fix(table): column class names should be css friendly

guides/cdk-table.md

@@ -107,6 +107,17 @@ Event and property bindings can be added directly to the row element.
 </cdk-row>
 ```
 
+##### Styling columns
+
+Each header and row cell will be provided a CSS class that includes its column. For example,
+cells that are displayed in the column `name` will be given the class `cdk-column-name`. This allows
+columns to be given styles that will match across the header and rows.
+
+Since columns can be given any string for its name, its possible that it cannot be directly applied
+to the CSS class (e.g. `*nameColumn!`). In these cases, the special characters will be replaced by 
+the `-` character. For example, cells container in a column named `*nameColumn!` will be given
+the class `cdk-column--nameColumn-`.    
+
 #### Connecting the table to a data source
 
 Data is provided to the table through a `DataSource`. When the table receives a data source,

src/cdk/table/cell.ts

@@ -33,13 +33,26 @@ export class CdkHeaderCellDef {
 @Directive({selector: '[cdkColumnDef]'})
 export class CdkColumnDef {
   /** Unique name for this column. */
-  @Input('cdkColumnDef') name: string;
+  @Input('cdkColumnDef')
+  get name(): string { return this._name; }
+  set name(name: string) {
+    this._name = name;
+    this.cssClassFriendlyName = name.replace(/[^a-z0-9_-]/ig, '-');
+  }
+  _name: string;
 
   /** @docs-private */
   @ContentChild(CdkCellDef) cell: CdkCellDef;
 
   /** @docs-private */
   @ContentChild(CdkHeaderCellDef) headerCell: CdkHeaderCellDef;
+
+  /**
+   * Transformed version of the column name that can be used as part of a CSS classname. Excludes
+   * all non-alphanumeric characters and the special characters '-' and '_'. Any characters that
+   * do not match are replaced by the '-' character.
+   */
+  cssClassFriendlyName: string;
 }
 
 /** Header cell template container that adds the right classes and role. */
@@ -52,7 +65,7 @@ export class CdkColumnDef {
 })
 export class CdkHeaderCell {
   constructor(columnDef: CdkColumnDef, elementRef: ElementRef, renderer: Renderer2) {
-    renderer.addClass(elementRef.nativeElement, `cdk-column-${columnDef.name}`);
+    renderer.addClass(elementRef.nativeElement, `cdk-column-${columnDef.cssClassFriendlyName}`);
   }
 }
 
@@ -66,6 +79,6 @@ export class CdkHeaderCell {
 })
 export class CdkCell {
   constructor(columnDef: CdkColumnDef, elementRef: ElementRef, renderer: Renderer2) {
-    renderer.addClass(elementRef.nativeElement, `cdk-column-${columnDef.name}`);
+    renderer.addClass(elementRef.nativeElement, `cdk-column-${columnDef.cssClassFriendlyName}`);
   }
 }

src/cdk/table/table.spec.ts

@@ -29,6 +29,7 @@ describe('CdkTable', () => {
         RowContextCdkTableApp,
         DuplicateColumnDefNameCdkTableApp,
         MissingColumnDefCdkTableApp,
+        CrazyColumnNameCdkTableApp,
       ],
     }).compileComponents();
   }));
@@ -97,6 +98,17 @@ describe('CdkTable', () => {
     });
   });
 
+  it('should be able to apply class-friendly css class names for the column cells', () => {
+    const crazyColumnNameAppFixture = TestBed.createComponent(CrazyColumnNameCdkTableApp);
+    const crazyColumnNameTableElement =
+        crazyColumnNameAppFixture.nativeElement.querySelector('cdk-table');
+    crazyColumnNameAppFixture.detectChanges();
+
+    // Column was named 'crazy-column-NAME-1!@#$%^-_&*()2'
+    expect(getHeaderCells(crazyColumnNameTableElement)[0].classList)
+        .toContain('cdk-column-crazy-column-NAME-1-------_----2');
+  });
+
   it('should disconnect the data source when table is destroyed', () => {
     expect(dataSource.isConnected).toBe(true);
 
@@ -682,6 +694,26 @@ class CustomRoleCdkTableApp {
   @ViewChild(CdkTable) table: CdkTable<TestData>;
 }
 
+@Component({
+  template: `
+    <cdk-table [dataSource]="dataSource">
+      <ng-container [cdkColumnDef]="columnsToRender[0]">
+        <cdk-header-cell *cdkHeaderCellDef> Column A</cdk-header-cell>
+        <cdk-cell *cdkCellDef="let row"> {{row.a}}</cdk-cell>
+      </ng-container>
+
+      <cdk-header-row *cdkHeaderRowDef="columnsToRender"></cdk-header-row>
+      <cdk-row *cdkRowDef="let row; columns: columnsToRender"></cdk-row>
+    </cdk-table>
+  `
+})
+class CrazyColumnNameCdkTableApp {
+  dataSource: FakeDataSource = new FakeDataSource();
+  columnsToRender = ['crazy-column-NAME-1!@#$%^-_&*()2'];
+
+  @ViewChild(CdkTable) table: CdkTable<TestData>;
+}
+
 @Component({
   template: `
     <cdk-table [dataSource]="dataSource">

src/lib/table/cell.ts

@@ -68,7 +68,7 @@ export class MdHeaderCell extends _MdHeaderCell {
               elementRef: ElementRef,
               renderer: Renderer2) {
     super(columnDef, elementRef, renderer);
-    renderer.addClass(elementRef.nativeElement, `mat-column-${columnDef.name}`);
+    renderer.addClass(elementRef.nativeElement, `mat-column-${columnDef.cssClassFriendlyName}`);
   }
 }
 
@@ -85,6 +85,6 @@ export class MdCell extends _MdCell {
               elementRef: ElementRef,
               renderer: Renderer2) {
     super(columnDef, elementRef, renderer);
-    renderer.addClass(elementRef.nativeElement, `mat-column-${columnDef.name}`);
+    renderer.addClass(elementRef.nativeElement, `mat-column-${columnDef.cssClassFriendlyName}`);
   }
 }