[improvement] Button: jsx (#2447)

packages/button/index.js

@@ -0,0 +1,69 @@
+import createSfc from '../utils/create';
+import createBem from '../utils/bem';
+
+const bem = createBem('van-button');
+
+export default createSfc({
+  name: 'button',
+
+  props: {
+    text: String,
+    block: Boolean,
+    plain: Boolean,
+    round: Boolean,
+    square: Boolean,
+    loading: Boolean,
+    disabled: Boolean,
+    nativeType: String,
+    bottomAction: Boolean,
+    tag: {
+      type: String,
+      default: 'button'
+    },
+    type: {
+      type: String,
+      default: 'default'
+    },
+    size: {
+      type: String,
+      default: 'normal'
+    }
+  },
+
+  methods: {
+    onClick(event) {
+      if (!this.loading && !this.disabled) {
+        this.$emit('click', event);
+      }
+    }
+  },
+
+  render(h) {
+    return (
+      <this.tag
+        type={this.nativeType}
+        disabled={this.disabled}
+        class={bem([
+          this.type,
+          this.size,
+          {
+            block: this.block,
+            plain: this.plain,
+            round: this.round,
+            square: this.square,
+            loading: this.loading,
+            disabled: this.disabled,
+            'bottom-action': this.bottomAction
+          }
+        ])}
+        onClick={this.onClick}
+      >
+        {this.loading ? (
+          <loading size="20px" color={this.type === 'default' ? undefined : ''} />
+        ) : (
+          <span class={bem('text')}>{this.$slots.default || this.text}</span>
+        )}
+      </this.tag>
+    );
+  }
+});