , and placeholders are applied after the query is split at line-endings...
+Read multiple Tasks instructions from a property in this file, and embed them in to any number of queries in the file:
 
 ```tasks
 ignore global query
 folder includes Test Data
 explain
 {{query.file.property('task_instructions')}}
+limit 10
+```
+
+## Use a multi-line property: task_instructions_with_continuation_line
+
+Read multiple Tasks instructions with a continuation line from a property in this file, and embed them in to any number of queries in the file.
+
+Continuation lines are currently unsupported in placeholders.
+
+```tasks
+ignore global query
+folder includes Test Data
+explain
+{{query.file.property('task_instructions_with_continuation_line')}}
+limit 10
 ```
 
 ## Use a list property in a custom filter: root_dirs_to_search

src/Query/Query.ts

@@ -57,15 +57,24 @@ export class Query implements IQuery {
 
         this.debug(`Creating query: ${this.formatQueryForLogging()}`);
 
-        continueLines(source).forEach((statement: Statement) => {
-            const line = this.expandPlaceholders(statement, tasksFile);
+        const anyContinuationLinesRemoved = continueLines(source);
+
+        const anyPlaceholdersExpanded: Statement[] = [];
+        for (const statement of anyContinuationLinesRemoved) {
+            const expandedStatements = this.expandPlaceholders(statement, tasksFile);
             if (this.error !== undefined) {
                 // There was an error expanding placeholders.
                 return;
             }
+            anyPlaceholdersExpanded.push(...expandedStatements);
+        }
 
+        for (const statement of anyPlaceholdersExpanded) {
             try {
-                this.parseLine(line, statement);
+                this.parseLine(statement);
+                if (this.error !== undefined) {
+                    return;
+                }
             } catch (e) {
                 let message;
                 if (e instanceof Error) {
@@ -77,7 +86,7 @@ export class Query implements IQuery {
                 this.setError(message, statement);
                 return;
             }
-        });
+        }
     }
 
     public get filePath(): string | undefined {
@@ -88,7 +97,8 @@ export class Query implements IQuery {
         return this._queryId;
     }
 
-    private parseLine(line: string, statement: Statement) {
+    private parseLine(statement: Statement) {
+        const line = statement.anyPlaceholdersExpanded;
         switch (true) {
             case this.shortModeRegexp.test(line):
                 this._queryLayoutOptions.shortMode = true;
@@ -126,20 +136,19 @@ export class Query implements IQuery {
         return `[${this.source.split('\n').join(' ; ')}]`;
     }
 
-    private expandPlaceholders(statement: Statement, tasksFile: OptionalTasksFile) {
+    private expandPlaceholders(statement: Statement, tasksFile: OptionalTasksFile): Statement[] {
         const source = statement.anyContinuationLinesRemoved;
         if (source.includes('{{') && source.includes('}}')) {
             if (this.tasksFile === undefined) {
                 this._error = `The query looks like it contains a placeholder, with "{{" and "}}"
 but no file path has been supplied, so cannot expand placeholder values.
 The query is:
 ${source}`;
-                return source;
+                return [statement];
             }
         }
 
         // TODO Do not complain about any placeholder errors in comment lines
-        // TODO Show the original and expanded text in explanations
         // TODO Give user error info if they try and put a string in a regex search
         let expandedSource: string = source;
         if (tasksFile) {
@@ -152,13 +161,36 @@ ${source}`;
                 } else {
                     this._error = 'Internal error. expandPlaceholders() threw something other than Error.';
                 }
-                return source;
+                return [statement];
             }
         }
 
-        // Save any expanded text back in to the statement:
-        statement.recordExpandedPlaceholders(expandedSource);
-        return expandedSource;
+        return this.createStatementsFromExpandedPlaceholders(expandedSource, statement);
+    }
+
+    private createStatementsFromExpandedPlaceholders(expandedSource: string, statement: Statement) {
+        // Trim and filter empty lines in one step.
+        const expandedSourceLines = expandedSource
+            .split('\n')
+            .map((line) => line.trim())
+            .filter((line) => line.length > 0);
+
+        if (expandedSourceLines.length === 1) {
+            // Save the single expanded line back into the statement.
+            statement.recordExpandedPlaceholders(expandedSourceLines[0]);
+            return [statement];
+        }
+
+        // Handle multiple-line placeholders.
+        return expandedSourceLines.map((expandedSourceLine, index) => {
+            const counter = `: statement ${index + 1} after expansion of placeholder`;
+            const newStatement = new Statement(
+                statement.rawInstruction + counter,
+                statement.anyContinuationLinesRemoved + counter,
+            );
+            newStatement.recordExpandedPlaceholders(expandedSourceLine);
+            return newStatement;
+        });
     }
 
     /**

src/Renderer/QueryRenderer.ts

@@ -41,8 +41,8 @@ export class QueryRenderer {
         //    not yet available, so empty.
         //  - It does not listen out for edits the properties, so if a property is edited,
         //    the user needs to close and re-open the file.
-        //  - Only single-line properties work. Multiple-line properties give an error message
-        //    'do not understand query'.
+        //  - Multi-line properties are supported, but they cannot contain
+        //    continuation lines.
         const app = this.app;
         const filePath = context.sourcePath;
         const tFile = app.vault.getAbstractFileByPath(filePath);